[FFmpeg-devel] [PATCH v2 13/16] avcodec/dca: add core decoder

foo86 foobaz86 at gmail.com
Thu Jan 21 19:49:02 CET 2016


---
 libavcodec/dca_core.c | 2602 +++++++++++++++++++++++++++++++++++++++++++++++++
 libavcodec/dca_core.h |  206 ++++
 2 files changed, 2808 insertions(+)
 create mode 100644 libavcodec/dca_core.c
 create mode 100644 libavcodec/dca_core.h

diff --git a/libavcodec/dca_core.c b/libavcodec/dca_core.c
new file mode 100644
index 0000000..61f7ff3
--- /dev/null
+++ b/libavcodec/dca_core.c
@@ -0,0 +1,2602 @@
+/*
+ * Copyright (C) 2016 foo86
+ *
+ * This file is part of FFmpeg.
+ *
+ * FFmpeg is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * FFmpeg is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with FFmpeg; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include "dcadec.h"
+#include "dcadata.h"
+#include "dcahuff.h"
+#include "dcamath.h"
+#include "dca_syncwords.h"
+
+#if ARCH_ARM
+#include "arm/dca.h"
+#endif
+
+enum HeaderType {
+    HEADER_CORE,
+    HEADER_XCH,
+    HEADER_XXCH
+};
+
+enum AudioMode {
+    AMODE_MONO,             // Mode 0: A (mono)
+    AMODE_MONO_DUAL,        // Mode 1: A + B (dual mono)
+    AMODE_STEREO,           // Mode 2: L + R (stereo)
+    AMODE_STEREO_SUMDIFF,   // Mode 3: (L+R) + (L-R) (sum-diff)
+    AMODE_STEREO_TOTAL,     // Mode 4: LT + RT (left and right total)
+    AMODE_3F,               // Mode 5: C + L + R
+    AMODE_2F1R,             // Mode 6: L + R + S
+    AMODE_3F1R,             // Mode 7: C + L + R + S
+    AMODE_2F2R,             // Mode 8: L + R + SL + SR
+    AMODE_3F2R,             // Mode 9: C + L + R + SL + SR
+
+    AMODE_COUNT
+};
+
+enum ExtAudioType {
+    EXT_AUDIO_XCH   = 0,
+    EXT_AUDIO_X96   = 2,
+    EXT_AUDIO_XXCH  = 6
+};
+
+enum LFEFlag {
+    LFE_FLAG_NONE,
+    LFE_FLAG_128,
+    LFE_FLAG_64,
+    LFE_FLAG_INVALID
+};
+
+static const int8_t prm_ch_to_spkr_map[AMODE_COUNT][5] = {
+    { DCA_SPEAKER_C,            -1,             -1,             -1,             -1 },
+    { DCA_SPEAKER_L, DCA_SPEAKER_R,             -1,             -1,             -1 },
+    { DCA_SPEAKER_L, DCA_SPEAKER_R,             -1,             -1,             -1 },
+    { DCA_SPEAKER_L, DCA_SPEAKER_R,             -1,             -1,             -1 },
+    { DCA_SPEAKER_L, DCA_SPEAKER_R,             -1,             -1,             -1 },
+    { DCA_SPEAKER_C, DCA_SPEAKER_L, DCA_SPEAKER_R ,             -1,             -1 },
+    { DCA_SPEAKER_L, DCA_SPEAKER_R, DCA_SPEAKER_Cs,             -1,             -1 },
+    { DCA_SPEAKER_C, DCA_SPEAKER_L, DCA_SPEAKER_R , DCA_SPEAKER_Cs,             -1 },
+    { DCA_SPEAKER_L, DCA_SPEAKER_R, DCA_SPEAKER_Ls, DCA_SPEAKER_Rs,             -1 },
+    { DCA_SPEAKER_C, DCA_SPEAKER_L, DCA_SPEAKER_R,  DCA_SPEAKER_Ls, DCA_SPEAKER_Rs }
+};
+
+static const uint8_t audio_mode_ch_mask[AMODE_COUNT] = {
+    DCA_SPEAKER_LAYOUT_MONO,
+    DCA_SPEAKER_LAYOUT_STEREO,
+    DCA_SPEAKER_LAYOUT_STEREO,
+    DCA_SPEAKER_LAYOUT_STEREO,
+    DCA_SPEAKER_LAYOUT_STEREO,
+    DCA_SPEAKER_LAYOUT_3_0,
+    DCA_SPEAKER_LAYOUT_2_1,
+    DCA_SPEAKER_LAYOUT_3_1,
+    DCA_SPEAKER_LAYOUT_2_2,
+    DCA_SPEAKER_LAYOUT_5POINT0
+};
+
+static const uint8_t block_code_nbits[7] = {
+    7, 10, 12, 13, 15, 17, 19
+};
+
+static const uint8_t quant_index_sel_nbits[DCA_CODE_BOOKS] = {
+    1, 2, 2, 2, 2, 3, 3, 3, 3, 3
+};
+
+static const uint8_t quant_index_group_size[DCA_CODE_BOOKS] = {
+    1, 3, 3, 3, 3, 7, 7, 7, 7, 7
+};
+
+typedef struct DCAVLC {
+    int offset;         ///< Code values offset
+    int max_depth;      ///< Parameter for get_vlc2()
+    VLC vlc[7];         ///< Actual codes
+} DCAVLC;
+
+static DCAVLC   vlc_bit_allocation;
+static DCAVLC   vlc_transition_mode;
+static DCAVLC   vlc_scale_factor;
+static DCAVLC   vlc_quant_index[DCA_CODE_BOOKS];
+
+static av_cold void dca_init_vlcs(void)
+{
+    static VLC_TYPE dca_table[23622][2];
+    static int vlcs_initialized = 0;
+    int i, j, k;
+
+    if (vlcs_initialized)
+        return;
+
+#define DCA_INIT_VLC(vlc, a, b, c, d)                                      \
+    do {                                                                   \
+        vlc.table           = &dca_table[ff_dca_vlc_offs[k]];              \
+        vlc.table_allocated = ff_dca_vlc_offs[k + 1] - ff_dca_vlc_offs[k]; \
+        init_vlc(&vlc, a, b, c, 1, 1, d, 2, 2, INIT_VLC_USE_NEW_STATIC);   \
+    } while (0)
+
+    vlc_bit_allocation.offset    = 1;
+    vlc_bit_allocation.max_depth = 2;
+    for (i = 0, k = 0; i < 5; i++, k++)
+        DCA_INIT_VLC(vlc_bit_allocation.vlc[i], bitalloc_12_vlc_bits[i], 12,
+                     bitalloc_12_bits[i], bitalloc_12_codes[i]);
+
+    vlc_scale_factor.offset    = -64;
+    vlc_scale_factor.max_depth = 2;
+    for (i = 0; i < 5; i++, k++)
+        DCA_INIT_VLC(vlc_scale_factor.vlc[i], SCALES_VLC_BITS, 129,
+                     scales_bits[i], scales_codes[i]);
+
+    vlc_transition_mode.offset    = 0;
+    vlc_transition_mode.max_depth = 1;
+    for (i = 0; i < 4; i++, k++)
+        DCA_INIT_VLC(vlc_transition_mode.vlc[i], tmode_vlc_bits[i], 4,
+                     tmode_bits[i], tmode_codes[i]);
+
+    for (i = 0; i < DCA_CODE_BOOKS; i++) {
+        vlc_quant_index[i].offset    = bitalloc_offsets[i];
+        vlc_quant_index[i].max_depth = 1 + (i > 4);
+        for (j = 0; j < quant_index_group_size[i]; j++, k++)
+            DCA_INIT_VLC(vlc_quant_index[i].vlc[j], bitalloc_maxbits[i][j],
+                         bitalloc_sizes[i], bitalloc_bits[i][j], bitalloc_codes[i][j]);
+    }
+
+    vlcs_initialized = 1;
+}
+
+static int get_vlc(GetBitContext *s, DCAVLC *v, int i)
+{
+    return get_vlc2(s, v->vlc[i].table, v->vlc[i].bits, v->max_depth) + v->offset;
+}
+
+static void get_array(GetBitContext *s, int32_t *array, int size, int n)
+{
+    int i;
+
+    for (i = 0; i < size; i++)
+        array[i] = get_sbits(s, n);
+}
+
+// 5.3.1 - Bit stream header
+static int parse_frame_header(DCACoreDecoder *s)
+{
+    int normal_frame, pcmr_index;
+
+    // Frame type
+    normal_frame = get_bits1(&s->gb);
+
+    // Deficit sample count
+    if (get_bits(&s->gb, 5) != DCA_PCMBLOCK_SAMPLES - 1) {
+        av_log(s->avctx, AV_LOG_ERROR, "Deficit samples are not supported\n");
+        return normal_frame ? AVERROR_INVALIDDATA : AVERROR_PATCHWELCOME;
+    }
+
+    // CRC present flag
+    s->crc_present = get_bits1(&s->gb);
+
+    // Number of PCM sample blocks
+    s->npcmblocks = get_bits(&s->gb, 7) + 1;
+    if (s->npcmblocks & (DCA_SUBBAND_SAMPLES - 1)) {
+        av_log(s->avctx, AV_LOG_ERROR, "Unsupported number of PCM sample blocks (%d)\n", s->npcmblocks);
+        return (s->npcmblocks < 6 || normal_frame) ? AVERROR_INVALIDDATA : AVERROR_PATCHWELCOME;
+    }
+
+    // Primary frame byte size
+    s->frame_size = get_bits(&s->gb, 14) + 1;
+    if (s->frame_size < 96) {
+        av_log(s->avctx, AV_LOG_ERROR, "Invalid core frame size (%d bytes)\n", s->frame_size);
+        return AVERROR_INVALIDDATA;
+    }
+
+    // Audio channel arrangement
+    s->audio_mode = get_bits(&s->gb, 6);
+    if (s->audio_mode >= AMODE_COUNT) {
+        av_log(s->avctx, AV_LOG_ERROR, "Unsupported audio channel arrangement (%d)\n", s->audio_mode);
+        return AVERROR_PATCHWELCOME;
+    }
+
+    // Core audio sampling frequency
+    s->sample_rate = avpriv_dca_sample_rates[get_bits(&s->gb, 4)];
+    if (!s->sample_rate) {
+        av_log(s->avctx, AV_LOG_ERROR, "Invalid core audio sampling frequency\n");
+        return AVERROR_INVALIDDATA;
+    }
+
+    // Transmission bit rate
+    s->bit_rate = ff_dca_bit_rates[get_bits(&s->gb, 5)];
+
+    // Reserved field
+    skip_bits1(&s->gb);
+
+    // Embedded dynamic range flag
+    s->drc_present = get_bits1(&s->gb);
+
+    // Embedded time stamp flag
+    s->ts_present = get_bits1(&s->gb);
+
+    // Auxiliary data flag
+    s->aux_present = get_bits1(&s->gb);
+
+    // HDCD mastering flag
+    skip_bits1(&s->gb);
+
+    // Extension audio descriptor flag
+    s->ext_audio_type = get_bits(&s->gb, 3);
+
+    // Extended coding flag
+    s->ext_audio_present = get_bits1(&s->gb);
+
+    // Audio sync word insertion flag
+    s->sync_ssf = get_bits1(&s->gb);
+
+    // Low frequency effects flag
+    s->lfe_present = get_bits(&s->gb, 2);
+    if (s->lfe_present == LFE_FLAG_INVALID) {
+        av_log(s->avctx, AV_LOG_ERROR, "Invalid low frequency effects flag\n");
+        return AVERROR_INVALIDDATA;
+    }
+
+    // Predictor history flag switch
+    s->predictor_history = get_bits1(&s->gb);
+
+    // Header CRC check bytes
+    if (s->crc_present)
+        skip_bits(&s->gb, 16);
+
+    // Multirate interpolator switch
+    s->filter_perfect = get_bits1(&s->gb);
+
+    // Encoder software revision
+    skip_bits(&s->gb, 4);
+
+    // Copy history
+    skip_bits(&s->gb, 2);
+
+    // Source PCM resolution
+    s->source_pcm_res = ff_dca_bits_per_sample[pcmr_index = get_bits(&s->gb, 3)];
+    if (!s->source_pcm_res) {
+        av_log(s->avctx, AV_LOG_ERROR, "Invalid source PCM resolution\n");
+        return AVERROR_INVALIDDATA;
+    }
+    s->es_format = pcmr_index & 1;
+
+    // Front sum/difference flag
+    s->sumdiff_front = get_bits1(&s->gb);
+
+    // Surround sum/difference flag
+    s->sumdiff_surround = get_bits1(&s->gb);
+
+    // Dialog normalization / unspecified
+    skip_bits(&s->gb, 4);
+
+    return 0;
+}
+
+// 5.3.2 - Primary audio coding header
+static int parse_coding_header(DCACoreDecoder *s, enum HeaderType header, int xch_base)
+{
+    int n, ch, nchannels, header_size = 0, header_pos = get_bits_count(&s->gb);
+    unsigned int mask, index;
+
+    if (get_bits_left(&s->gb) < 0)
+        return AVERROR_INVALIDDATA;
+
+    switch (header) {
+    case HEADER_CORE:
+        // Number of subframes
+        s->nsubframes = get_bits(&s->gb, 4) + 1;
+
+        // Number of primary audio channels
+        s->nchannels = get_bits(&s->gb, 3) + 1;
+        if (s->nchannels != ff_dca_channels[s->audio_mode]) {
+            av_log(s->avctx, AV_LOG_ERROR, "Invalid number of primary audio channels (%d) for audio channel arrangement (%d)\n", s->nchannels, s->audio_mode);
+            return AVERROR_INVALIDDATA;
+        }
+        av_assert1(s->nchannels <= DCA_CHANNELS - 2);
+
+        s->ch_mask = audio_mode_ch_mask[s->audio_mode];
+
+        // Add LFE channel if present
+        if (s->lfe_present)
+            s->ch_mask |= DCA_SPEAKER_MASK_LFE1;
+        break;
+
+    case HEADER_XCH:
+        s->nchannels = ff_dca_channels[s->audio_mode] + 1;
+        av_assert1(s->nchannels <= DCA_CHANNELS - 1);
+        s->ch_mask |= DCA_SPEAKER_MASK_Cs;
+        break;
+
+    case HEADER_XXCH:
+        // Channel set header length
+        header_size = get_bits(&s->gb, 7) + 1;
+
+        // Check CRC
+        if (s->xxch_crc_present
+            && (s->avctx->err_recognition & (AV_EF_CRCCHECK | AV_EF_CAREFUL))
+            && ff_dca_check_crc(&s->gb, header_pos, header_pos + header_size * 8)) {
+            av_log(s->avctx, AV_LOG_ERROR, "Invalid XXCH channel set header checksum\n");
+            return AVERROR_INVALIDDATA;
+        }
+
+        // Number of channels in a channel set
+        nchannels = get_bits(&s->gb, 3) + 1;
+        if (nchannels > DCA_XXCH_CHANNELS_MAX) {
+            avpriv_request_sample(s->avctx, "%d XXCH channels", nchannels);
+            return AVERROR_PATCHWELCOME;
+        }
+        s->nchannels = ff_dca_channels[s->audio_mode] + nchannels;
+        av_assert1(s->nchannels <= DCA_CHANNELS);
+
+        // Loudspeaker layout mask
+        mask = get_bits_long(&s->gb, s->xxch_mask_nbits - DCA_SPEAKER_Cs);
+        s->xxch_spkr_mask = mask << DCA_SPEAKER_Cs;
+
+        if (av_popcount(s->xxch_spkr_mask) != nchannels) {
+            av_log(s->avctx, AV_LOG_ERROR, "Invalid XXCH speaker layout mask (%#x)\n", s->xxch_spkr_mask);
+            return AVERROR_INVALIDDATA;
+        }
+
+        if (s->xxch_core_mask & s->xxch_spkr_mask) {
+            av_log(s->avctx, AV_LOG_ERROR, "XXCH speaker layout mask (%#x) overlaps with core (%#x)\n", s->xxch_spkr_mask, s->xxch_core_mask);
+            return AVERROR_INVALIDDATA;
+        }
+
+        // Combine core and XXCH masks together
+        s->ch_mask = s->xxch_core_mask | s->xxch_spkr_mask;
+
+        // Downmix coefficients present in stream
+        if (get_bits1(&s->gb)) {
+            int *coeff_ptr = s->xxch_dmix_coeff;
+
+            // Downmix already performed by encoder
+            s->xxch_dmix_embedded = get_bits1(&s->gb);
+
+            // Downmix scale factor
+            index = get_bits(&s->gb, 6) * 4 - FF_DCA_DMIXTABLE_OFFSET - 3;
+            if (index >= FF_DCA_INV_DMIXTABLE_SIZE) {
+                av_log(s->avctx, AV_LOG_ERROR, "Invalid XXCH downmix scale index (%d)\n", index);
+                return AVERROR_INVALIDDATA;
+            }
+            s->xxch_dmix_scale_inv = ff_dca_inv_dmixtable[index];
+
+            // Downmix channel mapping mask
+            for (ch = 0; ch < nchannels; ch++) {
+                mask = get_bits_long(&s->gb, s->xxch_mask_nbits);
+                if ((mask & s->xxch_core_mask) != mask) {
+                    av_log(s->avctx, AV_LOG_ERROR, "Invalid XXCH downmix channel mapping mask (%#x)\n", mask);
+                    return AVERROR_INVALIDDATA;
+                }
+                s->xxch_dmix_mask[ch] = mask;
+            }
+
+            // Downmix coefficients
+            for (ch = 0; ch < nchannels; ch++) {
+                for (n = 0; n < s->xxch_mask_nbits; n++) {
+                    if (s->xxch_dmix_mask[ch] & (1U << n)) {
+                        int code = get_bits(&s->gb, 7);
+                        int sign = (code >> 6) - 1;
+                        if (code &= 63) {
+                            index = code * 4 - 3;
+                            if (index >= FF_DCA_DMIXTABLE_SIZE) {
+                                av_log(s->avctx, AV_LOG_ERROR, "Invalid XXCH downmix coefficient index (%d)\n", index);
+                                return AVERROR_INVALIDDATA;
+                            }
+                            *coeff_ptr++ = (ff_dca_dmixtable[index] ^ sign) - sign;
+                        } else {
+                            *coeff_ptr++ = 0;
+                        }
+                    }
+                }
+            }
+        } else {
+            s->xxch_dmix_embedded = 0;
+        }
+
+        break;
+    }
+
+    // Subband activity count
+    for (ch = xch_base; ch < s->nchannels; ch++) {
+        s->nsubbands[ch] = get_bits(&s->gb, 5) + 2;
+        if (s->nsubbands[ch] > DCA_SUBBANDS) {
+            av_log(s->avctx, AV_LOG_ERROR, "Invalid subband activity count\n");
+            return AVERROR_INVALIDDATA;
+        }
+    }
+
+    // High frequency VQ start subband
+    for (ch = xch_base; ch < s->nchannels; ch++)
+        s->subband_vq_start[ch] = get_bits(&s->gb, 5) + 1;
+
+    // Joint intensity coding index
+    for (ch = xch_base; ch < s->nchannels; ch++) {
+        if ((n = get_bits(&s->gb, 3)) && header == HEADER_XXCH)
+            n += xch_base - 1;
+        if (n > s->nchannels) {
+            av_log(s->avctx, AV_LOG_ERROR, "Invalid joint intensity coding index\n");
+            return AVERROR_INVALIDDATA;
+        }
+        s->joint_intensity_index[ch] = n;
+    }
+
+    // Transient mode code book
+    for (ch = xch_base; ch < s->nchannels; ch++)
+        s->transition_mode_sel[ch] = get_bits(&s->gb, 2);
+
+    // Scale factor code book
+    for (ch = xch_base; ch < s->nchannels; ch++) {
+        s->scale_factor_sel[ch] = get_bits(&s->gb, 3);
+        if (s->scale_factor_sel[ch] == 7) {
+            av_log(s->avctx, AV_LOG_ERROR, "Invalid scale factor code book\n");
+            return AVERROR_INVALIDDATA;
+        }
+    }
+
+    // Bit allocation quantizer select
+    for (ch = xch_base; ch < s->nchannels; ch++) {
+        s->bit_allocation_sel[ch] = get_bits(&s->gb, 3);
+        if (s->bit_allocation_sel[ch] == 7) {
+            av_log(s->avctx, AV_LOG_ERROR, "Invalid bit allocation quantizer select\n");
+            return AVERROR_INVALIDDATA;
+        }
+    }
+
+    // Quantization index codebook select
+    for (n = 0; n < DCA_CODE_BOOKS; n++)
+        for (ch = xch_base; ch < s->nchannels; ch++)
+            s->quant_index_sel[ch][n] = get_bits(&s->gb, quant_index_sel_nbits[n]);
+
+    // Scale factor adjustment index
+    for (n = 0; n < DCA_CODE_BOOKS; n++)
+        for (ch = xch_base; ch < s->nchannels; ch++)
+            if (s->quant_index_sel[ch][n] < quant_index_group_size[n])
+                s->scale_factor_adj[ch][n] = ff_dca_scale_factor_adj[get_bits(&s->gb, 2)];
+
+    if (header == HEADER_XXCH) {
+        // Reserved
+        // Byte align
+        // CRC16 of channel set header
+        if (ff_dca_seek_bits(&s->gb, header_pos + header_size * 8)) {
+            av_log(s->avctx, AV_LOG_ERROR, "Read past end of XXCH channel set header\n");
+            return AVERROR_INVALIDDATA;
+        }
+    } else {
+        // Audio header CRC check word
+        if (s->crc_present)
+            skip_bits(&s->gb, 16);
+    }
+
+    return 0;
+}
+
+static inline int parse_scale(DCACoreDecoder *s, int *scale_index, int sel)
+{
+    const uint32_t *scale_table;
+    unsigned int scale_size;
+
+    // Select the root square table
+    if (sel > 5) {
+        scale_table = ff_dca_scale_factor_quant7;
+        scale_size = FF_ARRAY_ELEMS(ff_dca_scale_factor_quant7);
+    } else {
+        scale_table = ff_dca_scale_factor_quant6;
+        scale_size = FF_ARRAY_ELEMS(ff_dca_scale_factor_quant6);
+    }
+
+    // If Huffman code was used, the difference of scales was encoded
+    if (sel < 5)
+        *scale_index += get_vlc(&s->gb, &vlc_scale_factor, sel);
+    else
+        *scale_index = get_bits(&s->gb, sel + 1);
+
+    // Look up scale factor from the root square table
+    if ((unsigned int)*scale_index >= scale_size) {
+        av_log(s->avctx, AV_LOG_ERROR, "Invalid scale factor index\n");
+        return AVERROR_INVALIDDATA;
+    }
+
+    return scale_table[*scale_index];
+}
+
+static inline int parse_joint_scale(DCACoreDecoder *s, int sel)
+{
+    int scale_index;
+
+    // Absolute value was encoded even when Huffman code was used
+    if (sel < 5)
+        scale_index = get_vlc(&s->gb, &vlc_scale_factor, sel);
+    else
+        scale_index = get_bits(&s->gb, sel + 1);
+
+    // Bias by 64
+    scale_index += 64;
+
+    // Look up joint scale factor
+    if ((unsigned int)scale_index >= FF_ARRAY_ELEMS(ff_dca_joint_scale_factors)) {
+        av_log(s->avctx, AV_LOG_ERROR, "Invalid joint scale factor index\n");
+        return AVERROR_INVALIDDATA;
+    }
+
+    return ff_dca_joint_scale_factors[scale_index];
+}
+
+// 5.4.1 - Primary audio coding side information
+static int parse_subframe_header(DCACoreDecoder *s, int sf,
+                                 enum HeaderType header, int xch_base)
+{
+    int ch, band, ret;
+
+    if (get_bits_left(&s->gb) < 0)
+        return AVERROR_INVALIDDATA;
+
+    if (header == HEADER_CORE) {
+        // Subsubframe count
+        s->nsubsubframes[sf] = get_bits(&s->gb, 2) + 1;
+
+        // Partial subsubframe sample count
+        skip_bits(&s->gb, 3);
+    }
+
+    // Prediction mode
+    for (ch = xch_base; ch < s->nchannels; ch++)
+        for (band = 0; band < s->nsubbands[ch]; band++)
+            s->prediction_mode[ch][band] = get_bits1(&s->gb);
+
+    // Prediction coefficients VQ address
+    for (ch = xch_base; ch < s->nchannels; ch++)
+        for (band = 0; band < s->nsubbands[ch]; band++)
+            if (s->prediction_mode[ch][band])
+                s->prediction_vq_index[ch][band] = get_bits(&s->gb, 12);
+
+    // Bit allocation index
+    for (ch = xch_base; ch < s->nchannels; ch++) {
+        int sel = s->bit_allocation_sel[ch];
+
+        for (band = 0; band < s->subband_vq_start[ch]; band++) {
+            int abits;
+
+            if (sel < 5)
+                abits = get_vlc(&s->gb, &vlc_bit_allocation, sel);
+            else
+                abits = get_bits(&s->gb, sel - 1);
+
+            if (abits > DCA_ABITS_MAX) {
+                av_log(s->avctx, AV_LOG_ERROR, "Invalid bit allocation index\n");
+                return AVERROR_INVALIDDATA;
+            }
+
+            s->bit_allocation[ch][band] = abits;
+        }
+    }
+
+    // Transition mode
+    for (ch = xch_base; ch < s->nchannels; ch++) {
+        // Clear transition mode for all subbands
+        memset(s->transition_mode[sf][ch], 0, sizeof(s->transition_mode[0][0]));
+
+        // Transient possible only if more than one subsubframe
+        if (s->nsubsubframes[sf] > 1) {
+            int sel = s->transition_mode_sel[ch];
+            for (band = 0; band < s->subband_vq_start[ch]; band++)
+                if (s->bit_allocation[ch][band])
+                    s->transition_mode[sf][ch][band] = get_vlc(&s->gb, &vlc_transition_mode, sel);
+        }
+    }
+
+    // Scale factors
+    for (ch = xch_base; ch < s->nchannels; ch++) {
+        int sel = s->scale_factor_sel[ch];
+        int scale_index = 0;
+
+        // Extract scales for subbands up to VQ
+        for (band = 0; band < s->subband_vq_start[ch]; band++) {
+            if (s->bit_allocation[ch][band]) {
+                if ((ret = parse_scale(s, &scale_index, sel)) < 0)
+                    return ret;
+                s->scale_factors[ch][band][0] = ret;
+                if (s->transition_mode[sf][ch][band]) {
+                    if ((ret = parse_scale(s, &scale_index, sel)) < 0)
+                        return ret;
+                    s->scale_factors[ch][band][1] = ret;
+                }
+            } else {
+                s->scale_factors[ch][band][0] = 0;
+            }
+        }
+
+        // High frequency VQ subbands
+        for (band = s->subband_vq_start[ch]; band < s->nsubbands[ch]; band++) {
+            if ((ret = parse_scale(s, &scale_index, sel)) < 0)
+                return ret;
+            s->scale_factors[ch][band][0] = ret;
+        }
+    }
+
+    // Joint subband codebook select
+    for (ch = xch_base; ch < s->nchannels; ch++) {
+        if (s->joint_intensity_index[ch]) {
+            s->joint_scale_sel[ch] = get_bits(&s->gb, 3);
+            if (s->joint_scale_sel[ch] == 7) {
+                av_log(s->avctx, AV_LOG_ERROR, "Invalid joint scale factor code book\n");
+                return AVERROR_INVALIDDATA;
+            }
+        }
+    }
+
+    // Scale factors for joint subband coding
+    for (ch = xch_base; ch < s->nchannels; ch++) {
+        int src_ch = s->joint_intensity_index[ch] - 1;
+        if (src_ch >= 0) {
+            int sel = s->joint_scale_sel[ch];
+            for (band = s->nsubbands[ch]; band < s->nsubbands[src_ch]; band++) {
+                if ((ret = parse_joint_scale(s, sel)) < 0)
+                    return ret;
+                s->joint_scale_factors[ch][band] = ret;
+            }
+        }
+    }
+
+    // Dynamic range coefficient
+    if (s->drc_present && header == HEADER_CORE)
+        skip_bits(&s->gb, 8);
+
+    // Side information CRC check word
+    if (s->crc_present)
+        skip_bits(&s->gb, 16);
+
+    return 0;
+}
+
+#ifndef decode_blockcodes
+static inline int decode_blockcodes(int code1, int code2, int levels, int32_t *audio)
+{
+    int offset = (levels - 1) / 2;
+    int n, div;
+
+    for (n = 0; n < DCA_SUBBAND_SAMPLES / 2; n++) {
+        div = FASTDIV(code1, levels);
+        audio[n] = code1 - div * levels - offset;
+        code1 = div;
+    }
+    for (; n < DCA_SUBBAND_SAMPLES; n++) {
+        div = FASTDIV(code2, levels);
+        audio[n] = code2 - div * levels - offset;
+        code2 = div;
+    }
+
+    return code1 | code2;
+}
+#endif
+
+static inline int parse_block_codes(DCACoreDecoder *s, int32_t *audio, int abits)
+{
+    // Extract block code indices from the bit stream
+    int code1 = get_bits(&s->gb, block_code_nbits[abits - 1]);
+    int code2 = get_bits(&s->gb, block_code_nbits[abits - 1]);
+    int levels = ff_dca_quant_levels[abits];
+
+    // Look up samples from the block code book
+    if (decode_blockcodes(code1, code2, levels, audio)) {
+        av_log(s->avctx, AV_LOG_ERROR, "Failed to decode block code(s)\n");
+        return AVERROR_INVALIDDATA;
+    }
+
+    return 0;
+}
+
+static inline int parse_huffman_codes(DCACoreDecoder *s, int32_t *audio, int abits, int sel)
+{
+    int i;
+
+    // Extract Huffman codes from the bit stream
+    for (i = 0; i < DCA_SUBBAND_SAMPLES; i++)
+        audio[i] = get_vlc(&s->gb, &vlc_quant_index[abits - 1], sel);
+
+    return 1;
+}
+
+static inline int extract_audio(DCACoreDecoder *s, int32_t *audio, int abits, int ch)
+{
+    av_assert1(abits >= 0 && abits <= DCA_ABITS_MAX);
+
+    if (abits == 0) {
+        // No bits allocated
+        memset(audio, 0, DCA_SUBBAND_SAMPLES * sizeof(*audio));
+        return 0;
+    }
+
+    if (abits <= DCA_CODE_BOOKS) {
+        int sel = s->quant_index_sel[ch][abits - 1];
+        if (sel < quant_index_group_size[abits - 1]) {
+            // Huffman codes
+            return parse_huffman_codes(s, audio, abits, sel);
+        }
+        if (abits <= 7) {
+            // Block codes
+            return parse_block_codes(s, audio, abits);
+        }
+    }
+
+    // No further encoding
+    get_array(&s->gb, audio, DCA_SUBBAND_SAMPLES, abits - 3);
+    return 0;
+}
+
+static inline void dequantize(int32_t *output, const int32_t *input,
+                              int32_t step_size, int32_t scale, int residual)
+{
+    // Account for quantizer step size
+    int64_t step_scale = (int64_t)step_size * scale;
+    int n, shift = 0;
+
+    // Limit scale factor resolution to 22 bits
+    if (step_scale > (1 << 23)) {
+        shift = av_log2(step_scale >> 23) + 1;
+        step_scale >>= shift;
+    }
+
+    // Scale the samples
+    if (residual) {
+        for (n = 0; n < DCA_SUBBAND_SAMPLES; n++)
+            output[n] += clip23(norm__(input[n] * step_scale, 22 - shift));
+    } else {
+        for (n = 0; n < DCA_SUBBAND_SAMPLES; n++)
+            output[n]  = clip23(norm__(input[n] * step_scale, 22 - shift));
+    }
+}
+
+static inline void inverse_adpcm(int32_t **subband_samples,
+                                 const int16_t *vq_index,
+                                 const int8_t *prediction_mode,
+                                 int sb_start, int sb_end,
+                                 int ofs, int len)
+{
+    int i, j, k;
+
+    for (i = sb_start; i < sb_end; i++) {
+        if (prediction_mode[i]) {
+            const int16_t *coeff = ff_dca_adpcm_vb[vq_index[i]];
+            int32_t *ptr = subband_samples[i] + ofs;
+            for (j = 0; j < len; j++) {
+                int64_t err = 0;
+                for (k = 0; k < DCA_ADPCM_COEFFS; k++)
+                    err += (int64_t)ptr[j - k - 1] * coeff[k];
+                ptr[j] = clip23(ptr[j] + clip23(norm13(err)));
+            }
+        }
+    }
+}
+
+// 5.5 - Primary audio data arrays
+static int parse_subframe_audio(DCACoreDecoder *s, int sf, enum HeaderType header,
+                                int xch_base, int *sub_pos, int *lfe_pos)
+{
+    int32_t audio[16], scale;
+    int n, ssf, ofs, ch, band;
+
+    // Check number of subband samples in this subframe
+    int nsamples = s->nsubsubframes[sf] * DCA_SUBBAND_SAMPLES;
+    if (*sub_pos + nsamples > s->npcmblocks) {
+        av_log(s->avctx, AV_LOG_ERROR, "Subband sample buffer overflow\n");
+        return AVERROR_INVALIDDATA;
+    }
+
+    if (get_bits_left(&s->gb) < 0)
+        return AVERROR_INVALIDDATA;
+
+    // VQ encoded subbands
+    for (ch = xch_base; ch < s->nchannels; ch++) {
+        int32_t vq_index[DCA_SUBBANDS];
+
+        for (band = s->subband_vq_start[ch]; band < s->nsubbands[ch]; band++)
+            // Extract the VQ address from the bit stream
+            vq_index[band] = get_bits(&s->gb, 10);
+
+        if (s->subband_vq_start[ch] < s->nsubbands[ch]) {
+            s->dcadsp->decode_hf(s->subband_samples[ch], vq_index,
+                                 ff_dca_high_freq_vq, s->scale_factors[ch],
+                                 s->subband_vq_start[ch], s->nsubbands[ch],
+                                 *sub_pos, nsamples);
+        }
+    }
+
+    // Low frequency effect data
+    if (s->lfe_present && header == HEADER_CORE) {
+        unsigned int index;
+
+        // Determine number of LFE samples in this subframe
+        int nlfesamples = 2 * s->lfe_present * s->nsubsubframes[sf];
+        av_assert1((unsigned int)nlfesamples <= FF_ARRAY_ELEMS(audio));
+
+        // Extract LFE samples from the bit stream
+        get_array(&s->gb, audio, nlfesamples, 8);
+
+        // Extract scale factor index from the bit stream
+        index = get_bits(&s->gb, 8);
+        if (index >= FF_ARRAY_ELEMS(ff_dca_scale_factor_quant7)) {
+            av_log(s->avctx, AV_LOG_ERROR, "Invalid LFE scale factor index\n");
+            return AVERROR_INVALIDDATA;
+        }
+
+        // Look up the 7-bit root square quantization table
+        scale = ff_dca_scale_factor_quant7[index];
+
+        // Account for quantizer step size which is 0.035
+        scale = mul23(4697620 /* 0.035 * (1 << 27) */, scale);
+
+        // Scale and take the LFE samples
+        for (n = 0, ofs = *lfe_pos; n < nlfesamples; n++, ofs++)
+            s->lfe_samples[ofs] = clip23(audio[n] * scale >> 4);
+
+        // Advance LFE sample pointer for the next subframe
+        *lfe_pos = ofs;
+    }
+
+    // Audio data
+    for (ssf = 0, ofs = *sub_pos; ssf < s->nsubsubframes[sf]; ssf++) {
+        for (ch = xch_base; ch < s->nchannels; ch++) {
+            if (get_bits_left(&s->gb) < 0)
+                return AVERROR_INVALIDDATA;
+
+            // Not high frequency VQ subbands
+            for (band = 0; band < s->subband_vq_start[ch]; band++) {
+                int ret, trans_ssf, abits = s->bit_allocation[ch][band];
+                int32_t step_size;
+
+                // Extract bits from the bit stream
+                if ((ret = extract_audio(s, audio, abits, ch)) < 0)
+                    return ret;
+
+                // Select quantization step size table and look up
+                // quantization step size
+                if (s->bit_rate == 3)
+                    step_size = ff_dca_lossless_quant[abits];
+                else
+                    step_size = ff_dca_lossy_quant[abits];
+
+                // Identify transient location
+                trans_ssf = s->transition_mode[sf][ch][band];
+
+                // Determine proper scale factor
+                if (trans_ssf == 0 || ssf < trans_ssf)
+                    scale = s->scale_factors[ch][band][0];
+                else
+                    scale = s->scale_factors[ch][band][1];
+
+                // Adjust scale factor when SEL indicates Huffman code
+                if (ret > 0) {
+                    int64_t adj = s->scale_factor_adj[ch][abits - 1];
+                    scale = clip23(adj * scale >> 22);
+                }
+
+                dequantize(s->subband_samples[ch][band] + ofs,
+                           audio, step_size, scale, 0);
+            }
+        }
+
+        // DSYNC
+        if ((ssf == s->nsubsubframes[sf] - 1 || s->sync_ssf) && get_bits(&s->gb, 16) != 0xffff) {
+            av_log(s->avctx, AV_LOG_ERROR, "DSYNC check failed\n");
+            return AVERROR_INVALIDDATA;
+        }
+
+        ofs += DCA_SUBBAND_SAMPLES;
+    }
+
+    // Inverse ADPCM
+    for (ch = xch_base; ch < s->nchannels; ch++) {
+        inverse_adpcm(s->subband_samples[ch], s->prediction_vq_index[ch],
+                      s->prediction_mode[ch], 0, s->nsubbands[ch],
+                      *sub_pos, nsamples);
+    }
+
+    // Joint subband coding
+    for (ch = xch_base; ch < s->nchannels; ch++) {
+        int src_ch = s->joint_intensity_index[ch] - 1;
+        if (src_ch >= 0) {
+            s->dcadsp->decode_joint(s->subband_samples[ch], s->subband_samples[src_ch],
+                                    s->joint_scale_factors[ch], s->nsubbands[ch],
+                                    s->nsubbands[src_ch], *sub_pos, nsamples);
+        }
+    }
+
+    // Advance subband sample pointer for the next subframe
+    *sub_pos = ofs;
+    return 0;
+}
+
+static void erase_adpcm_history(DCACoreDecoder *s)
+{
+    int ch, band;
+
+    // Erase ADPCM history from previous frame if
+    // predictor history switch was disabled
+    for (ch = 0; ch < DCA_CHANNELS; ch++)
+        for (band = 0; band < DCA_SUBBANDS; band++)
+            AV_ZERO128(s->subband_samples[ch][band] - DCA_ADPCM_COEFFS);
+}
+
+static int alloc_sample_buffer(DCACoreDecoder *s)
+{
+    int nchsamples = DCA_ADPCM_COEFFS + s->npcmblocks;
+    int nframesamples = nchsamples * DCA_CHANNELS * DCA_SUBBANDS;
+    int nlfesamples = DCA_LFE_HISTORY + s->npcmblocks / 2;
+    unsigned int size = s->subband_size;
+    int ch, band;
+
+    // Reallocate subband sample buffer
+    av_fast_mallocz(&s->subband_buffer, &s->subband_size,
+                    (nframesamples + nlfesamples) * sizeof(int32_t));
+    if (!s->subband_buffer)
+        return AVERROR(ENOMEM);
+
+    if (size != s->subband_size) {
+        for (ch = 0; ch < DCA_CHANNELS; ch++)
+            for (band = 0; band < DCA_SUBBANDS; band++)
+                s->subband_samples[ch][band] = s->subband_buffer +
+                    (ch * DCA_SUBBANDS + band) * nchsamples + DCA_ADPCM_COEFFS;
+        s->lfe_samples = s->subband_buffer + nframesamples;
+    }
+
+    if (!s->predictor_history)
+        erase_adpcm_history(s);
+
+    return 0;
+}
+
+static int parse_frame_data(DCACoreDecoder *s, enum HeaderType header, int xch_base)
+{
+    int sf, ch, ret, band, sub_pos, lfe_pos;
+
+    if ((ret = parse_coding_header(s, header, xch_base)) < 0)
+        return ret;
+
+    for (sf = 0, sub_pos = 0, lfe_pos = DCA_LFE_HISTORY; sf < s->nsubframes; sf++) {
+        if ((ret = parse_subframe_header(s, sf, header, xch_base)) < 0)
+            return ret;
+        if ((ret = parse_subframe_audio(s, sf, header, xch_base, &sub_pos, &lfe_pos)) < 0)
+            return ret;
+    }
+
+    for (ch = xch_base; ch < s->nchannels; ch++) {
+        // Determine number of active subbands for this channel
+        int nsubbands = s->nsubbands[ch];
+        if (s->joint_intensity_index[ch])
+            nsubbands = FFMAX(nsubbands, s->nsubbands[s->joint_intensity_index[ch] - 1]);
+
+        // Update history for ADPCM
+        for (band = 0; band < nsubbands; band++) {
+            int32_t *samples = s->subband_samples[ch][band] - DCA_ADPCM_COEFFS;
+            AV_COPY128(samples, samples + s->npcmblocks);
+        }
+
+        // Clear inactive subbands
+        for (; band < DCA_SUBBANDS; band++) {
+            int32_t *samples = s->subband_samples[ch][band] - DCA_ADPCM_COEFFS;
+            memset(samples, 0, (DCA_ADPCM_COEFFS + s->npcmblocks) * sizeof(int32_t));
+        }
+    }
+
+    return 0;
+}
+
+static int parse_xch_frame(DCACoreDecoder *s)
+{
+    int ret;
+
+    if (s->ch_mask & DCA_SPEAKER_MASK_Cs) {
+        av_log(s->avctx, AV_LOG_ERROR, "XCH with Cs speaker already present\n");
+        return AVERROR_INVALIDDATA;
+    }
+
+    if ((ret = parse_frame_data(s, HEADER_XCH, s->nchannels)) < 0)
+        return ret;
+
+    // Seek to the end of core frame, don't trust XCH frame size
+    if (ff_dca_seek_bits(&s->gb, s->frame_size * 8)) {
+        av_log(s->avctx, AV_LOG_ERROR, "Read past end of XCH frame\n");
+        return AVERROR_INVALIDDATA;
+    }
+
+    return 0;
+}
+
+static int parse_xxch_frame(DCACoreDecoder *s)
+{
+    int xxch_nchsets, xxch_frame_size;
+    int ret, mask, header_size, header_pos = get_bits_count(&s->gb);
+
+    // XXCH sync word
+    if (get_bits_long(&s->gb, 32) != DCA_SYNCWORD_XXCH) {
+        av_log(s->avctx, AV_LOG_ERROR, "Invalid XXCH sync word\n");
+        return AVERROR_INVALIDDATA;
+    }
+
+    // XXCH frame header length
+    header_size = get_bits(&s->gb, 6) + 1;
+
+    // Check XXCH frame header CRC
+    if ((s->avctx->err_recognition & (AV_EF_CRCCHECK | AV_EF_CAREFUL))
+        && ff_dca_check_crc(&s->gb, header_pos + 32, header_pos + header_size * 8)) {
+        av_log(s->avctx, AV_LOG_ERROR, "Invalid XXCH frame header checksum\n");
+        return AVERROR_INVALIDDATA;
+    }
+
+    // CRC presence flag for channel set header
+    s->xxch_crc_present = get_bits1(&s->gb);
+
+    // Number of bits for loudspeaker mask
+    s->xxch_mask_nbits = get_bits(&s->gb, 5) + 1;
+    if (s->xxch_mask_nbits <= DCA_SPEAKER_Cs) {
+        av_log(s->avctx, AV_LOG_ERROR, "Invalid number of bits for XXCH speaker mask (%d)\n", s->xxch_mask_nbits);
+        return AVERROR_INVALIDDATA;
+    }
+
+    // Number of channel sets
+    xxch_nchsets = get_bits(&s->gb, 2) + 1;
+    if (xxch_nchsets > 1) {
+        avpriv_request_sample(s->avctx, "%d XXCH channel sets", xxch_nchsets);
+        return AVERROR_PATCHWELCOME;
+    }
+
+    // Channel set 0 data byte size
+    xxch_frame_size = get_bits(&s->gb, 14) + 1;
+
+    // Core loudspeaker activity mask
+    s->xxch_core_mask = get_bits_long(&s->gb, s->xxch_mask_nbits);
+
+    // Validate the core mask
+    mask = s->ch_mask;
+
+    if ((mask & DCA_SPEAKER_MASK_Ls) && (s->xxch_core_mask & DCA_SPEAKER_MASK_Lss))
+        mask = (mask & ~DCA_SPEAKER_MASK_Ls) | DCA_SPEAKER_MASK_Lss;
+
+    if ((mask & DCA_SPEAKER_MASK_Rs) && (s->xxch_core_mask & DCA_SPEAKER_MASK_Rss))
+        mask = (mask & ~DCA_SPEAKER_MASK_Rs) | DCA_SPEAKER_MASK_Rss;
+
+    if (mask != s->xxch_core_mask) {
+        av_log(s->avctx, AV_LOG_ERROR, "XXCH core speaker activity mask (%#x) disagrees with core (%#x)\n", s->xxch_core_mask, mask);
+        return AVERROR_INVALIDDATA;
+    }
+
+    // Reserved
+    // Byte align
+    // CRC16 of XXCH frame header
+    if (ff_dca_seek_bits(&s->gb, header_pos + header_size * 8)) {
+        av_log(s->avctx, AV_LOG_ERROR, "Read past end of XXCH frame header\n");
+        return AVERROR_INVALIDDATA;
+    }
+
+    // Parse XXCH channel set 0
+    if ((ret = parse_frame_data(s, HEADER_XXCH, s->nchannels)) < 0)
+        return ret;
+
+    if (ff_dca_seek_bits(&s->gb, header_pos + header_size * 8 + xxch_frame_size * 8)) {
+        av_log(s->avctx, AV_LOG_ERROR, "Read past end of XXCH channel set\n");
+        return AVERROR_INVALIDDATA;
+    }
+
+    return 0;
+}
+
+static int parse_xbr_subframe(DCACoreDecoder *s, int xbr_base_ch, int xbr_nchannels,
+                              int *xbr_nsubbands, int xbr_transition_mode, int sf, int *sub_pos)
+{
+    int     xbr_nabits[DCA_CHANNELS];
+    int     xbr_bit_allocation[DCA_CHANNELS][DCA_SUBBANDS];
+    int     xbr_scale_nbits[DCA_CHANNELS];
+    int32_t xbr_scale_factors[DCA_CHANNELS][DCA_SUBBANDS][2];
+    int     ssf, ch, band, ofs;
+
+    // Check number of subband samples in this subframe
+    if (*sub_pos + s->nsubsubframes[sf] * DCA_SUBBAND_SAMPLES > s->npcmblocks) {
+        av_log(s->avctx, AV_LOG_ERROR, "Subband sample buffer overflow\n");
+        return AVERROR_INVALIDDATA;
+    }
+
+    if (get_bits_left(&s->gb) < 0)
+        return AVERROR_INVALIDDATA;
+
+    // Number of bits for XBR bit allocation index
+    for (ch = xbr_base_ch; ch < xbr_nchannels; ch++)
+        xbr_nabits[ch] = get_bits(&s->gb, 2) + 2;
+
+    // XBR bit allocation index
+    for (ch = xbr_base_ch; ch < xbr_nchannels; ch++) {
+        for (band = 0; band < xbr_nsubbands[ch]; band++) {
+            xbr_bit_allocation[ch][band] = get_bits(&s->gb, xbr_nabits[ch]);
+            if (xbr_bit_allocation[ch][band] > DCA_ABITS_MAX) {
+                av_log(s->avctx, AV_LOG_ERROR, "Invalid XBR bit allocation index\n");
+                return AVERROR_INVALIDDATA;
+            }
+        }
+    }
+
+    // Number of bits for scale indices
+    for (ch = xbr_base_ch; ch < xbr_nchannels; ch++) {
+        xbr_scale_nbits[ch] = get_bits(&s->gb, 3);
+        if (!xbr_scale_nbits[ch]) {
+            av_log(s->avctx, AV_LOG_ERROR, "Invalid number of bits for XBR scale factor index\n");
+            return AVERROR_INVALIDDATA;
+        }
+    }
+
+    // XBR scale factors
+    for (ch = xbr_base_ch; ch < xbr_nchannels; ch++) {
+        const uint32_t *scale_table;
+        int scale_size;
+
+        // Select the root square table
+        if (s->scale_factor_sel[ch] > 5) {
+            scale_table = ff_dca_scale_factor_quant7;
+            scale_size = FF_ARRAY_ELEMS(ff_dca_scale_factor_quant7);
+        } else {
+            scale_table = ff_dca_scale_factor_quant6;
+            scale_size = FF_ARRAY_ELEMS(ff_dca_scale_factor_quant6);
+        }
+
+        // Parse scale factor indices and look up scale factors from the root
+        // square table
+        for (band = 0; band < xbr_nsubbands[ch]; band++) {
+            if (xbr_bit_allocation[ch][band]) {
+                int scale_index = get_bits(&s->gb, xbr_scale_nbits[ch]);
+                if (scale_index >= scale_size) {
+                    av_log(s->avctx, AV_LOG_ERROR, "Invalid XBR scale factor index\n");
+                    return AVERROR_INVALIDDATA;
+                }
+                xbr_scale_factors[ch][band][0] = scale_table[scale_index];
+                if (xbr_transition_mode && s->transition_mode[sf][ch][band]) {
+                    scale_index = get_bits(&s->gb, xbr_scale_nbits[ch]);
+                    if (scale_index >= scale_size) {
+                        av_log(s->avctx, AV_LOG_ERROR, "Invalid XBR scale factor index\n");
+                        return AVERROR_INVALIDDATA;
+                    }
+                    xbr_scale_factors[ch][band][1] = scale_table[scale_index];
+                }
+            }
+        }
+    }
+
+    // Audio data
+    for (ssf = 0, ofs = *sub_pos; ssf < s->nsubsubframes[sf]; ssf++) {
+        for (ch = xbr_base_ch; ch < xbr_nchannels; ch++) {
+            if (get_bits_left(&s->gb) < 0)
+                return AVERROR_INVALIDDATA;
+
+            for (band = 0; band < xbr_nsubbands[ch]; band++) {
+                int ret, trans_ssf, abits = xbr_bit_allocation[ch][band];
+                int32_t audio[DCA_SUBBAND_SAMPLES], step_size, scale;
+
+                // Extract bits from the bit stream
+                if (abits > 7) {
+                    // No further encoding
+                    get_array(&s->gb, audio, DCA_SUBBAND_SAMPLES, abits - 3);
+                } else if (abits > 0) {
+                    // Block codes
+                    if ((ret = parse_block_codes(s, audio, abits)) < 0)
+                        return ret;
+                } else {
+                    // No bits allocated
+                    continue;
+                }
+
+                // Look up quantization step size
+                step_size = ff_dca_lossless_quant[abits];
+
+                // Identify transient location
+                if (xbr_transition_mode)
+                    trans_ssf = s->transition_mode[sf][ch][band];
+                else
+                    trans_ssf = 0;
+
+                // Determine proper scale factor
+                if (trans_ssf == 0 || ssf < trans_ssf)
+                    scale = xbr_scale_factors[ch][band][0];
+                else
+                    scale = xbr_scale_factors[ch][band][1];
+
+                dequantize(s->subband_samples[ch][band] + ofs,
+                           audio, step_size, scale, 1);
+            }
+        }
+
+        // DSYNC
+        if ((ssf == s->nsubsubframes[sf] - 1 || s->sync_ssf) && get_bits(&s->gb, 16) != 0xffff) {
+            av_log(s->avctx, AV_LOG_ERROR, "XBR-DSYNC check failed\n");
+            return AVERROR_INVALIDDATA;
+        }
+
+        ofs += DCA_SUBBAND_SAMPLES;
+    }
+
+    // Advance subband sample pointer for the next subframe
+    *sub_pos = ofs;
+    return 0;
+}
+
+static int parse_xbr_frame(DCACoreDecoder *s)
+{
+    int     xbr_frame_size[DCA_EXSS_CHSETS_MAX];
+    int     xbr_nchannels[DCA_EXSS_CHSETS_MAX];
+    int     xbr_nsubbands[DCA_EXSS_CHSETS_MAX * DCA_EXSS_CHANNELS_MAX];
+    int     xbr_nchsets, xbr_transition_mode, xbr_band_nbits, xbr_base_ch;
+    int     i, ch1, ch2, ret, header_size, header_pos = get_bits_count(&s->gb);
+
+    // XBR sync word
+    if (get_bits_long(&s->gb, 32) != DCA_SYNCWORD_XBR) {
+        av_log(s->avctx, AV_LOG_ERROR, "Invalid XBR sync word\n");
+        return AVERROR_INVALIDDATA;
+    }
+
+    // XBR frame header length
+    header_size = get_bits(&s->gb, 6) + 1;
+
+    // Check XBR frame header CRC
+    if ((s->avctx->err_recognition & (AV_EF_CRCCHECK | AV_EF_CAREFUL))
+        && ff_dca_check_crc(&s->gb, header_pos + 32, header_pos + header_size * 8)) {
+        av_log(s->avctx, AV_LOG_ERROR, "Invalid XBR frame header checksum\n");
+        return AVERROR_INVALIDDATA;
+    }
+
+    // Number of channel sets
+    xbr_nchsets = get_bits(&s->gb, 2) + 1;
+
+    // Channel set data byte size
+    for (i = 0; i < xbr_nchsets; i++)
+        xbr_frame_size[i] = get_bits(&s->gb, 14) + 1;
+
+    // Transition mode flag
+    xbr_transition_mode = get_bits1(&s->gb);
+
+    // Channel set headers
+    for (i = 0, ch2 = 0; i < xbr_nchsets; i++) {
+        xbr_nchannels[i] = get_bits(&s->gb, 3) + 1;
+        xbr_band_nbits = get_bits(&s->gb, 2) + 5;
+        for (ch1 = 0; ch1 < xbr_nchannels[i]; ch1++, ch2++) {
+            xbr_nsubbands[ch2] = get_bits(&s->gb, xbr_band_nbits) + 1;
+            if (xbr_nsubbands[ch2] > DCA_SUBBANDS) {
+                av_log(s->avctx, AV_LOG_ERROR, "Invalid number of active XBR subbands (%d)\n", xbr_nsubbands[ch2]);
+                return AVERROR_INVALIDDATA;
+            }
+        }
+    }
+
+    // Reserved
+    // Byte align
+    // CRC16 of XBR frame header
+    if (ff_dca_seek_bits(&s->gb, header_pos + header_size * 8)) {
+        av_log(s->avctx, AV_LOG_ERROR, "Read past end of XBR frame header\n");
+        return AVERROR_INVALIDDATA;
+    }
+
+    // Channel set data
+    for (i = 0, xbr_base_ch = 0; i < xbr_nchsets; i++) {
+        header_pos = get_bits_count(&s->gb);
+
+        if (xbr_base_ch + xbr_nchannels[i] <= s->nchannels) {
+            int sf, sub_pos;
+
+            for (sf = 0, sub_pos = 0; sf < s->nsubframes; sf++) {
+                if ((ret = parse_xbr_subframe(s, xbr_base_ch,
+                                              xbr_base_ch + xbr_nchannels[i],
+                                              xbr_nsubbands, xbr_transition_mode,
+                                              sf, &sub_pos)) < 0)
+                    return ret;
+            }
+        }
+
+        xbr_base_ch += xbr_nchannels[i];
+
+        if (ff_dca_seek_bits(&s->gb, header_pos + xbr_frame_size[i] * 8)) {
+            av_log(s->avctx, AV_LOG_ERROR, "Read past end of XBR channel set\n");
+            return AVERROR_INVALIDDATA;
+        }
+    }
+
+    return 0;
+}
+
+// Modified ISO/IEC 9899 linear congruential generator
+// Returns pseudorandom integer in range [-2^30, 2^30 - 1]
+static int rand_x96(DCACoreDecoder *s)
+{
+    s->x96_rand = 1103515245U * s->x96_rand + 12345U;
+    return (s->x96_rand & 0x7fffffff) - 0x40000000;
+}
+
+static int parse_x96_subframe_audio(DCACoreDecoder *s, int sf, int xch_base, int *sub_pos)
+{
+    int n, ssf, ch, band, ofs;
+
+    // Check number of subband samples in this subframe
+    int nsamples = s->nsubsubframes[sf] * DCA_SUBBAND_SAMPLES;
+    if (*sub_pos + nsamples > s->npcmblocks) {
+        av_log(s->avctx, AV_LOG_ERROR, "Subband sample buffer overflow\n");
+        return AVERROR_INVALIDDATA;
+    }
+
+    if (get_bits_left(&s->gb) < 0)
+        return AVERROR_INVALIDDATA;
+
+    // VQ encoded or unallocated subbands
+    for (ch = xch_base; ch < s->x96_nchannels; ch++) {
+        for (band = s->x96_subband_start; band < s->nsubbands[ch]; band++) {
+            // Get the sample pointer and scale factor
+            int32_t *samples = s->x96_subband_samples[ch][band] + *sub_pos;
+            int32_t scale    = s->scale_factors[ch][band >> 1][band & 1];
+
+            switch (s->bit_allocation[ch][band]) {
+            case 0: // No bits allocated for subband
+                if (scale <= 1)
+                    memset(samples, 0, nsamples * sizeof(int32_t));
+                else for (n = 0; n < nsamples; n++)
+                    // Generate scaled random samples
+                    samples[n] = mul31(rand_x96(s), scale);
+                break;
+
+            case 1: // VQ encoded subband
+                for (ssf = 0; ssf < (s->nsubsubframes[sf] + 1) / 2; ssf++) {
+                    // Extract the VQ address from the bit stream and look up
+                    // the VQ code book for up to 16 subband samples
+                    const int8_t *vq_samples = ff_dca_high_freq_vq[get_bits(&s->gb, 10)];
+                    // Scale and take the samples
+                    for (n = 0; n < FFMIN(nsamples - ssf * 16, 16); n++)
+                        *samples++ = clip23(vq_samples[n] * scale + (1 << 3) >> 4);
+                }
+                break;
+            }
+        }
+    }
+
+    // Audio data
+    for (ssf = 0, ofs = *sub_pos; ssf < s->nsubsubframes[sf]; ssf++) {
+        for (ch = xch_base; ch < s->x96_nchannels; ch++) {
+            if (get_bits_left(&s->gb) < 0)
+                return AVERROR_INVALIDDATA;
+
+            for (band = s->x96_subband_start; band < s->nsubbands[ch]; band++) {
+                int ret, abits = s->bit_allocation[ch][band] - 1;
+                int32_t audio[DCA_SUBBAND_SAMPLES], step_size, scale;
+
+                // Not VQ encoded or unallocated subbands
+                if (abits < 1)
+                    continue;
+
+                // Extract bits from the bit stream
+                if ((ret = extract_audio(s, audio, abits, ch)) < 0)
+                    return ret;
+
+                // Select quantization step size table and look up quantization
+                // step size
+                if (s->bit_rate == 3)
+                    step_size = ff_dca_lossless_quant[abits];
+                else
+                    step_size = ff_dca_lossy_quant[abits];
+
+                // Get the scale factor
+                scale = s->scale_factors[ch][band >> 1][band & 1];
+
+                dequantize(s->x96_subband_samples[ch][band] + ofs,
+                           audio, step_size, scale, 0);
+            }
+        }
+
+        // DSYNC
+        if ((ssf == s->nsubsubframes[sf] - 1 || s->sync_ssf) && get_bits(&s->gb, 16) != 0xffff) {
+            av_log(s->avctx, AV_LOG_ERROR, "X96-DSYNC check failed\n");
+            return AVERROR_INVALIDDATA;
+        }
+
+        ofs += DCA_SUBBAND_SAMPLES;
+    }
+
+    // Inverse ADPCM
+    for (ch = xch_base; ch < s->x96_nchannels; ch++) {
+        inverse_adpcm(s->x96_subband_samples[ch], s->prediction_vq_index[ch],
+                      s->prediction_mode[ch], s->x96_subband_start, s->nsubbands[ch],
+                      *sub_pos, nsamples);
+    }
+
+    // Joint subband coding
+    for (ch = xch_base; ch < s->x96_nchannels; ch++) {
+        int src_ch = s->joint_intensity_index[ch] - 1;
+        if (src_ch >= 0) {
+            s->dcadsp->decode_joint(s->x96_subband_samples[ch], s->x96_subband_samples[src_ch],
+                                    s->joint_scale_factors[ch], s->nsubbands[ch],
+                                    s->nsubbands[src_ch], *sub_pos, nsamples);
+        }
+    }
+
+    // Advance subband sample pointer for the next subframe
+    *sub_pos = ofs;
+    return 0;
+}
+
+static void erase_x96_adpcm_history(DCACoreDecoder *s)
+{
+    int ch, band;
+
+    // Erase ADPCM history from previous frame if
+    // predictor history switch was disabled
+    for (ch = 0; ch < DCA_CHANNELS; ch++)
+        for (band = 0; band < DCA_SUBBANDS_X96; band++)
+            AV_ZERO128(s->x96_subband_samples[ch][band] - DCA_ADPCM_COEFFS);
+}
+
+static int alloc_x96_sample_buffer(DCACoreDecoder *s)
+{
+    int nchsamples = DCA_ADPCM_COEFFS + s->npcmblocks;
+    int nframesamples = nchsamples * DCA_CHANNELS * DCA_SUBBANDS_X96;
+    unsigned int size = s->x96_subband_size;
+    int ch, band;
+
+    // Reallocate subband sample buffer
+    av_fast_mallocz(&s->x96_subband_buffer, &s->x96_subband_size,
+                    nframesamples * sizeof(int32_t));
+    if (!s->x96_subband_buffer)
+        return AVERROR(ENOMEM);
+
+    if (size != s->x96_subband_size) {
+        for (ch = 0; ch < DCA_CHANNELS; ch++)
+            for (band = 0; band < DCA_SUBBANDS_X96; band++)
+                s->x96_subband_samples[ch][band] = s->x96_subband_buffer +
+                    (ch * DCA_SUBBANDS_X96 + band) * nchsamples + DCA_ADPCM_COEFFS;
+    }
+
+    if (!s->predictor_history)
+        erase_x96_adpcm_history(s);
+
+    return 0;
+}
+
+static int parse_x96_subframe_header(DCACoreDecoder *s, int xch_base)
+{
+    int ch, band, ret;
+
+    if (get_bits_left(&s->gb) < 0)
+        return AVERROR_INVALIDDATA;
+
+    // Prediction mode
+    for (ch = xch_base; ch < s->x96_nchannels; ch++)
+        for (band = s->x96_subband_start; band < s->nsubbands[ch]; band++)
+            s->prediction_mode[ch][band] = get_bits1(&s->gb);
+
+    // Prediction coefficients VQ address
+    for (ch = xch_base; ch < s->x96_nchannels; ch++)
+        for (band = s->x96_subband_start; band < s->nsubbands[ch]; band++)
+            if (s->prediction_mode[ch][band])
+                s->prediction_vq_index[ch][band] = get_bits(&s->gb, 12);
+
+    // Bit allocation index
+    for (ch = xch_base; ch < s->x96_nchannels; ch++) {
+        int sel = s->bit_allocation_sel[ch];
+        int abits = 0;
+
+        for (band = s->x96_subband_start; band < s->nsubbands[ch]; band++) {
+            // If Huffman code was used, the difference of abits was encoded
+            if (sel < 7)
+                abits += get_vlc(&s->gb, &vlc_quant_index[5 + 2 * s->x96_high_res], sel);
+            else
+                abits = get_bits(&s->gb, 3 + s->x96_high_res);
+
+            if (abits < 0 || abits > 7 + 8 * s->x96_high_res) {
+                av_log(s->avctx, AV_LOG_ERROR, "Invalid X96 bit allocation index\n");
+                return AVERROR_INVALIDDATA;
+            }
+
+            s->bit_allocation[ch][band] = abits;
+        }
+    }
+
+    // Scale factors
+    for (ch = xch_base; ch < s->x96_nchannels; ch++) {
+        int sel = s->scale_factor_sel[ch];
+        int scale_index = 0;
+
+        // Extract scales for subbands which are transmitted even for
+        // unallocated subbands
+        for (band = s->x96_subband_start; band < s->nsubbands[ch]; band++) {
+            if ((ret = parse_scale(s, &scale_index, sel)) < 0)
+                return ret;
+            s->scale_factors[ch][band >> 1][band & 1] = ret;
+        }
+    }
+
+    // Joint subband codebook select
+    for (ch = xch_base; ch < s->x96_nchannels; ch++) {
+        if (s->joint_intensity_index[ch]) {
+            s->joint_scale_sel[ch] = get_bits(&s->gb, 3);
+            if (s->joint_scale_sel[ch] == 7) {
+                av_log(s->avctx, AV_LOG_ERROR, "Invalid X96 joint scale factor code book\n");
+                return AVERROR_INVALIDDATA;
+            }
+        }
+    }
+
+    // Scale factors for joint subband coding
+    for (ch = xch_base; ch < s->x96_nchannels; ch++) {
+        int src_ch = s->joint_intensity_index[ch] - 1;
+        if (src_ch >= 0) {
+            int sel = s->joint_scale_sel[ch];
+            for (band = s->nsubbands[ch]; band < s->nsubbands[src_ch]; band++) {
+                if ((ret = parse_joint_scale(s, sel)) < 0)
+                    return ret;
+                s->joint_scale_factors[ch][band] = ret;
+            }
+        }
+    }
+
+    // Side information CRC check word
+    if (s->crc_present)
+        skip_bits(&s->gb, 16);
+
+    return 0;
+}
+
+static int parse_x96_coding_header(DCACoreDecoder *s, int exss, int xch_base)
+{
+    int n, ch, header_size = 0, header_pos = get_bits_count(&s->gb);
+
+    if (get_bits_left(&s->gb) < 0)
+        return AVERROR_INVALIDDATA;
+
+    if (exss) {
+        // Channel set header length
+        header_size = get_bits(&s->gb, 7) + 1;
+
+        // Check CRC
+        if (s->x96_crc_present
+            && (s->avctx->err_recognition & (AV_EF_CRCCHECK | AV_EF_CAREFUL))
+            && ff_dca_check_crc(&s->gb, header_pos, header_pos + header_size * 8)) {
+            av_log(s->avctx, AV_LOG_ERROR, "Invalid X96 channel set header checksum\n");
+            return AVERROR_INVALIDDATA;
+        }
+    }
+
+    // High resolution flag
+    s->x96_high_res = get_bits1(&s->gb);
+
+    // First encoded subband
+    if (s->x96_rev_no < 8) {
+        s->x96_subband_start = get_bits(&s->gb, 5);
+        if (s->x96_subband_start > 27) {
+            av_log(s->avctx, AV_LOG_ERROR, "Invalid X96 subband start index (%d)\n", s->x96_subband_start);
+            return AVERROR_INVALIDDATA;
+        }
+    } else {
+        s->x96_subband_start = DCA_SUBBANDS;
+    }
+
+    // Subband activity count
+    for (ch = xch_base; ch < s->x96_nchannels; ch++) {
+        s->nsubbands[ch] = get_bits(&s->gb, 6) + 1;
+        if (s->nsubbands[ch] < DCA_SUBBANDS) {
+            av_log(s->avctx, AV_LOG_ERROR, "Invalid X96 subband activity count (%d)\n", s->nsubbands[ch]);
+            return AVERROR_INVALIDDATA;
+        }
+    }
+
+    // Joint intensity coding index
+    for (ch = xch_base; ch < s->x96_nchannels; ch++) {
+        if ((n = get_bits(&s->gb, 3)) && xch_base)
+            n += xch_base - 1;
+        if (n > s->x96_nchannels) {
+            av_log(s->avctx, AV_LOG_ERROR, "Invalid X96 joint intensity coding index\n");
+            return AVERROR_INVALIDDATA;
+        }
+        s->joint_intensity_index[ch] = n;
+    }
+
+    // Scale factor code book
+    for (ch = xch_base; ch < s->x96_nchannels; ch++) {
+        s->scale_factor_sel[ch] = get_bits(&s->gb, 3);
+        if (s->scale_factor_sel[ch] >= 6) {
+            av_log(s->avctx, AV_LOG_ERROR, "Invalid X96 scale factor code book\n");
+            return AVERROR_INVALIDDATA;
+        }
+    }
+
+    // Bit allocation quantizer select
+    for (ch = xch_base; ch < s->x96_nchannels; ch++)
+        s->bit_allocation_sel[ch] = get_bits(&s->gb, 3);
+
+    // Quantization index codebook select
+    for (n = 0; n < 6 + 4 * s->x96_high_res; n++)
+        for (ch = xch_base; ch < s->x96_nchannels; ch++)
+            s->quant_index_sel[ch][n] = get_bits(&s->gb, quant_index_sel_nbits[n]);
+
+    if (exss) {
+        // Reserved
+        // Byte align
+        // CRC16 of channel set header
+        if (ff_dca_seek_bits(&s->gb, header_pos + header_size * 8)) {
+            av_log(s->avctx, AV_LOG_ERROR, "Read past end of X96 channel set header\n");
+            return AVERROR_INVALIDDATA;
+        }
+    } else {
+        if (s->crc_present)
+            skip_bits(&s->gb, 16);
+    }
+
+    return 0;
+}
+
+static int parse_x96_frame_data(DCACoreDecoder *s, int exss, int xch_base)
+{
+    int sf, ch, ret, band, sub_pos;
+
+    if ((ret = parse_x96_coding_header(s, exss, xch_base)) < 0)
+        return ret;
+
+    for (sf = 0, sub_pos = 0; sf < s->nsubframes; sf++) {
+        if ((ret = parse_x96_subframe_header(s, xch_base)) < 0)
+            return ret;
+        if ((ret = parse_x96_subframe_audio(s, sf, xch_base, &sub_pos)) < 0)
+            return ret;
+    }
+
+    for (ch = xch_base; ch < s->x96_nchannels; ch++) {
+        // Determine number of active subbands for this channel
+        int nsubbands = s->nsubbands[ch];
+        if (s->joint_intensity_index[ch])
+            nsubbands = FFMAX(nsubbands, s->nsubbands[s->joint_intensity_index[ch] - 1]);
+
+        // Update history for ADPCM and clear inactive subbands
+        for (band = 0; band < DCA_SUBBANDS_X96; band++) {
+            int32_t *samples = s->x96_subband_samples[ch][band] - DCA_ADPCM_COEFFS;
+            if (band >= s->x96_subband_start && band < nsubbands)
+                AV_COPY128(samples, samples + s->npcmblocks);
+            else
+                memset(samples, 0, (DCA_ADPCM_COEFFS + s->npcmblocks) * sizeof(int32_t));
+        }
+    }
+
+    return 0;
+}
+
+static int parse_x96_frame(DCACoreDecoder *s)
+{
+    int ret;
+
+    // Revision number
+    s->x96_rev_no = get_bits(&s->gb, 4);
+    if (s->x96_rev_no < 1 || s->x96_rev_no > 8) {
+        av_log(s->avctx, AV_LOG_ERROR, "Invalid X96 revision (%d)\n", s->x96_rev_no);
+        return AVERROR_INVALIDDATA;
+    }
+
+    s->x96_crc_present = 0;
+    s->x96_nchannels = s->nchannels;
+
+    if ((ret = alloc_x96_sample_buffer(s)) < 0)
+        return ret;
+
+    if ((ret = parse_x96_frame_data(s, 0, 0)) < 0)
+        return ret;
+
+    // Seek to the end of core frame
+    if (ff_dca_seek_bits(&s->gb, s->frame_size * 8)) {
+        av_log(s->avctx, AV_LOG_ERROR, "Read past end of X96 frame\n");
+        return AVERROR_INVALIDDATA;
+    }
+
+    return 0;
+}
+
+static int parse_x96_frame_exss(DCACoreDecoder *s)
+{
+    int     x96_frame_size[DCA_EXSS_CHSETS_MAX];
+    int     x96_nchannels[DCA_EXSS_CHSETS_MAX];
+    int     x96_nchsets, x96_base_ch;
+    int     i, ret, header_size, header_pos = get_bits_count(&s->gb);
+
+    // X96 sync word
+    if (get_bits_long(&s->gb, 32) != DCA_SYNCWORD_X96) {
+        av_log(s->avctx, AV_LOG_ERROR, "Invalid X96 sync word\n");
+        return AVERROR_INVALIDDATA;
+    }
+
+    // X96 frame header length
+    header_size = get_bits(&s->gb, 6) + 1;
+
+    // Check X96 frame header CRC
+    if ((s->avctx->err_recognition & (AV_EF_CRCCHECK | AV_EF_CAREFUL))
+        && ff_dca_check_crc(&s->gb, header_pos + 32, header_pos + header_size * 8)) {
+        av_log(s->avctx, AV_LOG_ERROR, "Invalid X96 frame header checksum\n");
+        return AVERROR_INVALIDDATA;
+    }
+
+    // Revision number
+    s->x96_rev_no = get_bits(&s->gb, 4);
+    if (s->x96_rev_no < 1 || s->x96_rev_no > 8) {
+        av_log(s->avctx, AV_LOG_ERROR, "Invalid X96 revision (%d)\n", s->x96_rev_no);
+        return AVERROR_INVALIDDATA;
+    }
+
+    // CRC presence flag for channel set header
+    s->x96_crc_present = get_bits1(&s->gb);
+
+    // Number of channel sets
+    x96_nchsets = get_bits(&s->gb, 2) + 1;
+
+    // Channel set data byte size
+    for (i = 0; i < x96_nchsets; i++)
+        x96_frame_size[i] = get_bits(&s->gb, 12) + 1;
+
+    // Number of channels in channel set
+    for (i = 0; i < x96_nchsets; i++)
+        x96_nchannels[i] = get_bits(&s->gb, 3) + 1;
+
+    // Reserved
+    // Byte align
+    // CRC16 of X96 frame header
+    if (ff_dca_seek_bits(&s->gb, header_pos + header_size * 8)) {
+        av_log(s->avctx, AV_LOG_ERROR, "Read past end of X96 frame header\n");
+        return AVERROR_INVALIDDATA;
+    }
+
+    if ((ret = alloc_x96_sample_buffer(s)) < 0)
+        return ret;
+
+    // Channel set data
+    for (i = 0, x96_base_ch = 0; i < x96_nchsets; i++) {
+        header_pos = get_bits_count(&s->gb);
+
+        if (x96_base_ch + x96_nchannels[i] <= s->nchannels) {
+            s->x96_nchannels = x96_base_ch + x96_nchannels[i];
+            if ((ret = parse_x96_frame_data(s, 1, x96_base_ch)) < 0)
+                return ret;
+        }
+
+        x96_base_ch += x96_nchannels[i];
+
+        if (ff_dca_seek_bits(&s->gb, header_pos + x96_frame_size[i] * 8)) {
+            av_log(s->avctx, AV_LOG_ERROR, "Read past end of X96 channel set\n");
+            return AVERROR_INVALIDDATA;
+        }
+    }
+
+    return 0;
+}
+
+static int parse_aux_data(DCACoreDecoder *s)
+{
+    int aux_pos;
+
+    if (get_bits_left(&s->gb) < 0)
+        return AVERROR_INVALIDDATA;
+
+    // Auxiliary data byte count (can't be trusted)
+    skip_bits(&s->gb, 6);
+
+    // 4-byte align
+    skip_bits_long(&s->gb, -get_bits_count(&s->gb) & 31);
+
+    // Auxiliary data sync word
+    if (get_bits_long(&s->gb, 32) != DCA_SYNCWORD_REV1AUX) {
+        av_log(s->avctx, AV_LOG_ERROR, "Invalid auxiliary data sync word\n");
+        return AVERROR_INVALIDDATA;
+    }
+
+    aux_pos = get_bits_count(&s->gb);
+
+    // Auxiliary decode time stamp flag
+    if (get_bits1(&s->gb))
+        skip_bits_long(&s->gb, 47);
+
+    // Auxiliary dynamic downmix flag
+    if (s->prim_dmix_embedded = get_bits1(&s->gb)) {
+        int i, m, n;
+
+        // Auxiliary primary channel downmix type
+        s->prim_dmix_type = get_bits(&s->gb, 3);
+        if (s->prim_dmix_type >= DCA_DMIX_TYPE_COUNT) {
+            av_log(s->avctx, AV_LOG_ERROR, "Invalid primary channel set downmix type\n");
+            return AVERROR_INVALIDDATA;
+        }
+
+        // Size of downmix coefficients matrix
+        m = ff_dca_dmix_primary_nch[s->prim_dmix_type];
+        n = ff_dca_channels[s->audio_mode] + !!s->lfe_present;
+
+        // Dynamic downmix code coefficients
+        for (i = 0; i < m * n; i++) {
+            int code = get_bits(&s->gb, 9);
+            int sign = (code >> 8) - 1;
+            unsigned int index = code & 0xff;
+            if (index >= FF_DCA_DMIXTABLE_SIZE) {
+                av_log(s->avctx, AV_LOG_ERROR, "Invalid downmix coefficient index\n");
+                return AVERROR_INVALIDDATA;
+            }
+            s->prim_dmix_coeff[i] = (ff_dca_dmixtable[index] ^ sign) - sign;
+        }
+    }
+
+    // Byte align
+    skip_bits(&s->gb, -get_bits_count(&s->gb) & 7);
+
+    // CRC16 of auxiliary data
+    skip_bits(&s->gb, 16);
+
+    // Check CRC
+    if ((s->avctx->err_recognition & (AV_EF_CRCCHECK | AV_EF_CAREFUL))
+        && ff_dca_check_crc(&s->gb, aux_pos, get_bits_count(&s->gb))) {
+        av_log(s->avctx, AV_LOG_ERROR, "Invalid auxiliary data checksum\n");
+        return AVERROR_INVALIDDATA;
+    }
+
+    return 0;
+}
+
+static int parse_optional_info(DCACoreDecoder *s)
+{
+    DCAContext *dca = s->avctx->priv_data;
+    int ret = -1;
+
+    // Time code stamp
+    if (s->ts_present)
+        skip_bits_long(&s->gb, 32);
+
+    // Auxiliary data
+    if (s->aux_present && (ret = parse_aux_data(s)) < 0
+        && (s->avctx->err_recognition & AV_EF_EXPLODE))
+        return ret;
+
+    if (ret < 0)
+        s->prim_dmix_embedded = 0;
+
+    // Core extensions
+    if (s->ext_audio_present && !dca->core_only) {
+        int sync_pos = FFMIN(s->frame_size / 4, s->gb.size_in_bits / 32) - 1;
+        int last_pos = get_bits_count(&s->gb) / 32;
+        int size, dist;
+
+        // Search for extension sync words aligned on 4-byte boundary. Search
+        // must be done backwards from the end of core frame to work around
+        // sync word aliasing issues.
+        switch (s->ext_audio_type) {
+        case EXT_AUDIO_XCH:
+            if (dca->request_channel_layout)
+                break;
+
+            // The distance between XCH sync word and end of the core frame
+            // must be equal to XCH frame size. Off by one error is allowed for
+            // compatibility with legacy bitstreams. Minimum XCH frame size is
+            // 96 bytes. AMODE and PCHS are further checked to reduce
+            // probability of alias sync detection.
+            for (; sync_pos >= last_pos; sync_pos--) {
+                if (AV_RB32(s->gb.buffer + sync_pos * 4) == DCA_SYNCWORD_XCH) {
+                    s->gb.index = (sync_pos + 1) * 32;
+                    size = get_bits(&s->gb, 10) + 1;
+                    dist = s->frame_size - sync_pos * 4;
+                    if (size >= 96
+                        && (size == dist || size - 1 == dist)
+                        && get_bits(&s->gb, 7) == 0x08) {
+                        s->xch_pos = get_bits_count(&s->gb);
+                        break;
+                    }
+                }
+            }
+
+            if (s->avctx->err_recognition & AV_EF_EXPLODE) {
+                av_log(s->avctx, AV_LOG_ERROR, "XCH sync word not found\n");
+                return AVERROR_INVALIDDATA;
+            }
+            break;
+
+        case EXT_AUDIO_X96:
+            // The distance between X96 sync word and end of the core frame
+            // must be equal to X96 frame size. Minimum X96 frame size is 96
+            // bytes.
+            for (; sync_pos >= last_pos; sync_pos--) {
+                if (AV_RB32(s->gb.buffer + sync_pos * 4) == DCA_SYNCWORD_X96) {
+                    s->gb.index = (sync_pos + 1) * 32;
+                    size = get_bits(&s->gb, 12) + 1;
+                    dist = s->frame_size - sync_pos * 4;
+                    if (size >= 96 && size == dist) {
+                        s->x96_pos = get_bits_count(&s->gb);
+                        break;
+                    }
+                }
+            }
+
+            if (s->avctx->err_recognition & AV_EF_EXPLODE) {
+                av_log(s->avctx, AV_LOG_ERROR, "X96 sync word not found\n");
+                return AVERROR_INVALIDDATA;
+            }
+            break;
+
+        case EXT_AUDIO_XXCH:
+            if (dca->request_channel_layout)
+                break;
+
+            // XXCH frame header CRC must be valid. Minimum XXCH frame header
+            // size is 11 bytes.
+            for (; sync_pos >= last_pos; sync_pos--) {
+                if (AV_RB32(s->gb.buffer + sync_pos * 4) == DCA_SYNCWORD_XXCH) {
+                    s->gb.index = (sync_pos + 1) * 32;
+                    size = get_bits(&s->gb, 6) + 1;
+                    if (size >= 11 &&
+                        !ff_dca_check_crc(&s->gb, (sync_pos + 1) * 32,
+                                          sync_pos * 32 + size * 8)) {
+                        s->xxch_pos = sync_pos * 32;
+                        break;
+                    }
+                }
+            }
+
+            if (s->avctx->err_recognition & AV_EF_EXPLODE) {
+                av_log(s->avctx, AV_LOG_ERROR, "XXCH sync word not found\n");
+                return AVERROR_INVALIDDATA;
+            }
+            break;
+        }
+    }
+
+    return 0;
+}
+
+int ff_dca_core_parse(DCACoreDecoder *s, uint8_t *data, int size)
+{
+    int ret;
+
+    s->ext_audio_mask = 0;
+    s->xch_pos = s->xxch_pos = s->x96_pos = 0;
+
+    if ((ret = init_get_bits8(&s->gb, data, size)) < 0)
+        return ret;
+
+    skip_bits_long(&s->gb, 32);
+    if ((ret = parse_frame_header(s)) < 0)
+        return ret;
+    if ((ret = alloc_sample_buffer(s)) < 0)
+        return ret;
+    if ((ret = parse_frame_data(s, HEADER_CORE, 0)) < 0)
+        return ret;
+    if ((ret = parse_optional_info(s)) < 0)
+        return ret;
+
+    // Workaround for DTS in WAV
+    if (s->frame_size > size && s->frame_size < size + 4) {
+        av_log(s->avctx, AV_LOG_DEBUG, "Working around excessive core frame size (%d > %d)\n", s->frame_size, size);
+        s->frame_size = size;
+    }
+
+    if (ff_dca_seek_bits(&s->gb, s->frame_size * 8)) {
+        av_log(s->avctx, AV_LOG_ERROR, "Read past end of core frame\n");
+        return AVERROR_INVALIDDATA;
+    }
+
+    return 0;
+}
+
+int ff_dca_core_parse_exss(DCACoreDecoder *s, uint8_t *data, DCAExssAsset *asset)
+{
+    AVCodecContext *avctx = s->avctx;
+    DCAContext *dca = avctx->priv_data;
+    GetBitContext gb = s->gb;
+    int exss_mask = asset ? asset->extension_mask : 0;
+    int ret = 0, ext = 0;
+
+    // Parse (X)XCH unless downmixing
+    if (!dca->request_channel_layout) {
+        if (exss_mask & DCA_EXSS_XXCH) {
+            if ((ret = init_get_bits8(&s->gb, data + asset->xxch_offset, asset->xxch_size)) < 0)
+                return ret;
+            ret = parse_xxch_frame(s);
+            ext = DCA_EXSS_XXCH;
+        } else if (s->xxch_pos) {
+            s->gb.index = s->xxch_pos;
+            ret = parse_xxch_frame(s);
+            ext = DCA_CSS_XXCH;
+        } else if (s->xch_pos) {
+            s->gb.index = s->xch_pos;
+            ret = parse_xch_frame(s);
+            ext = DCA_CSS_XCH;
+        }
+
+        // Revert to primary channel set in case (X)XCH parsing fails
+        if (ret < 0) {
+            if (avctx->err_recognition & AV_EF_EXPLODE)
+                return ret;
+            s->nchannels = ff_dca_channels[s->audio_mode];
+            s->ch_mask = audio_mode_ch_mask[s->audio_mode];
+            if (s->lfe_present)
+                s->ch_mask |= DCA_SPEAKER_MASK_LFE1;
+        } else {
+            s->ext_audio_mask |= ext;
+        }
+    }
+
+    // Parse XBR
+    if (exss_mask & DCA_EXSS_XBR) {
+        if ((ret = init_get_bits8(&s->gb, data + asset->xbr_offset, asset->xbr_size)) < 0)
+            return ret;
+        if ((ret = parse_xbr_frame(s)) < 0) {
+            if (avctx->err_recognition & AV_EF_EXPLODE)
+                return ret;
+        } else {
+            s->ext_audio_mask |= DCA_EXSS_XBR;
+        }
+    }
+
+    // Parse X96 unless decoding XLL
+    if (!(dca->packet & DCA_PACKET_XLL)) {
+        if (exss_mask & DCA_EXSS_X96) {
+            if ((ret = init_get_bits8(&s->gb, data + asset->x96_offset, asset->x96_size)) < 0)
+                return ret;
+            if ((ret = parse_x96_frame_exss(s)) < 0) {
+                if (ret == AVERROR(ENOMEM) || (avctx->err_recognition & AV_EF_EXPLODE))
+                    return ret;
+            } else {
+                s->ext_audio_mask |= DCA_EXSS_X96;
+            }
+        } else if (s->x96_pos) {
+            s->gb = gb;
+            s->gb.index = s->x96_pos;
+            if ((ret = parse_x96_frame(s)) < 0) {
+                if (ret == AVERROR(ENOMEM) || (avctx->err_recognition & AV_EF_EXPLODE))
+                    return ret;
+            } else {
+                s->ext_audio_mask |= DCA_CSS_X96;
+            }
+        }
+    }
+
+    return 0;
+}
+
+static int map_prm_ch_to_spkr(DCACoreDecoder *s, int ch)
+{
+    int pos, spkr;
+
+    // Try to map this channel to core first
+    pos = ff_dca_channels[s->audio_mode];
+    if (ch < pos) {
+        spkr = prm_ch_to_spkr_map[s->audio_mode][ch];
+        if (s->ext_audio_mask & (DCA_CSS_XXCH | DCA_EXSS_XXCH)) {
+            if (s->xxch_core_mask & (1U << spkr))
+                return spkr;
+            if (spkr == DCA_SPEAKER_Ls && (s->xxch_core_mask & DCA_SPEAKER_MASK_Lss))
+                return DCA_SPEAKER_Lss;
+            if (spkr == DCA_SPEAKER_Rs && (s->xxch_core_mask & DCA_SPEAKER_MASK_Rss))
+                return DCA_SPEAKER_Rss;
+            return -1;
+        }
+        return spkr;
+    }
+
+    // Then XCH
+    if ((s->ext_audio_mask & DCA_CSS_XCH) && ch == pos)
+        return DCA_SPEAKER_Cs;
+
+    // Then XXCH
+    if (s->ext_audio_mask & (DCA_CSS_XXCH | DCA_EXSS_XXCH)) {
+        for (spkr = DCA_SPEAKER_Cs; spkr < s->xxch_mask_nbits; spkr++)
+            if (s->xxch_spkr_mask & (1U << spkr))
+                if (pos++ == ch)
+                    return spkr;
+    }
+
+    // No mapping
+    return -1;
+}
+
+static void erase_dsp_history(DCACoreDecoder *s)
+{
+    memset(s->dcadsp_data, 0, sizeof(s->dcadsp_data));
+    s->output_history_lfe_fixed = 0;
+    s->output_history_lfe_float = 0;
+}
+
+static void set_filter_mode(DCACoreDecoder *s, int mode)
+{
+    if (s->filter_mode != mode) {
+        erase_dsp_history(s);
+        s->filter_mode = mode;
+    }
+}
+
+int ff_dca_core_filter_fixed(DCACoreDecoder *s, int x96_synth)
+{
+    int n, ch, spkr, nsamples, x96_nchannels = 0;
+    const int32_t *filter_coeff;
+    int32_t *ptr;
+
+    // Externally set x96_synth flag implies that X96 synthesis should be
+    // enabled, yet actual X96 subband data should be discarded. This is a
+    // special case for lossless residual decoder that ignores X96 data if
+    // present.
+    if (!x96_synth && (s->ext_audio_mask & (DCA_CSS_X96 | DCA_EXSS_X96))) {
+        x96_nchannels = s->x96_nchannels;
+        x96_synth = 1;
+    }
+    if (x96_synth < 0)
+        x96_synth = 0;
+
+    s->output_rate = s->sample_rate << x96_synth;
+    s->npcmsamples = nsamples = (s->npcmblocks * DCA_PCMBLOCK_SAMPLES) << x96_synth;
+
+    // Reallocate PCM output buffer
+    av_fast_malloc(&s->output_buffer, &s->output_size,
+                   nsamples * av_popcount(s->ch_mask) * sizeof(int32_t));
+    if (!s->output_buffer)
+        return AVERROR(ENOMEM);
+
+    ptr = (int32_t *)s->output_buffer;
+    for (spkr = 0; spkr < DCA_SPEAKER_COUNT; spkr++) {
+        if (s->ch_mask & (1U << spkr)) {
+            s->output_samples[spkr] = ptr;
+            ptr += nsamples;
+        } else {
+            s->output_samples[spkr] = NULL;
+        }
+    }
+
+    // Handle change of filtering mode
+    set_filter_mode(s, x96_synth | DCA_FILTER_MODE_FIXED);
+
+    // Select filter
+    if (x96_synth)
+        filter_coeff = ff_dca_fir_64bands_fixed;
+    else if (s->filter_perfect)
+        filter_coeff = ff_dca_fir_32bands_perfect_fixed;
+    else
+        filter_coeff = ff_dca_fir_32bands_nonperfect_fixed;
+
+    // Filter primary channels
+    for (ch = 0; ch < s->nchannels; ch++) {
+        // Map this primary channel to speaker
+        spkr = map_prm_ch_to_spkr(s, ch);
+        if (spkr < 0)
+            return AVERROR(EINVAL);
+
+        // Filter bank reconstruction
+        s->dcadsp->sub_qmf_fixed[x96_synth](
+            &s->synth,
+            &s->dcadct,
+            s->output_samples[spkr],
+            s->subband_samples[ch],
+            ch < x96_nchannels ? s->x96_subband_samples[ch] : NULL,
+            s->dcadsp_data[ch].u.fix.hist1,
+            &s->dcadsp_data[ch].offset,
+            s->dcadsp_data[ch].u.fix.hist2,
+            filter_coeff,
+            s->npcmblocks);
+    }
+
+    // Filter LFE channel
+    if (s->lfe_present) {
+        int32_t *samples = s->output_samples[DCA_SPEAKER_LFE1];
+        int nlfesamples = s->npcmblocks >> 1;
+
+        // Check LFF
+        if (s->lfe_present == LFE_FLAG_128) {
+            av_log(s->avctx, AV_LOG_ERROR, "Fixed point mode doesn't support LFF=1\n");
+            return AVERROR(EINVAL);
+        }
+
+        // Offset intermediate buffer for X96
+        if (x96_synth)
+            samples += nsamples / 2;
+
+        // Interpolate LFE channel
+        s->dcadsp->lfe_fir_fixed(samples, s->lfe_samples + DCA_LFE_HISTORY,
+                                 ff_dca_lfe_fir_64_fixed, s->npcmblocks);
+
+        if (x96_synth) {
+            // Filter 96 kHz oversampled LFE PCM to attenuate high frequency
+            // (47.6 - 48.0 kHz) components of interpolation image
+            s->dcadsp->lfe_x96_fixed(s->output_samples[DCA_SPEAKER_LFE1],
+                                     samples, &s->output_history_lfe_fixed,
+                                     nsamples / 2);
+
+        }
+
+        // Update LFE history
+        for (n = DCA_LFE_HISTORY - 1; n >= 0; n--)
+            s->lfe_samples[n] = s->lfe_samples[nlfesamples + n];
+    }
+
+    return 0;
+}
+
+static int filter_frame_fixed(DCACoreDecoder *s, AVFrame *frame)
+{
+    AVCodecContext *avctx = s->avctx;
+    DCAContext *dca = avctx->priv_data;
+    int i, n, ch, ret, spkr, nsamples;
+
+    // Don't filter twice when falling back from XLL
+    if (!(dca->packet & DCA_PACKET_XLL) && (ret = ff_dca_core_filter_fixed(s, 0)) < 0)
+        return ret;
+
+    avctx->sample_rate = s->output_rate;
+    avctx->sample_fmt = AV_SAMPLE_FMT_S32P;
+    avctx->bits_per_raw_sample = 24;
+
+    frame->nb_samples = nsamples = s->npcmsamples;
+    if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)
+        return ret;
+
+    // Undo embedded XCH downmix
+    if (s->es_format && (s->ext_audio_mask & DCA_CSS_XCH)
+        && s->audio_mode >= AMODE_2F2R) {
+        s->dcadsp->dmix_sub_xch(s->output_samples[DCA_SPEAKER_Ls],
+                                s->output_samples[DCA_SPEAKER_Rs],
+                                s->output_samples[DCA_SPEAKER_Cs],
+                                nsamples);
+
+    }
+
+    // Undo embedded XXCH downmix
+    if ((s->ext_audio_mask & (DCA_CSS_XXCH | DCA_EXSS_XXCH))
+        && s->xxch_dmix_embedded) {
+        int scale_inv   = s->xxch_dmix_scale_inv;
+        int *coeff_ptr  = s->xxch_dmix_coeff;
+        int xch_base    = ff_dca_channels[s->audio_mode];
+        av_assert1(s->nchannels - xch_base <= DCA_XXCH_CHANNELS_MAX);
+
+        // Undo embedded core downmix pre-scaling
+        for (spkr = 0; spkr < s->xxch_mask_nbits; spkr++) {
+            if (s->xxch_core_mask & (1U << spkr)) {
+                s->dcadsp->dmix_scale_inv(s->output_samples[spkr],
+                                          scale_inv, nsamples);
+            }
+        }
+
+        // Undo downmix
+        for (ch = xch_base; ch < s->nchannels; ch++) {
+            int src_spkr = map_prm_ch_to_spkr(s, ch);
+            if (src_spkr < 0)
+                return AVERROR(EINVAL);
+            for (spkr = 0; spkr < s->xxch_mask_nbits; spkr++) {
+                if (s->xxch_dmix_mask[ch - xch_base] & (1U << spkr)) {
+                    int coeff = mul16(*coeff_ptr++, scale_inv);
+                    if (coeff) {
+                        s->dcadsp->dmix_sub(s->output_samples[spkr    ],
+                                            s->output_samples[src_spkr],
+                                            coeff, nsamples);
+                    }
+                }
+            }
+        }
+    }
+
+    if (!(s->ext_audio_mask & (DCA_CSS_XXCH | DCA_CSS_XCH | DCA_EXSS_XXCH))) {
+        // Front sum/difference decoding
+        if ((s->sumdiff_front && s->audio_mode > AMODE_MONO)
+            || s->audio_mode == AMODE_STEREO_SUMDIFF) {
+            s->fixed_dsp->butterflies_fixed(s->output_samples[DCA_SPEAKER_L],
+                                            s->output_samples[DCA_SPEAKER_R],
+                                            nsamples);
+        }
+
+        // Surround sum/difference decoding
+        if (s->sumdiff_surround && s->audio_mode >= AMODE_2F2R) {
+            s->fixed_dsp->butterflies_fixed(s->output_samples[DCA_SPEAKER_Ls],
+                                            s->output_samples[DCA_SPEAKER_Rs],
+                                            nsamples);
+        }
+    }
+
+    // Downmix primary channel set to stereo
+    if (s->request_mask != s->ch_mask) {
+        ff_dca_downmix_to_stereo_fixed(s->dcadsp,
+                                       s->output_samples,
+                                       s->prim_dmix_coeff,
+                                       nsamples, s->ch_mask);
+    }
+
+    for (i = 0; i < avctx->channels; i++) {
+        int32_t *samples = s->output_samples[s->ch_remap[i]];
+        int32_t *plane = (int32_t *)frame->extended_data[i];
+        for (n = 0; n < nsamples; n++)
+            plane[n] = clip23(samples[n]) * (1 << 8);
+    }
+
+    return 0;
+}
+
+static int filter_frame_float(DCACoreDecoder *s, AVFrame *frame)
+{
+    AVCodecContext *avctx = s->avctx;
+    int x96_nchannels = 0, x96_synth = 0;
+    int i, n, ch, ret, spkr, nsamples, nchannels;
+    float *output_samples[DCA_SPEAKER_COUNT] = { NULL }, *ptr;
+    const float *filter_coeff;
+
+    if (s->ext_audio_mask & (DCA_CSS_X96 | DCA_EXSS_X96)) {
+        x96_nchannels = s->x96_nchannels;
+        x96_synth = 1;
+    }
+
+    avctx->sample_rate = s->sample_rate << x96_synth;
+    avctx->sample_fmt = AV_SAMPLE_FMT_FLTP;
+    avctx->bits_per_raw_sample = 0;
+
+    frame->nb_samples = nsamples = (s->npcmblocks * DCA_PCMBLOCK_SAMPLES) << x96_synth;
+    if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)
+        return ret;
+
+    // Build reverse speaker to channel mapping
+    for (i = 0; i < avctx->channels; i++)
+        output_samples[s->ch_remap[i]] = (float *)frame->extended_data[i];
+
+    // Allocate space for extra channels
+    nchannels = av_popcount(s->ch_mask) - avctx->channels;
+    if (nchannels > 0) {
+        av_fast_malloc(&s->output_buffer, &s->output_size,
+                       nsamples * nchannels * sizeof(float));
+        if (!s->output_buffer)
+            return AVERROR(ENOMEM);
+
+        ptr = (float *)s->output_buffer;
+        for (spkr = 0; spkr < DCA_SPEAKER_COUNT; spkr++) {
+            if (!(s->ch_mask & (1U << spkr)))
+                continue;
+            if (output_samples[spkr])
+                continue;
+            output_samples[spkr] = ptr;
+            ptr += nsamples;
+        }
+    }
+
+    // Handle change of filtering mode
+    set_filter_mode(s, x96_synth);
+
+    // Select filter
+    if (x96_synth)
+        filter_coeff = ff_dca_fir_64bands;
+    else if (s->filter_perfect)
+        filter_coeff = ff_dca_fir_32bands_perfect;
+    else
+        filter_coeff = ff_dca_fir_32bands_nonperfect;
+
+    // Filter primary channels
+    for (ch = 0; ch < s->nchannels; ch++) {
+        // Map this primary channel to speaker
+        spkr = map_prm_ch_to_spkr(s, ch);
+        if (spkr < 0)
+            return AVERROR(EINVAL);
+
+        // Filter bank reconstruction
+        s->dcadsp->sub_qmf_float[x96_synth](
+            &s->synth,
+            &s->imdct[x96_synth],
+            output_samples[spkr],
+            s->subband_samples[ch],
+            ch < x96_nchannels ? s->x96_subband_samples[ch] : NULL,
+            s->dcadsp_data[ch].u.flt.hist1,
+            &s->dcadsp_data[ch].offset,
+            s->dcadsp_data[ch].u.flt.hist2,
+            filter_coeff,
+            s->npcmblocks,
+            1.0f / (1 << (17 - x96_synth)));
+    }
+
+    // Filter LFE channel
+    if (s->lfe_present) {
+        int dec_select = (s->lfe_present == LFE_FLAG_128);
+        float *samples = output_samples[DCA_SPEAKER_LFE1];
+        int nlfesamples = s->npcmblocks >> (dec_select + 1);
+
+        // Offset intermediate buffer for X96
+        if (x96_synth)
+            samples += nsamples / 2;
+
+        // Select filter
+        if (dec_select)
+            filter_coeff = ff_dca_lfe_fir_128;
+        else
+            filter_coeff = ff_dca_lfe_fir_64;
+
+        // Interpolate LFE channel
+        s->dcadsp->lfe_fir_float[dec_select](
+            samples, s->lfe_samples + DCA_LFE_HISTORY,
+            filter_coeff, s->npcmblocks);
+
+        if (x96_synth) {
+            // Filter 96 kHz oversampled LFE PCM to attenuate high frequency
+            // (47.6 - 48.0 kHz) components of interpolation image
+            s->dcadsp->lfe_x96_float(output_samples[DCA_SPEAKER_LFE1],
+                                     samples, &s->output_history_lfe_float,
+                                     nsamples / 2);
+        }
+
+        // Update LFE history
+        for (n = DCA_LFE_HISTORY - 1; n >= 0; n--)
+            s->lfe_samples[n] = s->lfe_samples[nlfesamples + n];
+    }
+
+    // Undo embedded XCH downmix
+    if (s->es_format && (s->ext_audio_mask & DCA_CSS_XCH)
+        && s->audio_mode >= AMODE_2F2R) {
+        s->float_dsp->vector_fmac_scalar(output_samples[DCA_SPEAKER_Ls],
+                                         output_samples[DCA_SPEAKER_Cs],
+                                         -M_SQRT1_2, nsamples);
+        s->float_dsp->vector_fmac_scalar(output_samples[DCA_SPEAKER_Rs],
+                                         output_samples[DCA_SPEAKER_Cs],
+                                         -M_SQRT1_2, nsamples);
+    }
+
+    // Undo embedded XXCH downmix
+    if ((s->ext_audio_mask & (DCA_CSS_XXCH | DCA_EXSS_XXCH))
+        && s->xxch_dmix_embedded) {
+        float scale_inv = s->xxch_dmix_scale_inv * (1.0f / (1 << 16));
+        int *coeff_ptr  = s->xxch_dmix_coeff;
+        int xch_base    = ff_dca_channels[s->audio_mode];
+        av_assert1(s->nchannels - xch_base <= DCA_XXCH_CHANNELS_MAX);
+
+        // Undo downmix
+        for (ch = xch_base; ch < s->nchannels; ch++) {
+            int src_spkr = map_prm_ch_to_spkr(s, ch);
+            if (src_spkr < 0)
+                return AVERROR(EINVAL);
+            for (spkr = 0; spkr < s->xxch_mask_nbits; spkr++) {
+                if (s->xxch_dmix_mask[ch - xch_base] & (1U << spkr)) {
+                    int coeff = *coeff_ptr++;
+                    if (coeff) {
+                        s->float_dsp->vector_fmac_scalar(output_samples[    spkr],
+                                                         output_samples[src_spkr],
+                                                         coeff * (-1.0f / (1 << 15)),
+                                                         nsamples);
+                    }
+                }
+            }
+        }
+
+        // Undo embedded core downmix pre-scaling
+        for (spkr = 0; spkr < s->xxch_mask_nbits; spkr++) {
+            if (s->xxch_core_mask & (1U << spkr)) {
+                s->float_dsp->vector_fmul_scalar(output_samples[spkr],
+                                                 output_samples[spkr],
+                                                 scale_inv, nsamples);
+            }
+        }
+    }
+
+    if (!(s->ext_audio_mask & (DCA_CSS_XXCH | DCA_CSS_XCH | DCA_EXSS_XXCH))) {
+        // Front sum/difference decoding
+        if ((s->sumdiff_front && s->audio_mode > AMODE_MONO)
+            || s->audio_mode == AMODE_STEREO_SUMDIFF) {
+            s->float_dsp->butterflies_float(output_samples[DCA_SPEAKER_L],
+                                            output_samples[DCA_SPEAKER_R],
+                                            nsamples);
+        }
+
+        // Surround sum/difference decoding
+        if (s->sumdiff_surround && s->audio_mode >= AMODE_2F2R) {
+            s->float_dsp->butterflies_float(output_samples[DCA_SPEAKER_Ls],
+                                            output_samples[DCA_SPEAKER_Rs],
+                                            nsamples);
+        }
+    }
+
+    // Downmix primary channel set to stereo
+    if (s->request_mask != s->ch_mask) {
+        ff_dca_downmix_to_stereo_float(s->float_dsp, output_samples,
+                                       s->prim_dmix_coeff,
+                                       nsamples, s->ch_mask);
+    }
+
+    return 0;
+}
+
+int ff_dca_core_filter_frame(DCACoreDecoder *s, AVFrame *frame)
+{
+    AVCodecContext *avctx = s->avctx;
+    DCAContext *dca = avctx->priv_data;
+    DCAExssAsset *asset = &dca->exss.assets[0];
+    enum AVMatrixEncoding matrix_encoding;
+    int ret;
+
+    // Handle downmixing to stereo request
+    if (dca->request_channel_layout == DCA_SPEAKER_LAYOUT_STEREO
+        && s->audio_mode > AMODE_MONO && s->prim_dmix_embedded
+        && (s->prim_dmix_type == DCA_DMIX_TYPE_LoRo ||
+            s->prim_dmix_type == DCA_DMIX_TYPE_LtRt))
+        s->request_mask = DCA_SPEAKER_LAYOUT_STEREO;
+    else
+        s->request_mask = s->ch_mask;
+    if (!ff_dca_set_channel_layout(avctx, s->ch_remap, s->request_mask))
+        return AVERROR(EINVAL);
+
+    // Force fixed point mode when falling back from XLL
+    if ((avctx->flags & AV_CODEC_FLAG_BITEXACT) || ((dca->packet & DCA_PACKET_EXSS)
+                                                    && (asset->extension_mask & DCA_EXSS_XLL)))
+        ret = filter_frame_fixed(s, frame);
+    else
+        ret = filter_frame_float(s, frame);
+    if (ret < 0)
+        return ret;
+
+    // Set profile, bit rate, etc
+    if (s->ext_audio_mask & DCA_EXSS_MASK)
+        avctx->profile = FF_PROFILE_DTS_HD_HRA;
+    else if (s->ext_audio_mask & (DCA_CSS_XXCH | DCA_CSS_XCH))
+        avctx->profile = FF_PROFILE_DTS_ES;
+    else if (s->ext_audio_mask & DCA_CSS_X96)
+        avctx->profile = FF_PROFILE_DTS_96_24;
+    else
+        avctx->profile = FF_PROFILE_DTS;
+
+    if (s->bit_rate > 3 && !(s->ext_audio_mask & DCA_EXSS_MASK))
+        avctx->bit_rate = s->bit_rate;
+    else
+        avctx->bit_rate = 0;
+
+    if (s->audio_mode == AMODE_STEREO_TOTAL || (s->request_mask != s->ch_mask &&
+                                                s->prim_dmix_type == DCA_DMIX_TYPE_LtRt))
+        matrix_encoding = AV_MATRIX_ENCODING_DOLBY;
+    else
+        matrix_encoding = AV_MATRIX_ENCODING_NONE;
+    if ((ret = ff_side_data_update_matrix_encoding(frame, matrix_encoding)) < 0)
+        return ret;
+
+    return 0;
+}
+
+av_cold void ff_dca_core_flush(DCACoreDecoder *s)
+{
+    if (s->subband_buffer) {
+        erase_adpcm_history(s);
+        memset(s->lfe_samples, 0, DCA_LFE_HISTORY * sizeof(int32_t));
+    }
+
+    if (s->x96_subband_buffer)
+        erase_x96_adpcm_history(s);
+
+    erase_dsp_history(s);
+}
+
+av_cold int ff_dca_core_init(DCACoreDecoder *s)
+{
+    dca_init_vlcs();
+
+    if (!(s->float_dsp = avpriv_float_dsp_alloc(0)))
+        return -1;
+    if (!(s->fixed_dsp = avpriv_alloc_fixed_dsp(0)))
+        return -1;
+
+    ff_dcadct_init(&s->dcadct);
+    if (ff_mdct_init(&s->imdct[0], 6, 1, 1.0) < 0)
+        return -1;
+    if (ff_mdct_init(&s->imdct[1], 7, 1, 1.0) < 0)
+        return -1;
+    ff_synth_filter_init(&s->synth);
+
+    s->x96_rand = 1;
+    return 0;
+}
+
+av_cold void ff_dca_core_close(DCACoreDecoder *s)
+{
+    av_freep(&s->float_dsp);
+    av_freep(&s->fixed_dsp);
+
+    ff_mdct_end(&s->imdct[0]);
+    ff_mdct_end(&s->imdct[1]);
+
+    av_freep(&s->subband_buffer);
+    s->subband_size = 0;
+
+    av_freep(&s->x96_subband_buffer);
+    s->x96_subband_size = 0;
+
+    av_freep(&s->output_buffer);
+    s->output_size = 0;
+}
diff --git a/libavcodec/dca_core.h b/libavcodec/dca_core.h
new file mode 100644
index 0000000..112b72b
--- /dev/null
+++ b/libavcodec/dca_core.h
@@ -0,0 +1,206 @@
+/*
+ * Copyright (C) 2016 foo86
+ *
+ * This file is part of FFmpeg.
+ *
+ * FFmpeg is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * FFmpeg is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with FFmpeg; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#ifndef AVCODEC_DCA_CORE_H
+#define AVCODEC_DCA_CORE_H
+
+#include "libavutil/common.h"
+#include "libavutil/float_dsp.h"
+#include "libavutil/fixed_dsp.h"
+#include "libavutil/mem.h"
+
+#include "avcodec.h"
+#include "internal.h"
+#include "get_bits.h"
+#include "dca.h"
+#include "dca_exss.h"
+#include "dcadsp.h"
+#include "dcadct.h"
+#include "fft.h"
+#include "synth_filter.h"
+
+#define DCA_CHANNELS            7
+#define DCA_SUBBANDS            32
+#define DCA_SUBBANDS_X96        64
+#define DCA_SUBFRAMES           16
+#define DCA_SUBBAND_SAMPLES     8
+#define DCA_PCMBLOCK_SAMPLES    32
+#define DCA_ADPCM_COEFFS        4
+#define DCA_LFE_HISTORY         8
+#define DCA_CODE_BOOKS          10
+#define DCA_ABITS_MAX           26
+
+#define DCA_CORE_CHANNELS_MAX       6
+#define DCA_DMIX_CHANNELS_MAX       4
+#define DCA_XXCH_CHANNELS_MAX       2
+#define DCA_EXSS_CHANNELS_MAX       8
+#define DCA_EXSS_CHSETS_MAX         4
+
+#define DCA_FILTER_MODE_X96     0x01
+#define DCA_FILTER_MODE_FIXED   0x02
+
+typedef struct DCADSPData {
+    union {
+        struct {
+            DECLARE_ALIGNED(32, float, hist1)[1024];
+            DECLARE_ALIGNED(32, float, hist2)[64];
+        } flt;
+        struct {
+            DECLARE_ALIGNED(32, int32_t, hist1)[1024];
+            DECLARE_ALIGNED(32, int32_t, hist2)[64];
+        } fix;
+    } u;
+    int offset;
+} DCADSPData;
+
+typedef struct DCACoreDecoder {
+    AVCodecContext  *avctx;
+    GetBitContext   gb;
+
+    // Bit stream header
+    int     crc_present;        ///< CRC present flag
+    int     npcmblocks;         ///< Number of PCM sample blocks
+    int     frame_size;         ///< Primary frame byte size
+    int     audio_mode;         ///< Audio channel arrangement
+    int     sample_rate;        ///< Core audio sampling frequency
+    int     bit_rate;           ///< Transmission bit rate
+    int     drc_present;        ///< Embedded dynamic range flag
+    int     ts_present;         ///< Embedded time stamp flag
+    int     aux_present;        ///< Auxiliary data flag
+    int     ext_audio_type;     ///< Extension audio descriptor flag
+    int     ext_audio_present;  ///< Extended coding flag
+    int     sync_ssf;           ///< Audio sync word insertion flag
+    int     lfe_present;        ///< Low frequency effects flag
+    int     predictor_history;  ///< Predictor history flag switch
+    int     filter_perfect;     ///< Multirate interpolator switch
+    int     source_pcm_res;     ///< Source PCM resolution
+    int     es_format;          ///< Extended surround (ES) mastering flag
+    int     sumdiff_front;      ///< Front sum/difference flag
+    int     sumdiff_surround;   ///< Surround sum/difference flag
+
+    // Primary audio coding header
+    int         nsubframes;     ///< Number of subframes
+    int         nchannels;      ///< Number of primary audio channels (incl. extension channels)
+    int         ch_mask;        ///< Speaker layout mask (incl. LFE and extension channels)
+    int8_t      nsubbands[DCA_CHANNELS];                ///< Subband activity count
+    int8_t      subband_vq_start[DCA_CHANNELS];         ///< High frequency VQ start subband
+    int8_t      joint_intensity_index[DCA_CHANNELS];    ///< Joint intensity coding index
+    int8_t      transition_mode_sel[DCA_CHANNELS];      ///< Transient mode code book
+    int8_t      scale_factor_sel[DCA_CHANNELS];         ///< Scale factor code book
+    int8_t      bit_allocation_sel[DCA_CHANNELS];       ///< Bit allocation quantizer select
+    int8_t      quant_index_sel[DCA_CHANNELS][DCA_CODE_BOOKS];  ///< Quantization index codebook select
+    int32_t     scale_factor_adj[DCA_CHANNELS][DCA_CODE_BOOKS]; ///< Scale factor adjustment
+
+    // Primary audio coding side information
+    int8_t      nsubsubframes[DCA_SUBFRAMES];   ///< Subsubframe count for each subframe
+    int8_t      prediction_mode[DCA_CHANNELS][DCA_SUBBANDS_X96];            ///< Prediction mode
+    int16_t     prediction_vq_index[DCA_CHANNELS][DCA_SUBBANDS_X96];        ///< Prediction coefficients VQ address
+    int8_t      bit_allocation[DCA_CHANNELS][DCA_SUBBANDS_X96];             ///< Bit allocation index
+    int8_t      transition_mode[DCA_SUBFRAMES][DCA_CHANNELS][DCA_SUBBANDS]; ///< Transition mode
+    int32_t     scale_factors[DCA_CHANNELS][DCA_SUBBANDS][2];               ///< Scale factors (2x for transients and X96)
+    int8_t      joint_scale_sel[DCA_CHANNELS];                              ///< Joint subband codebook select
+    int32_t     joint_scale_factors[DCA_CHANNELS][DCA_SUBBANDS_X96];        ///< Scale factors for joint subband coding
+
+    // Auxiliary data
+    int     prim_dmix_embedded; ///< Auxiliary dynamic downmix flag
+    int     prim_dmix_type;     ///< Auxiliary primary channel downmix type
+    int     prim_dmix_coeff[DCA_DMIX_CHANNELS_MAX * DCA_CORE_CHANNELS_MAX]; ///< Dynamic downmix code coefficients
+
+    // Core extensions
+    int     ext_audio_mask;     ///< Bit mask of fully decoded core extensions
+
+    // XCH extension data
+    int     xch_pos;    ///< Bit position of XCH frame in core substream
+
+    // XXCH extension data
+    int     xxch_crc_present;       ///< CRC presence flag for XXCH channel set header
+    int     xxch_mask_nbits;        ///< Number of bits for loudspeaker mask
+    int     xxch_core_mask;         ///< Core loudspeaker activity mask
+    int     xxch_spkr_mask;         ///< Loudspeaker layout mask
+    int     xxch_dmix_embedded;     ///< Downmix already performed by encoder
+    int     xxch_dmix_scale_inv;    ///< Downmix scale factor
+    int     xxch_dmix_mask[DCA_XXCH_CHANNELS_MAX];  ///< Downmix channel mapping mask
+    int     xxch_dmix_coeff[DCA_XXCH_CHANNELS_MAX * DCA_CORE_CHANNELS_MAX];     ///< Downmix coefficients
+    int     xxch_pos;   ///< Bit position of XXCH frame in core substream
+
+    // X96 extension data
+    int     x96_rev_no;         ///< X96 revision number
+    int     x96_crc_present;    ///< CRC presence flag for X96 channel set header
+    int     x96_nchannels;      ///< Number of primary channels in X96 extension
+    int     x96_high_res;       ///< X96 high resolution flag
+    int     x96_subband_start;  ///< First encoded subband in X96 extension
+    int     x96_rand;           ///< Random seed for generating samples for unallocated X96 subbands
+    int     x96_pos;            ///< Bit position of X96 frame in core substream
+
+    // Sample buffers
+    unsigned int    x96_subband_size;
+    int32_t         *x96_subband_buffer;    ///< X96 subband sample buffer base
+    int32_t         *x96_subband_samples[DCA_CHANNELS][DCA_SUBBANDS_X96];   ///< X96 subband samples
+
+    unsigned int    subband_size;
+    int32_t         *subband_buffer;    ///< Subband sample buffer base
+    int32_t         *subband_samples[DCA_CHANNELS][DCA_SUBBANDS];   ///< Subband samples
+    int32_t         *lfe_samples;    ///< Decimated LFE samples
+
+    // DSP contexts
+    DCADSPData              dcadsp_data[DCA_CHANNELS];    ///< FIR history buffers
+    DCADSPContext           *dcadsp;
+    DCADCTContext           dcadct;
+    FFTContext              imdct[2];
+    SynthFilterContext      synth;
+    AVFloatDSPContext       *float_dsp;
+    AVFixedDSPContext       *fixed_dsp;
+
+    // PCM output data
+    unsigned int    output_size;
+    void            *output_buffer;                         ///< PCM output buffer base
+    int32_t         *output_samples[DCA_SPEAKER_COUNT];     ///< PCM output for fixed point mode
+    int32_t         output_history_lfe_fixed;               ///< LFE PCM history for X96 filter
+    float           output_history_lfe_float;               ///< LFE PCM history for X96 filter
+
+    int     ch_remap[DCA_SPEAKER_COUNT];   ///< Channel to speaker map
+    int     request_mask;   ///< Requested channel layout (for stereo downmix)
+
+    int     npcmsamples;    ///< Number of PCM samples per channel
+    int     output_rate;    ///< Output sample rate (1x or 2x header rate)
+
+    int     filter_mode;    ///< Previous filtering mode for detecting changes
+} DCACoreDecoder;
+
+static inline int ff_dca_core_map_spkr(DCACoreDecoder *core, int spkr)
+{
+    if (core->ch_mask & (1U << spkr))
+        return spkr;
+    if (spkr == DCA_SPEAKER_Lss && (core->ch_mask & DCA_SPEAKER_MASK_Ls))
+        return DCA_SPEAKER_Ls;
+    if (spkr == DCA_SPEAKER_Rss && (core->ch_mask & DCA_SPEAKER_MASK_Rs))
+        return DCA_SPEAKER_Rs;
+    return -1;
+}
+
+int ff_dca_core_parse(DCACoreDecoder *s, uint8_t *data, int size);
+int ff_dca_core_parse_exss(DCACoreDecoder *s, uint8_t *data, DCAExssAsset *asset);
+int ff_dca_core_filter_fixed(DCACoreDecoder *s, int x96_synth);
+int ff_dca_core_filter_frame(DCACoreDecoder *s, AVFrame *frame);
+av_cold void ff_dca_core_flush(DCACoreDecoder *s);
+av_cold int ff_dca_core_init(DCACoreDecoder *s);
+av_cold void ff_dca_core_close(DCACoreDecoder *s);
+
+#endif
-- 
2.1.4



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