[FFmpeg-devel] [PATCH v2 15/16] avcodec/dca: add XLL decoder

foo86 foobaz86 at gmail.com
Thu Jan 21 19:49:51 CET 2016


---
 libavcodec/dca_xll.c | 1499 ++++++++++++++++++++++++++++++++++++++++++++++++++
 libavcodec/dca_xll.h |  149 +++++
 2 files changed, 1648 insertions(+)
 create mode 100644 libavcodec/dca_xll.c
 create mode 100644 libavcodec/dca_xll.h

diff --git a/libavcodec/dca_xll.c b/libavcodec/dca_xll.c
new file mode 100644
index 0000000..cd1af81
--- /dev/null
+++ b/libavcodec/dca_xll.c
@@ -0,0 +1,1499 @@
+/*
+ * 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 "dcamath.h"
+#include "dca_syncwords.h"
+#include "unary.h"
+
+static int get_linear(GetBitContext *gb, int n)
+{
+    unsigned int v = get_bits_long(gb, n);
+    return (v >> 1) ^ -(v & 1);
+}
+
+static int get_rice_un(GetBitContext *gb, int k)
+{
+    unsigned int v = get_unary(gb, 1, 128);
+    return (v << k) | get_bits_long(gb, k);
+}
+
+static int get_rice(GetBitContext *gb, int k)
+{
+    unsigned int v = get_rice_un(gb, k);
+    return (v >> 1) ^ -(v & 1);
+}
+
+static void get_array(GetBitContext *gb, int32_t *array, int size, int n)
+{
+    int i;
+
+    for (i = 0; i < size; i++)
+        array[i] = get_bits(gb, n);
+}
+
+static void get_linear_array(GetBitContext *gb, int32_t *array, int size, int n)
+{
+    int i;
+
+    if (n == 0)
+        memset(array, 0, sizeof(*array) * size);
+    else for (i = 0; i < size; i++)
+        array[i] = get_linear(gb, n);
+}
+
+static void get_rice_array(GetBitContext *gb, int32_t *array, int size, int k)
+{
+    int i;
+
+    for (i = 0; i < size; i++)
+        array[i] = get_rice(gb, k);
+}
+
+static int parse_dmix_coeffs(DCAXllDecoder *s, DCAXllChSet *c)
+{
+    // Size of downmix coefficient matrix
+    int m = c->primary_chset ? ff_dca_dmix_primary_nch[c->dmix_type] : c->hier_ofs;
+    int i, j, *coeff_ptr = c->dmix_coeff;
+
+    for (i = 0; i < m; i++) {
+        int code, sign, coeff, scale, scale_inv = 0;
+        unsigned int index;
+
+        // Downmix scale (only for non-primary channel sets)
+        if (!c->primary_chset) {
+            code = get_bits(&s->gb, 9);
+            sign = (code >> 8) - 1;
+            index = (code & 0xff) - FF_DCA_DMIXTABLE_OFFSET;
+            if (index >= FF_DCA_INV_DMIXTABLE_SIZE) {
+                av_log(s->avctx, AV_LOG_ERROR, "Invalid XLL downmix scale index\n");
+                return AVERROR_INVALIDDATA;
+            }
+            scale = ff_dca_dmixtable[index + FF_DCA_DMIXTABLE_OFFSET];
+            scale_inv = ff_dca_inv_dmixtable[index];
+            c->dmix_scale[i] = (scale ^ sign) - sign;
+            c->dmix_scale_inv[i] = (scale_inv ^ sign) - sign;
+        }
+
+        // Downmix coefficients
+        for (j = 0; j < c->nchannels; j++) {
+            code = get_bits(&s->gb, 9);
+            sign = (code >> 8) - 1;
+            index = code & 0xff;
+            if (index >= FF_DCA_DMIXTABLE_SIZE) {
+                av_log(s->avctx, AV_LOG_ERROR, "Invalid XLL downmix coefficient index\n");
+                return AVERROR_INVALIDDATA;
+            }
+            coeff = ff_dca_dmixtable[index];
+            if (!c->primary_chset)
+                // Multiply by |InvDmixScale| to get |UndoDmixScale|
+                coeff = mul16(scale_inv, coeff);
+            *coeff_ptr++ = (coeff ^ sign) - sign;
+        }
+    }
+
+    return 0;
+}
+
+static int chs_parse_header(DCAXllDecoder *s, DCAXllChSet *c, DCAExssAsset *asset)
+{
+    int i, j, k, ret, band, header_size, header_pos = get_bits_count(&s->gb);
+    DCAXllChSet *p = &s->chset[0];
+    DCAXllBand *b;
+
+    // Size of channel set sub-header
+    header_size = get_bits(&s->gb, 10) + 1;
+
+    // Check CRC
+    if ((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 XLL sub-header checksum\n");
+        return AVERROR_INVALIDDATA;
+    }
+
+    // Number of channels in the channel set
+    c->nchannels = get_bits(&s->gb, 4) + 1;
+    if (c->nchannels > DCA_XLL_CHANNELS_MAX) {
+        avpriv_request_sample(s->avctx, "%d XLL channels", c->nchannels);
+        return AVERROR_PATCHWELCOME;
+    }
+
+    // Residual type
+    c->residual_encode = get_bits(&s->gb, c->nchannels);
+
+    // PCM bit resolution
+    c->pcm_bit_res = get_bits(&s->gb, 5) + 1;
+
+    // Storage unit width
+    c->storage_bit_res = get_bits(&s->gb, 5) + 1;
+    if (c->storage_bit_res != 16 && c->storage_bit_res != 24) {
+        avpriv_request_sample(s->avctx, "%d-bit XLL storage resolution", c->storage_bit_res);
+        return AVERROR_PATCHWELCOME;
+    }
+
+    if (c->pcm_bit_res > c->storage_bit_res) {
+        av_log(s->avctx, AV_LOG_ERROR, "Invalid PCM bit resolution for XLL channel set (%d > %d)\n", c->pcm_bit_res, c->storage_bit_res);
+        return AVERROR_INVALIDDATA;
+    }
+
+    // Original sampling frequency
+    c->freq = ff_dca_sampling_freqs[get_bits(&s->gb, 4)];
+    if (c->freq > 192000) {
+        avpriv_request_sample(s->avctx, "%d Hz XLL sampling frequency", c->freq);
+        return AVERROR_PATCHWELCOME;
+    }
+
+    // Sampling frequency modifier
+    if (get_bits(&s->gb, 2)) {
+        avpriv_request_sample(s->avctx, "XLL sampling frequency modifier");
+        return AVERROR_PATCHWELCOME;
+    }
+
+    // Which replacement set this channel set is member of
+    if (get_bits(&s->gb, 2)) {
+        avpriv_request_sample(s->avctx, "XLL replacement set");
+        return AVERROR_PATCHWELCOME;
+    }
+
+    if (asset->one_to_one_map_ch_to_spkr) {
+        // Primary channel set flag
+        c->primary_chset = get_bits1(&s->gb);
+        if (c->primary_chset != (c == p)) {
+            av_log(s->avctx, AV_LOG_ERROR, "The first (and only) XLL channel set must be primary\n");
+            return AVERROR_INVALIDDATA;
+        }
+
+        // Downmix coefficients present in stream
+        c->dmix_coeffs_present = get_bits1(&s->gb);
+
+        // Downmix already performed by encoder
+        c->dmix_embedded = c->dmix_coeffs_present && get_bits1(&s->gb);
+
+        // Downmix type
+        if (c->dmix_coeffs_present && c->primary_chset) {
+            c->dmix_type = get_bits(&s->gb, 3);
+            if (c->dmix_type >= DCA_DMIX_TYPE_COUNT) {
+                av_log(s->avctx, AV_LOG_ERROR, "Invalid XLL primary channel set downmix type\n");
+                return AVERROR_INVALIDDATA;
+            }
+        }
+
+        // Whether the channel set is part of a hierarchy
+        c->hier_chset = get_bits1(&s->gb);
+        if (!c->hier_chset && s->nchsets != 1) {
+            avpriv_request_sample(s->avctx, "XLL channel set outside of hierarchy");
+            return AVERROR_PATCHWELCOME;
+        }
+
+        // Downmix coefficients
+        if (c->dmix_coeffs_present && (ret = parse_dmix_coeffs(s, c)) < 0)
+            return ret;
+
+        // Channel mask enabled
+        if (!get_bits1(&s->gb)) {
+            avpriv_request_sample(s->avctx, "Disabled XLL channel mask");
+            return AVERROR_PATCHWELCOME;
+        }
+
+        // Channel mask for set
+        c->ch_mask = get_bits_long(&s->gb, s->ch_mask_nbits);
+        if (av_popcount(c->ch_mask) != c->nchannels) {
+            av_log(s->avctx, AV_LOG_ERROR, "Invalid XLL channel mask\n");
+            return AVERROR_INVALIDDATA;
+        }
+
+        // Build the channel to speaker map
+        for (i = 0, j = 0; i < s->ch_mask_nbits; i++)
+            if (c->ch_mask & (1U << i))
+                c->ch_remap[j++] = i;
+    } else {
+        // Mapping coeffs present flag
+        if (c->nchannels != 2 || s->nchsets != 1 || get_bits1(&s->gb)) {
+            avpriv_request_sample(s->avctx, "Custom XLL channel to speaker mapping");
+            return AVERROR_PATCHWELCOME;
+        }
+
+        // Setup for LtRt decoding
+        c->primary_chset = 1;
+        c->dmix_coeffs_present = 0;
+        c->dmix_embedded = 0;
+        c->hier_chset = 0;
+        c->ch_mask = DCA_SPEAKER_LAYOUT_STEREO;
+        c->ch_remap[0] = DCA_SPEAKER_L;
+        c->ch_remap[1] = DCA_SPEAKER_R;
+    }
+
+    if (c->freq > 96000) {
+        // Extra frequency bands flag
+        if (get_bits1(&s->gb)) {
+            avpriv_request_sample(s->avctx, "Extra XLL frequency bands");
+            return AVERROR_PATCHWELCOME;
+        }
+        c->nfreqbands = 2;
+    } else {
+        c->nfreqbands = 1;
+    }
+
+    // Set the sampling frequency to that of the first frequency band.
+    // Frequency will be doubled again after bands assembly.
+    c->freq >>= c->nfreqbands - 1;
+
+    // Verify that all channel sets have the same audio characteristics
+    if (c != p && (c->nfreqbands != p->nfreqbands || c->freq != p->freq
+                   || c->pcm_bit_res != p->pcm_bit_res
+                   || c->storage_bit_res != p->storage_bit_res)) {
+        avpriv_request_sample(s->avctx, "Different XLL audio characteristics");
+        return AVERROR_PATCHWELCOME;
+    }
+
+    // Determine number of bits to read bit allocation coding parameter
+    if (c->storage_bit_res > 16)
+        c->nabits = 5;
+    else if (c->storage_bit_res > 8)
+        c->nabits = 4;
+    else
+        c->nabits = 3;
+
+    // Account for embedded downmix and decimator saturation
+    if ((s->nchsets > 1 || c->nfreqbands > 1) && c->nabits < 5)
+        c->nabits++;
+
+    for (band = 0, b = c->bands; band < c->nfreqbands; band++, b++) {
+        // Pairwise channel decorrelation
+        if ((b->decor_enabled = get_bits1(&s->gb)) && c->nchannels > 1) {
+            int ch_nbits = av_ceil_log2(c->nchannels);
+
+            // Original channel order
+            for (i = 0; i < c->nchannels; i++) {
+                b->orig_order[i] = get_bits(&s->gb, ch_nbits);
+                if (b->orig_order[i] >= c->nchannels) {
+                    av_log(s->avctx, AV_LOG_ERROR, "Invalid XLL original channel order\n");
+                    return AVERROR_INVALIDDATA;
+                }
+            }
+
+            // Pairwise channel coefficients
+            for (i = 0; i < c->nchannels / 2; i++)
+                b->decor_coeff[i] = get_bits1(&s->gb) ? get_linear(&s->gb, 7) : 0;
+        } else {
+            for (i = 0; i < c->nchannels; i++)
+                b->orig_order[i] = i;
+            for (i = 0; i < c->nchannels / 2; i++)
+                b->decor_coeff[i] = 0;
+        }
+
+        // Adaptive predictor order
+        b->highest_pred_order = 0;
+        for (i = 0; i < c->nchannels; i++) {
+            b->adapt_pred_order[i] = get_bits(&s->gb, 4);
+            if (b->adapt_pred_order[i] > b->highest_pred_order)
+                b->highest_pred_order = b->adapt_pred_order[i];
+        }
+        if (b->highest_pred_order > s->nsegsamples) {
+            av_log(s->avctx, AV_LOG_ERROR, "Invalid XLL adaptive predicition order\n");
+            return AVERROR_INVALIDDATA;
+        }
+
+        // Fixed predictor order
+        for (i = 0; i < c->nchannels; i++)
+            b->fixed_pred_order[i] = b->adapt_pred_order[i] ? 0 : get_bits(&s->gb, 2);
+
+        // Adaptive predictor quantized reflection coefficients
+        for (i = 0; i < c->nchannels; i++) {
+            for (j = 0; j < b->adapt_pred_order[i]; j++) {
+                k = get_linear(&s->gb, 8);
+                if (k == -128) {
+                    av_log(s->avctx, AV_LOG_ERROR, "Invalid XLL reflection coefficient index\n");
+                    return AVERROR_INVALIDDATA;
+                }
+                if (k < 0)
+                    b->adapt_refl_coeff[i][j] = -(int)ff_dca_xll_refl_coeff[-k];
+                else
+                    b->adapt_refl_coeff[i][j] =  (int)ff_dca_xll_refl_coeff[ k];
+            }
+        }
+
+        // Downmix performed by encoder in extension frequency band
+        b->dmix_embedded = c->dmix_embedded && (band == 0 || get_bits1(&s->gb));
+
+        // MSB/LSB split flag in extension frequency band
+        if ((band == 0 && s->scalable_lsbs) || (band != 0 && get_bits1(&s->gb))) {
+            // Size of LSB section in any segment
+            b->lsb_section_size = get_bits_long(&s->gb, s->seg_size_nbits);
+            if (b->lsb_section_size < 0 || b->lsb_section_size > s->frame_size) {
+                av_log(s->avctx, AV_LOG_ERROR, "Invalid LSB section size\n");
+                return AVERROR_INVALIDDATA;
+            }
+
+            // Account for optional CRC bytes after LSB section
+            if (b->lsb_section_size && (s->band_crc_present > 2 ||
+                                        (band == 0 && s->band_crc_present > 1)))
+                b->lsb_section_size += 2;
+
+            // Number of bits to represent the samples in LSB part
+            for (i = 0; i < c->nchannels; i++) {
+                b->nscalablelsbs[i] = get_bits(&s->gb, 4);
+                if (b->nscalablelsbs[i] && !b->lsb_section_size) {
+                    av_log(s->avctx, AV_LOG_ERROR, "LSB section missing with non-zero LSB width\n");
+                    return AVERROR_INVALIDDATA;
+                }
+            }
+        } else {
+            b->lsb_section_size = 0;
+            for (i = 0; i < c->nchannels; i++)
+                b->nscalablelsbs[i] = 0;
+        }
+
+        // Scalable resolution flag in extension frequency band
+        if ((band == 0 && s->scalable_lsbs) || (band != 0 && get_bits1(&s->gb))) {
+            // Number of bits discarded by authoring
+            for (i = 0; i < c->nchannels; i++)
+                b->bit_width_adjust[i] = get_bits(&s->gb, 4);
+        } else {
+            for (i = 0; i < c->nchannels; i++)
+                b->bit_width_adjust[i] = 0;
+        }
+    }
+
+    // Reserved
+    // Byte align
+    // CRC16 of channel set sub-header
+    if (ff_dca_seek_bits(&s->gb, header_pos + header_size * 8)) {
+        av_log(s->avctx, AV_LOG_ERROR, "Read past end of XLL sub-header\n");
+        return AVERROR_INVALIDDATA;
+    }
+
+    return 0;
+}
+
+static int chs_alloc_msb_band_data(DCAXllDecoder *s, DCAXllChSet *c)
+{
+    int ndecisamples = c->nfreqbands > 1 ? DCA_XLL_DECI_HISTORY_MAX : 0;
+    int nchsamples = s->nframesamples + ndecisamples;
+    int i, j, nsamples = nchsamples * c->nchannels * c->nfreqbands;
+    int32_t *ptr;
+
+    // Reallocate MSB sample buffer
+    av_fast_malloc(&c->sample_buffer[0], &c->sample_size[0], nsamples * sizeof(int32_t));
+    if (!c->sample_buffer[0])
+        return AVERROR(ENOMEM);
+
+    ptr = c->sample_buffer[0] + ndecisamples;
+    for (i = 0; i < c->nfreqbands; i++) {
+        for (j = 0; j < c->nchannels; j++) {
+            c->bands[i].msb_sample_buffer[j] = ptr;
+            ptr += nchsamples;
+        }
+    }
+
+    return 0;
+}
+
+static int chs_alloc_lsb_band_data(DCAXllDecoder *s, DCAXllChSet *c)
+{
+    int i, j, nsamples = 0;
+    int32_t *ptr;
+
+    // Determine number of frequency bands that have MSB/LSB split
+    for (i = 0; i < c->nfreqbands; i++)
+        if (c->bands[i].lsb_section_size)
+            nsamples += s->nframesamples * c->nchannels;
+    if (!nsamples)
+        return 0;
+
+    // Reallocate LSB sample buffer
+    av_fast_malloc(&c->sample_buffer[1], &c->sample_size[1], nsamples * sizeof(int32_t));
+    if (!c->sample_buffer[1])
+        return AVERROR(ENOMEM);
+
+    ptr = c->sample_buffer[1];
+    for (i = 0; i < c->nfreqbands; i++) {
+        if (c->bands[i].lsb_section_size) {
+            for (j = 0; j < c->nchannels; j++) {
+                c->bands[i].lsb_sample_buffer[j] = ptr;
+                ptr += s->nframesamples;
+            }
+        } else {
+            for (j = 0; j < c->nchannels; j++)
+                c->bands[i].lsb_sample_buffer[j] = NULL;
+        }
+    }
+
+    return 0;
+}
+
+static int chs_parse_band_data(DCAXllDecoder *s, DCAXllChSet *c, int band, int seg, int band_data_end)
+{
+    DCAXllBand *b = &c->bands[band];
+    int i, j, k;
+
+    // Start unpacking MSB portion of the segment
+    if (!(seg && get_bits1(&s->gb))) {
+        // Unpack segment type
+        // 0 - distinct coding parameters for each channel
+        // 1 - common coding parameters for all channels
+        c->seg_common = get_bits1(&s->gb);
+
+        // Determine number of coding parameters encoded in segment
+        k = c->seg_common ? 1 : c->nchannels;
+
+        // Unpack Rice coding parameters
+        for (i = 0; i < k; i++) {
+            // Unpack Rice coding flag
+            // 0 - linear code, 1 - Rice code
+            c->rice_code_flag[i] = get_bits1(&s->gb);
+            if (!c->seg_common && c->rice_code_flag[i]) {
+                // Unpack Hybrid Rice coding flag
+                // 0 - Rice code, 1 - Hybrid Rice code
+                if (get_bits1(&s->gb))
+                    // Unpack binary code length for isolated samples
+                    c->bitalloc_hybrid_linear[i] = get_bits(&s->gb, c->nabits) + 1;
+                else
+                    // 0 indicates no Hybrid Rice coding
+                    c->bitalloc_hybrid_linear[i] = 0;
+            } else {
+                // 0 indicates no Hybrid Rice coding
+                c->bitalloc_hybrid_linear[i] = 0;
+            }
+        }
+
+        // Unpack coding parameters
+        for (i = 0; i < k; i++) {
+            if (seg == 0) {
+                // Unpack coding parameter for part A of segment 0
+                c->bitalloc_part_a[i] = get_bits(&s->gb, c->nabits);
+
+                // Adjust for the linear code
+                if (!c->rice_code_flag[i] && c->bitalloc_part_a[i])
+                    c->bitalloc_part_a[i]++;
+
+                if (!c->seg_common)
+                    c->nsamples_part_a[i] = b->adapt_pred_order[i];
+                else
+                    c->nsamples_part_a[i] = b->highest_pred_order;
+            } else {
+                c->bitalloc_part_a[i] = 0;
+                c->nsamples_part_a[i] = 0;
+            }
+
+            // Unpack coding parameter for part B of segment
+            c->bitalloc_part_b[i] = get_bits(&s->gb, c->nabits);
+
+            // Adjust for the linear code
+            if (!c->rice_code_flag[i] && c->bitalloc_part_b[i])
+                c->bitalloc_part_b[i]++;
+        }
+    }
+
+    // Unpack entropy codes
+    for (i = 0; i < c->nchannels; i++) {
+        int32_t *part_a, *part_b;
+        int nsamples_part_b;
+
+        // Select index of coding parameters
+        k = c->seg_common ? 0 : i;
+
+        // Slice the segment into parts A and B
+        part_a = b->msb_sample_buffer[i] + seg * s->nsegsamples;
+        part_b = part_a + c->nsamples_part_a[k];
+        nsamples_part_b = s->nsegsamples - c->nsamples_part_a[k];
+
+        if (get_bits_left(&s->gb) < 0)
+            return AVERROR_INVALIDDATA;
+
+        if (!c->rice_code_flag[k]) {
+            // Linear codes
+            // Unpack all residuals of part A of segment 0
+            get_linear_array(&s->gb, part_a, c->nsamples_part_a[k],
+                             c->bitalloc_part_a[k]);
+
+            // Unpack all residuals of part B of segment 0 and others
+            get_linear_array(&s->gb, part_b, nsamples_part_b,
+                             c->bitalloc_part_b[k]);
+        } else {
+            // Rice codes
+            // Unpack all residuals of part A of segment 0
+            get_rice_array(&s->gb, part_a, c->nsamples_part_a[k],
+                           c->bitalloc_part_a[k]);
+
+            if (c->bitalloc_hybrid_linear[k]) {
+                // Hybrid Rice codes
+                // Unpack the number of isolated samples
+                int nisosamples = get_bits(&s->gb, s->nsegsamples_log2);
+
+                // Set all locations to 0
+                memset(part_b, 0, sizeof(*part_b) * nsamples_part_b);
+
+                // Extract the locations of isolated samples and flag by -1
+                for (j = 0; j < nisosamples; j++) {
+                    int loc = get_bits(&s->gb, s->nsegsamples_log2);
+                    if (loc >= nsamples_part_b) {
+                        av_log(s->avctx, AV_LOG_ERROR, "Invalid isolated sample location\n");
+                        return AVERROR_INVALIDDATA;
+                    }
+                    part_b[loc] = -1;
+                }
+
+                // Unpack all residuals of part B of segment 0 and others
+                for (j = 0; j < nsamples_part_b; j++) {
+                    if (part_b[j])
+                        part_b[j] = get_linear(&s->gb, c->bitalloc_hybrid_linear[k]);
+                    else
+                        part_b[j] = get_rice(&s->gb, c->bitalloc_part_b[k]);
+                }
+            } else {
+                // Rice codes
+                // Unpack all residuals of part B of segment 0 and others
+                get_rice_array(&s->gb, part_b, nsamples_part_b, c->bitalloc_part_b[k]);
+            }
+        }
+    }
+
+    // Unpack decimator history for frequency band 1
+    if (seg == 0 && band == 1) {
+        int nbits = get_bits(&s->gb, 5) + 1;
+        for (i = 0; i < c->nchannels; i++)
+            for (j = 1; j < DCA_XLL_DECI_HISTORY_MAX; j++)
+                c->deci_history[i][j] = get_sbits_long(&s->gb, nbits);
+    }
+
+    // Start unpacking LSB portion of the segment
+    if (b->lsb_section_size) {
+        // Skip to the start of LSB portion
+        if (ff_dca_seek_bits(&s->gb, band_data_end - b->lsb_section_size * 8)) {
+            av_log(s->avctx, AV_LOG_ERROR, "Read past end of XLL band data\n");
+            return AVERROR_INVALIDDATA;
+        }
+
+        // Unpack all LSB parts of residuals of this segment
+        for (i = 0; i < c->nchannels; i++) {
+            if (b->nscalablelsbs[i]) {
+                get_array(&s->gb,
+                          b->lsb_sample_buffer[i] + seg * s->nsegsamples,
+                          s->nsegsamples, b->nscalablelsbs[i]);
+            }
+        }
+    }
+
+    // Skip to the end of band data
+    if (ff_dca_seek_bits(&s->gb, band_data_end)) {
+        av_log(s->avctx, AV_LOG_ERROR, "Read past end of XLL band data\n");
+        return AVERROR_INVALIDDATA;
+    }
+
+    return 0;
+}
+
+static void av_cold chs_clear_band_data(DCAXllDecoder *s, DCAXllChSet *c, int band, int seg)
+{
+    DCAXllBand *b = &c->bands[band];
+    int i, offset, nsamples;
+
+    if (seg < 0) {
+        offset = 0;
+        nsamples = s->nframesamples;
+    } else {
+        offset = seg * s->nsegsamples;
+        nsamples = s->nsegsamples;
+    }
+
+    for (i = 0; i < c->nchannels; i++) {
+        memset(b->msb_sample_buffer[i] + offset, 0, nsamples * sizeof(int32_t));
+        if (b->lsb_section_size)
+            memset(b->lsb_sample_buffer[i] + offset, 0, nsamples * sizeof(int32_t));
+    }
+
+    if (seg <= 0 && band)
+        memset(c->deci_history, 0, sizeof(c->deci_history));
+
+    if (seg < 0) {
+        memset(b->nscalablelsbs, 0, sizeof(b->nscalablelsbs));
+        memset(b->bit_width_adjust, 0, sizeof(b->bit_width_adjust));
+    }
+}
+
+static void chs_filter_band_data(DCAXllDecoder *s, DCAXllChSet *c, int band)
+{
+    DCAXllBand *b = &c->bands[band];
+    int nsamples = s->nframesamples;
+    int i, j, k;
+
+    // Inverse adaptive or fixed prediction
+    for (i = 0; i < c->nchannels; i++) {
+        int32_t *buf = b->msb_sample_buffer[i];
+        int order = b->adapt_pred_order[i];
+        if (order > 0) {
+            int coeff[DCA_XLL_ADAPT_PRED_ORDER_MAX];
+            // Conversion from reflection coefficients to direct form coefficients
+            for (j = 0; j < order; j++) {
+                int rc = b->adapt_refl_coeff[i][j];
+                for (k = 0; k < (j + 1) / 2; k++) {
+                    int tmp1 = coeff[    k    ];
+                    int tmp2 = coeff[j - k - 1];
+                    coeff[    k    ] = tmp1 + mul16(rc, tmp2);
+                    coeff[j - k - 1] = tmp2 + mul16(rc, tmp1);
+                }
+                coeff[j] = rc;
+            }
+            // Inverse adaptive prediction
+            for (j = 0; j < nsamples - order; j++) {
+                int64_t err = 0;
+                for (k = 0; k < order; k++)
+                    err += (int64_t)buf[j + k] * coeff[order - k - 1];
+                buf[j + k] -= clip23(norm16(err));
+            }
+        } else {
+            // Inverse fixed coefficient prediction
+            for (j = 0; j < b->fixed_pred_order[i]; j++)
+                for (k = 1; k < nsamples; k++)
+                    buf[k] += buf[k - 1];
+        }
+    }
+
+    // Inverse pairwise channel decorrellation
+    if (b->decor_enabled) {
+        int32_t *tmp[DCA_XLL_CHANNELS_MAX];
+
+        for (i = 0; i < c->nchannels / 2; i++) {
+            int coeff = b->decor_coeff[i];
+            if (coeff) {
+                s->dcadsp->decor(b->msb_sample_buffer[i * 2 + 1],
+                                 b->msb_sample_buffer[i * 2    ],
+                                 coeff, nsamples);
+            }
+        }
+
+        // Reorder channel pointers to the original order
+        for (i = 0; i < c->nchannels; i++)
+            tmp[i] = b->msb_sample_buffer[i];
+
+        for (i = 0; i < c->nchannels; i++)
+            b->msb_sample_buffer[b->orig_order[i]] = tmp[i];
+    }
+
+    // Map output channel pointers for frequency band 0
+    if (c->nfreqbands == 1)
+        for (i = 0; i < c->nchannels; i++)
+            s->output_samples[c->ch_remap[i]] = b->msb_sample_buffer[i];
+}
+
+static int chs_get_lsb_width(DCAXllDecoder *s, DCAXllChSet *c, int band, int ch)
+{
+    int adj = c->bands[band].bit_width_adjust[ch];
+    int shift = c->bands[band].nscalablelsbs[ch];
+
+    if (s->fixed_lsb_width)
+        shift = s->fixed_lsb_width;
+    else if (shift && adj)
+        shift += adj - 1;
+    else
+        shift += adj;
+
+    return shift;
+}
+
+static void chs_assemble_msbs_lsbs(DCAXllDecoder *s, DCAXllChSet *c, int band)
+{
+    DCAXllBand *b = &c->bands[band];
+    int n, ch, nsamples = s->nframesamples;
+
+    for (ch = 0; ch < c->nchannels; ch++) {
+        int shift = chs_get_lsb_width(s, c, band, ch);
+        if (shift) {
+            int32_t *msb = b->msb_sample_buffer[ch];
+            if (b->nscalablelsbs[ch]) {
+                int32_t *lsb = b->lsb_sample_buffer[ch];
+                int adj = b->bit_width_adjust[ch];
+                for (n = 0; n < nsamples; n++)
+                    msb[n] = msb[n] * (1 << shift) + (lsb[n] << adj);
+            } else {
+                for (n = 0; n < nsamples; n++)
+                    msb[n] = msb[n] * (1 << shift);
+            }
+        }
+    }
+}
+
+static int chs_assemble_freq_bands(DCAXllDecoder *s, DCAXllChSet *c)
+{
+    int ch, nsamples = s->nframesamples;
+    int32_t *ptr;
+
+    av_assert1(c->nfreqbands > 1);
+
+    // Reallocate frequency band assembly buffer
+    av_fast_malloc(&c->sample_buffer[2], &c->sample_size[2],
+                   2 * nsamples * c->nchannels * sizeof(int32_t));
+    if (!c->sample_buffer[2])
+        return AVERROR(ENOMEM);
+
+    // Assemble frequency bands 0 and 1
+    ptr = c->sample_buffer[2];
+    for (ch = 0; ch < c->nchannels; ch++) {
+        int32_t *band0 = c->bands[0].msb_sample_buffer[ch];
+        int32_t *band1 = c->bands[1].msb_sample_buffer[ch];
+
+        // Copy decimator history
+        memcpy(band0 - DCA_XLL_DECI_HISTORY_MAX,
+               c->deci_history[ch], sizeof(c->deci_history[0]));
+
+        // Filter
+        s->dcadsp->assemble_freq_bands(ptr, band0, band1,
+                                       ff_dca_xll_band_coeff,
+                                       nsamples);
+
+        // Remap output channel pointer to assembly buffer
+        s->output_samples[c->ch_remap[ch]] = ptr;
+        ptr += nsamples * 2;
+    }
+
+    return 0;
+}
+
+static int parse_common_header(DCAXllDecoder *s)
+{
+    int stream_ver, header_size, frame_size_nbits, nframesegs_log2;
+
+    // XLL extension sync word
+    if (get_bits_long(&s->gb, 32) != DCA_SYNCWORD_XLL) {
+        av_log(s->avctx, AV_LOG_VERBOSE, "Invalid XLL sync word\n");
+        return AVERROR(EAGAIN);
+    }
+
+    // Version number
+    stream_ver = get_bits(&s->gb, 4) + 1;
+    if (stream_ver > 1) {
+        avpriv_request_sample(s->avctx, "XLL stream version %d", stream_ver);
+        return AVERROR_PATCHWELCOME;
+    }
+
+    // Lossless frame header length
+    header_size = get_bits(&s->gb, 8) + 1;
+
+    // Check CRC
+    if ((s->avctx->err_recognition & (AV_EF_CRCCHECK | AV_EF_CAREFUL))
+        && ff_dca_check_crc(&s->gb, 32, header_size * 8)) {
+        av_log(s->avctx, AV_LOG_ERROR, "Invalid XLL common header checksum\n");
+        return AVERROR_INVALIDDATA;
+    }
+
+    // Number of bits used to read frame size
+    frame_size_nbits = get_bits(&s->gb, 5) + 1;
+
+    // Number of bytes in a lossless frame
+    s->frame_size = get_bits_long(&s->gb, frame_size_nbits);
+    if (s->frame_size < 0 || s->frame_size >= DCA_XLL_PBR_BUFFER_MAX) {
+        av_log(s->avctx, AV_LOG_ERROR, "Invalid XLL frame size (%d bytes)\n", s->frame_size);
+        return AVERROR_INVALIDDATA;
+    }
+    s->frame_size++;
+
+    // Number of channels sets per frame
+    s->nchsets = get_bits(&s->gb, 4) + 1;
+    if (s->nchsets > DCA_XLL_CHSETS_MAX) {
+        avpriv_request_sample(s->avctx, "%d XLL channel sets", s->nchsets);
+        return AVERROR_PATCHWELCOME;
+    }
+
+    // Number of segments per frame
+    nframesegs_log2 = get_bits(&s->gb, 4);
+    s->nframesegs = 1 << nframesegs_log2;
+    if (s->nframesegs > 1024) {
+        av_log(s->avctx, AV_LOG_ERROR, "Too many segments per XLL frame\n");
+        return AVERROR_INVALIDDATA;
+    }
+
+    // Samples in segment per one frequency band for the first channel set
+    // Maximum value is 256 for sampling frequencies <= 48 kHz
+    // Maximum value is 512 for sampling frequencies > 48 kHz
+    s->nsegsamples_log2 = get_bits(&s->gb, 4);
+    if (!s->nsegsamples_log2) {
+        av_log(s->avctx, AV_LOG_ERROR, "Too few samples per XLL segment\n");
+        return AVERROR_INVALIDDATA;
+    }
+    s->nsegsamples = 1 << s->nsegsamples_log2;
+    if (s->nsegsamples > 512) {
+        av_log(s->avctx, AV_LOG_ERROR, "Too many samples per XLL segment\n");
+        return AVERROR_INVALIDDATA;
+    }
+
+    // Samples in frame per one frequency band for the first channel set
+    s->nframesamples_log2 = s->nsegsamples_log2 + nframesegs_log2;
+    s->nframesamples = 1 << s->nframesamples_log2;
+    if (s->nframesamples > 65536) {
+        av_log(s->avctx, AV_LOG_ERROR, "Too many samples per XLL frame\n");
+        return AVERROR_INVALIDDATA;
+    }
+
+    // Number of bits used to read segment size
+    s->seg_size_nbits = get_bits(&s->gb, 5) + 1;
+
+    // Presence of CRC16 within each frequency band
+    // 0 - No CRC16 within band
+    // 1 - CRC16 placed at the end of MSB0
+    // 2 - CRC16 placed at the end of MSB0 and LSB0
+    // 3 - CRC16 placed at the end of MSB0 and LSB0 and other frequency bands
+    s->band_crc_present = get_bits(&s->gb, 2);
+
+    // MSB/LSB split flag
+    s->scalable_lsbs = get_bits1(&s->gb);
+
+    // Channel position mask
+    s->ch_mask_nbits = get_bits(&s->gb, 5) + 1;
+
+    // Fixed LSB width
+    if (s->scalable_lsbs)
+        s->fixed_lsb_width = get_bits(&s->gb, 4);
+    else
+        s->fixed_lsb_width = 0;
+
+    // Reserved
+    // Byte align
+    // Header CRC16 protection
+    if (ff_dca_seek_bits(&s->gb, header_size * 8)) {
+        av_log(s->avctx, AV_LOG_ERROR, "Read past end of XLL common header\n");
+        return AVERROR_INVALIDDATA;
+    }
+
+    return 0;
+}
+
+static int is_hier_dmix_chset(DCAXllChSet *c)
+{
+    return !c->primary_chset && c->dmix_embedded && c->hier_chset;
+}
+
+static DCAXllChSet *find_next_hier_dmix_chset(DCAXllDecoder *s, DCAXllChSet *c)
+{
+    if (c->hier_chset)
+        while (++c < &s->chset[s->nchsets])
+            if (is_hier_dmix_chset(c))
+                return c;
+
+    return NULL;
+}
+
+static void prescale_down_mix(DCAXllChSet *c, DCAXllChSet *o)
+{
+    int i, j, *coeff_ptr = c->dmix_coeff;
+
+    for (i = 0; i < c->hier_ofs; i++) {
+        int scale = o->dmix_scale[i];
+        int scale_inv = o->dmix_scale_inv[i];
+        c->dmix_scale[i] = mul15(c->dmix_scale[i], scale);
+        c->dmix_scale_inv[i] = mul16(c->dmix_scale_inv[i], scale_inv);
+        for (j = 0; j < c->nchannels; j++) {
+            int coeff = mul16(*coeff_ptr, scale_inv);
+            *coeff_ptr++ = mul15(coeff, o->dmix_scale[c->hier_ofs + j]);
+        }
+    }
+}
+
+static int parse_sub_headers(DCAXllDecoder *s, DCAExssAsset *asset)
+{
+    DCAContext *dca = s->avctx->priv_data;
+    DCAXllChSet *c;
+    int i, ret;
+
+    // Parse channel set headers
+    s->nfreqbands = 0;
+    s->nchannels = 0;
+    s->nreschsets = 0;
+    for (i = 0, c = s->chset; i < s->nchsets; i++, c++) {
+        c->hier_ofs = s->nchannels;
+        if ((ret = chs_parse_header(s, c, asset)) < 0)
+            return ret;
+        if (c->nfreqbands > s->nfreqbands)
+            s->nfreqbands = c->nfreqbands;
+        if (c->hier_chset)
+            s->nchannels += c->nchannels;
+        if (c->residual_encode != (1 << c->nchannels) - 1)
+            s->nreschsets++;
+    }
+
+    // Pre-scale downmixing coefficients for all non-primary channel sets
+    for (i = s->nchsets - 1, c = &s->chset[i]; i > 0; i--, c--) {
+        if (is_hier_dmix_chset(c)) {
+            DCAXllChSet *o = find_next_hier_dmix_chset(s, c);
+            if (o)
+                prescale_down_mix(c, o);
+        }
+    }
+
+    // Determine number of active channel sets to decode
+    switch (dca->request_channel_layout) {
+    case DCA_SPEAKER_LAYOUT_STEREO:
+        s->nactivechsets = 1;
+        break;
+    case DCA_SPEAKER_LAYOUT_5POINT0:
+    case DCA_SPEAKER_LAYOUT_5POINT1:
+        s->nactivechsets = (s->chset[0].nchannels < 5 && s->nchsets > 1) ? 2 : 1;
+        break;
+    default:
+        s->nactivechsets = s->nchsets;
+        break;
+    }
+
+    return 0;
+}
+
+static int parse_navi_table(DCAXllDecoder *s)
+{
+    int chs, seg, band, navi_nb, navi_pos, *navi_ptr;
+    DCAXllChSet *c;
+
+    // Determine size of NAVI table
+    navi_nb = s->nfreqbands * s->nframesegs * s->nchsets;
+    if (navi_nb > 1024) {
+        av_log(s->avctx, AV_LOG_ERROR, "Too many NAVI entries (%d)\n", navi_nb);
+        return AVERROR_INVALIDDATA;
+    }
+
+    // Reallocate NAVI table
+    av_fast_malloc(&s->navi, &s->navi_size, navi_nb * sizeof(*s->navi));
+    if (!s->navi)
+        return AVERROR(ENOMEM);
+
+    // Parse NAVI
+    navi_pos = get_bits_count(&s->gb);
+    navi_ptr = s->navi;
+    for (band = 0; band < s->nfreqbands; band++) {
+        for (seg = 0; seg < s->nframesegs; seg++) {
+            for (chs = 0, c = s->chset; chs < s->nchsets; chs++, c++) {
+                int size = 0;
+                if (c->nfreqbands > band) {
+                    size = get_bits_long(&s->gb, s->seg_size_nbits);
+                    if (size < 0 || size >= s->frame_size) {
+                        av_log(s->avctx, AV_LOG_ERROR, "Invalid NAVI segment size (%d bytes)\n", size);
+                        return AVERROR_INVALIDDATA;
+                    }
+                    size++;
+                }
+                *navi_ptr++ = size;
+            }
+        }
+    }
+
+    // Byte align
+    // CRC16
+    skip_bits(&s->gb, -get_bits_count(&s->gb) & 7);
+    skip_bits(&s->gb, 16);
+
+    // Check CRC
+    if ((s->avctx->err_recognition & (AV_EF_CRCCHECK | AV_EF_CAREFUL))
+        && ff_dca_check_crc(&s->gb, navi_pos, get_bits_count(&s->gb))) {
+        av_log(s->avctx, AV_LOG_ERROR, "Invalid NAVI checksum\n");
+        return AVERROR_INVALIDDATA;
+    }
+
+    return 0;
+}
+
+static int parse_band_data(DCAXllDecoder *s)
+{
+    int ret, chs, seg, band, navi_pos, *navi_ptr;
+    DCAXllChSet *c;
+
+    for (chs = 0, c = s->chset; chs < s->nactivechsets; chs++, c++) {
+        if ((ret = chs_alloc_msb_band_data(s, c)) < 0)
+            return ret;
+        if ((ret = chs_alloc_lsb_band_data(s, c)) < 0)
+            return ret;
+    }
+
+    navi_pos = get_bits_count(&s->gb);
+    navi_ptr = s->navi;
+    for (band = 0; band < s->nfreqbands; band++) {
+        for (seg = 0; seg < s->nframesegs; seg++) {
+            for (chs = 0, c = s->chset; chs < s->nchsets; chs++, c++) {
+                if (c->nfreqbands > band) {
+                    navi_pos += *navi_ptr * 8;
+                    if (navi_pos > s->gb.size_in_bits) {
+                        av_log(s->avctx, AV_LOG_ERROR, "Invalid NAVI position\n");
+                        return AVERROR_INVALIDDATA;
+                    }
+                    if (chs < s->nactivechsets &&
+                        (ret = chs_parse_band_data(s, c, band, seg, navi_pos)) < 0) {
+                        if (s->avctx->err_recognition & AV_EF_EXPLODE)
+                            return ret;
+                        chs_clear_band_data(s, c, band, seg);
+                    }
+                    s->gb.index = navi_pos;
+                }
+                navi_ptr++;
+            }
+        }
+    }
+
+    return 0;
+}
+
+static int parse_frame(DCAXllDecoder *s, uint8_t *data, int size, DCAExssAsset *asset)
+{
+    int ret;
+
+    if ((ret = init_get_bits8(&s->gb, data, size)) < 0)
+        return ret;
+    if ((ret = parse_common_header(s)) < 0)
+        return ret;
+    if ((ret = parse_sub_headers(s, asset)) < 0)
+        return ret;
+    if ((ret = parse_navi_table(s)) < 0)
+        return ret;
+    if ((ret = parse_band_data(s)) < 0)
+        return ret;
+    if (ff_dca_seek_bits(&s->gb, s->frame_size * 8)) {
+        av_log(s->avctx, AV_LOG_ERROR, "Read past end of XLL frame\n");
+        return AVERROR_INVALIDDATA;
+    }
+    return ret;
+}
+
+static void clear_pbr(DCAXllDecoder *s)
+{
+    s->pbr_length = 0;
+    s->pbr_delay = 0;
+}
+
+static int copy_to_pbr(DCAXllDecoder *s, uint8_t *data, int size, int delay)
+{
+    if (size > DCA_XLL_PBR_BUFFER_MAX)
+        return AVERROR(ENOSPC);
+
+    if (!s->pbr_buffer && !(s->pbr_buffer = av_malloc(DCA_XLL_PBR_BUFFER_MAX + DCA_BUFFER_PADDING_SIZE)))
+        return AVERROR(ENOMEM);
+
+    memcpy(s->pbr_buffer, data, size);
+    s->pbr_length = size;
+    s->pbr_delay = delay;
+    return 0;
+}
+
+static int parse_frame_no_pbr(DCAXllDecoder *s, uint8_t *data, int size, DCAExssAsset *asset)
+{
+    int ret = parse_frame(s, data, size, asset);
+
+    // If XLL packet data didn't start with a sync word, we must have jumped
+    // right into the middle of PBR smoothing period
+    if (ret == AVERROR(EAGAIN) && asset->xll_sync_present && asset->xll_sync_offset < size) {
+        // Skip to the next sync word in this packet
+        data += asset->xll_sync_offset;
+        size -= asset->xll_sync_offset;
+
+        // If decoding delay is set, put the frame into PBR buffer and return
+        // failure code. Higher level decoder is expected to switch to lossy
+        // core decoding or mute its output until decoding delay expires.
+        if (asset->xll_delay_nframes > 0) {
+            if ((ret = copy_to_pbr(s, data, size, asset->xll_delay_nframes)) < 0)
+                return ret;
+            return AVERROR(EAGAIN);
+        }
+
+        // No decoding delay, just parse the frame in place
+        ret = parse_frame(s, data, size, asset);
+    }
+
+    if (ret < 0)
+        return ret;
+
+    if (s->frame_size > size)
+        return AVERROR(EINVAL);
+
+    // If the XLL decoder didn't consume full packet, start PBR smoothing period
+    if (s->frame_size < size)
+        if ((ret = copy_to_pbr(s, data + s->frame_size, size - s->frame_size, 0)) < 0)
+            return ret;
+
+    return 0;
+}
+
+static int parse_frame_pbr(DCAXllDecoder *s, uint8_t *data, int size, DCAExssAsset *asset)
+{
+    int ret;
+
+    if (size > DCA_XLL_PBR_BUFFER_MAX - s->pbr_length) {
+        ret = AVERROR(ENOSPC);
+        goto fail;
+    }
+
+    memcpy(s->pbr_buffer + s->pbr_length, data, size);
+    s->pbr_length += size;
+
+    // Respect decoding delay after synchronization error
+    if (s->pbr_delay > 0 && --s->pbr_delay)
+        return AVERROR(EAGAIN);
+
+    if ((ret = parse_frame(s, s->pbr_buffer, s->pbr_length, asset)) < 0)
+        goto fail;
+
+    if (s->frame_size > s->pbr_length) {
+        ret = AVERROR(EINVAL);
+        goto fail;
+    }
+
+    if (s->frame_size == s->pbr_length) {
+        // End of PBR smoothing period
+        clear_pbr(s);
+    } else {
+        s->pbr_length -= s->frame_size;
+        memmove(s->pbr_buffer, s->pbr_buffer + s->frame_size, s->pbr_length);
+    }
+
+    return 0;
+
+fail:
+    // For now, throw out all PBR state on failure.
+    // Perhaps we can be smarter and try to resync somehow.
+    clear_pbr(s);
+    return ret;
+}
+
+int ff_dca_xll_parse(DCAXllDecoder *s, uint8_t *data, DCAExssAsset *asset)
+{
+    int ret;
+
+    if (s->hd_stream_id != asset->hd_stream_id) {
+        clear_pbr(s);
+        s->hd_stream_id = asset->hd_stream_id;
+    }
+
+    if (s->pbr_length)
+        ret = parse_frame_pbr(s, data + asset->xll_offset, asset->xll_size, asset);
+    else
+        ret = parse_frame_no_pbr(s, data + asset->xll_offset, asset->xll_size, asset);
+
+    return ret;
+}
+
+static void undo_down_mix(DCAXllDecoder *s, DCAXllChSet *o, int band)
+{
+    int i, j, k, nchannels = 0, *coeff_ptr = o->dmix_coeff;
+    DCAXllChSet *c;
+
+    for (i = 0, c = s->chset; i < s->nactivechsets; i++, c++) {
+        if (!c->hier_chset)
+            continue;
+
+        av_assert1(band < c->nfreqbands);
+        for (j = 0; j < c->nchannels; j++) {
+            for (k = 0; k < o->nchannels; k++) {
+                int coeff = *coeff_ptr++;
+                if (coeff) {
+                    s->dcadsp->dmix_sub(c->bands[band].msb_sample_buffer[j],
+                                        o->bands[band].msb_sample_buffer[k],
+                                        coeff, s->nframesamples);
+                    if (band)
+                        s->dcadsp->dmix_sub(c->deci_history[j],
+                                            o->deci_history[k],
+                                            coeff, DCA_XLL_DECI_HISTORY_MAX);
+                }
+            }
+        }
+
+        nchannels += c->nchannels;
+        if (nchannels >= o->hier_ofs)
+            break;
+    }
+}
+
+static void scale_down_mix(DCAXllDecoder *s, DCAXllChSet *o, int band)
+{
+    int i, j, nchannels = 0;
+    DCAXllChSet *c;
+
+    for (i = 0, c = s->chset; i < s->nactivechsets; i++, c++) {
+        if (!c->hier_chset)
+            continue;
+
+        av_assert1(band < c->nfreqbands);
+        for (j = 0; j < c->nchannels; j++) {
+            int scale = o->dmix_scale[nchannels++];
+            if (scale != (1 << 15)) {
+                s->dcadsp->dmix_scale(c->bands[band].msb_sample_buffer[j],
+                                      scale, s->nframesamples);
+                if (band)
+                    s->dcadsp->dmix_scale(c->deci_history[j],
+                                          scale, DCA_XLL_DECI_HISTORY_MAX);
+            }
+        }
+
+        if (nchannels >= o->hier_ofs)
+            break;
+    }
+}
+
+// Clear all band data and replace non-residual encoded channels with lossy
+// counterparts
+static void av_cold force_lossy_output(DCAXllDecoder *s, DCAXllChSet *c)
+{
+    DCAContext *dca = s->avctx->priv_data;
+    int band, ch;
+
+    for (band = 0; band < c->nfreqbands; band++)
+        chs_clear_band_data(s, c, band, -1);
+
+    for (ch = 0; ch < c->nchannels; ch++) {
+        if (!(c->residual_encode & (1 << ch)))
+            continue;
+        if (ff_dca_core_map_spkr(&dca->core, c->ch_remap[ch]) < 0)
+            continue;
+        c->residual_encode &= ~(1 << ch);
+    }
+}
+
+static int combine_residual_frame(DCAXllDecoder *s, DCAXllChSet *c)
+{
+    DCAContext *dca = s->avctx->priv_data;
+    int ch, nsamples = s->nframesamples;
+    DCAXllChSet *o;
+
+    // Verify that core is compatible
+    if (!(dca->packet & DCA_PACKET_CORE)) {
+        av_log(s->avctx, AV_LOG_ERROR, "Residual encoded channels are present without core\n");
+        return AVERROR(EINVAL);
+    }
+
+    if (c->freq != dca->core.output_rate) {
+        av_log(s->avctx, AV_LOG_WARNING, "Sample rate mismatch between core (%d Hz) and XLL (%d Hz)\n", dca->core.output_rate, c->freq);
+        return AVERROR_INVALIDDATA;
+    }
+
+    if (nsamples != dca->core.npcmsamples) {
+        av_log(s->avctx, AV_LOG_WARNING, "Number of samples per frame mismatch between core (%d) and XLL (%d)\n", dca->core.npcmsamples, nsamples);
+        return AVERROR_INVALIDDATA;
+    }
+
+    // See if this channel set is downmixed and find the next channel set in
+    // hierarchy. If downmixed, undo core pre-scaling before combining with
+    // residual (residual is not scaled).
+    o = find_next_hier_dmix_chset(s, c);
+
+    // Reduce core bit width and combine with residual
+    for (ch = 0; ch < c->nchannels; ch++) {
+        int n, spkr, shift, round;
+        int32_t *src, *dst;
+
+        if (c->residual_encode & (1 << ch))
+            continue;
+
+        // Map this channel to core speaker
+        spkr = ff_dca_core_map_spkr(&dca->core, c->ch_remap[ch]);
+        if (spkr < 0) {
+            av_log(s->avctx, AV_LOG_WARNING, "Residual encoded channel (%d) references unavailable core channel\n", c->ch_remap[ch]);
+            return AVERROR_INVALIDDATA;
+        }
+
+        // Account for LSB width
+        shift = 24 - c->pcm_bit_res + chs_get_lsb_width(s, c, 0, ch);
+        if (shift > 24) {
+            av_log(s->avctx, AV_LOG_WARNING, "Invalid core shift (%d bits)\n", shift);
+            return AVERROR_INVALIDDATA;
+        }
+
+        round = shift > 0 ? 1 << (shift - 1) : 0;
+
+        src = dca->core.output_samples[spkr];
+        dst = c->bands[0].msb_sample_buffer[ch];
+        if (o) {
+            // Undo embedded core downmix pre-scaling
+            int scale_inv = o->dmix_scale_inv[c->hier_ofs + ch];
+            for (n = 0; n < nsamples; n++)
+                dst[n] += clip23((mul16(src[n], scale_inv) + round) >> shift);
+        } else {
+            // No downmix scaling
+            for (n = 0; n < nsamples; n++)
+                dst[n] += (src[n] + round) >> shift;
+        }
+    }
+
+    return 0;
+}
+
+int ff_dca_xll_filter_frame(DCAXllDecoder *s, AVFrame *frame)
+{
+    AVCodecContext *avctx = s->avctx;
+    DCAContext *dca = avctx->priv_data;
+    DCAExssAsset *asset = &dca->exss.assets[0];
+    DCAXllChSet *p = &s->chset[0], *c;
+    enum AVMatrixEncoding matrix_encoding = AV_MATRIX_ENCODING_NONE;
+    int i, j, k, ret, shift, nsamples, request_mask;
+    int ch_remap[DCA_SPEAKER_COUNT];
+
+    // Force lossy downmixed output during recovery
+    if (dca->packet & DCA_PACKET_RECOVERY) {
+        for (i = 0, c = s->chset; i < s->nchsets; i++, c++) {
+            if (i < s->nactivechsets)
+                force_lossy_output(s, c);
+
+            if (!c->primary_chset)
+                c->dmix_embedded = 0;
+        }
+
+        s->scalable_lsbs = 0;
+        s->fixed_lsb_width = 0;
+    }
+
+    // Filter frequency bands for active channel sets
+    s->output_mask = 0;
+    for (i = 0, c = s->chset; i < s->nactivechsets; i++, c++) {
+        chs_filter_band_data(s, c, 0);
+
+        if (c->residual_encode != (1 << c->nchannels) - 1
+            && (ret = combine_residual_frame(s, c)) < 0)
+            return ret;
+
+        if (s->scalable_lsbs)
+            chs_assemble_msbs_lsbs(s, c, 0);
+
+        if (c->nfreqbands > 1) {
+            chs_filter_band_data(s, c, 1);
+            chs_assemble_msbs_lsbs(s, c, 1);
+        }
+
+        s->output_mask |= c->ch_mask;
+    }
+
+    // Undo hierarchial downmix and/or apply scaling
+    for (i = 1, c = &s->chset[1]; i < s->nchsets; i++, c++) {
+        if (!is_hier_dmix_chset(c))
+            continue;
+
+        if (i >= s->nactivechsets) {
+            for (j = 0; j < c->nfreqbands; j++)
+                if (c->bands[j].dmix_embedded)
+                    scale_down_mix(s, c, j);
+            break;
+        }
+
+        for (j = 0; j < c->nfreqbands; j++)
+            if (c->bands[j].dmix_embedded)
+                undo_down_mix(s, c, j);
+    }
+
+    // Assemble frequency bands for active channel sets
+    if (s->nfreqbands > 1) {
+        for (i = 0; i < s->nactivechsets; i++)
+            if ((ret = chs_assemble_freq_bands(s, &s->chset[i])) < 0)
+                return ret;
+    }
+
+    // Normalize to regular 5.1 layout if downmixing
+    if (dca->request_channel_layout) {
+        if (s->output_mask & DCA_SPEAKER_MASK_Lss) {
+            s->output_samples[DCA_SPEAKER_Ls] = s->output_samples[DCA_SPEAKER_Lss];
+            s->output_mask = (s->output_mask & ~DCA_SPEAKER_MASK_Lss) | DCA_SPEAKER_MASK_Ls;
+        }
+        if (s->output_mask & DCA_SPEAKER_MASK_Rss) {
+            s->output_samples[DCA_SPEAKER_Rs] = s->output_samples[DCA_SPEAKER_Rss];
+            s->output_mask = (s->output_mask & ~DCA_SPEAKER_MASK_Rss) | DCA_SPEAKER_MASK_Rs;
+        }
+    }
+
+    // Handle downmixing to stereo request
+    if (dca->request_channel_layout == DCA_SPEAKER_LAYOUT_STEREO
+        && DCA_HAS_STEREO(s->output_mask) && p->dmix_embedded
+        && (p->dmix_type == DCA_DMIX_TYPE_LoRo ||
+            p->dmix_type == DCA_DMIX_TYPE_LtRt))
+        request_mask = DCA_SPEAKER_LAYOUT_STEREO;
+    else
+        request_mask = s->output_mask;
+    if (!ff_dca_set_channel_layout(avctx, ch_remap, request_mask))
+        return AVERROR(EINVAL);
+
+    avctx->sample_rate = p->freq << (s->nfreqbands - 1);
+
+    switch (p->storage_bit_res) {
+    case 16:
+        avctx->sample_fmt = AV_SAMPLE_FMT_S16P;
+        break;
+    case 24:
+        avctx->sample_fmt = AV_SAMPLE_FMT_S32P;
+        break;
+    default:
+        return AVERROR(EINVAL);
+    }
+
+    avctx->bits_per_raw_sample = p->storage_bit_res;
+    avctx->profile = FF_PROFILE_DTS_HD_MA;
+    avctx->bit_rate = 0;
+
+    frame->nb_samples = nsamples = s->nframesamples << (s->nfreqbands - 1);
+    if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)
+        return ret;
+
+    // Downmix primary channel set to stereo
+    if (request_mask != s->output_mask) {
+        ff_dca_downmix_to_stereo_fixed(s->dcadsp, s->output_samples,
+                                       p->dmix_coeff, nsamples,
+                                       s->output_mask);
+    }
+
+    shift = p->storage_bit_res - p->pcm_bit_res;
+    for (i = 0; i < avctx->channels; i++) {
+        int32_t *samples = s->output_samples[ch_remap[i]];
+        if (frame->format == AV_SAMPLE_FMT_S16P) {
+            int16_t *plane = (int16_t *)frame->extended_data[i];
+            for (k = 0; k < nsamples; k++)
+                plane[k] = av_clip_int16(samples[k] * (1 << shift));
+        } else {
+            int32_t *plane = (int32_t *)frame->extended_data[i];
+            for (k = 0; k < nsamples; k++)
+                plane[k] = clip23(samples[k] * (1 << shift)) * (1 << 8);
+        }
+    }
+
+    if (!asset->one_to_one_map_ch_to_spkr) {
+        if (asset->representation_type == DCA_REPR_TYPE_LtRt)
+            matrix_encoding = AV_MATRIX_ENCODING_DOLBY;
+        else if (asset->representation_type == DCA_REPR_TYPE_LhRh)
+            matrix_encoding = AV_MATRIX_ENCODING_DOLBYHEADPHONE;
+    } else if (request_mask != s->output_mask && p->dmix_type == DCA_DMIX_TYPE_LtRt) {
+        matrix_encoding = AV_MATRIX_ENCODING_DOLBY;
+    }
+    if ((ret = ff_side_data_update_matrix_encoding(frame, matrix_encoding)) < 0)
+        return ret;
+
+    return 0;
+}
+
+av_cold void ff_dca_xll_flush(DCAXllDecoder *s)
+{
+    clear_pbr(s);
+}
+
+av_cold void ff_dca_xll_close(DCAXllDecoder *s)
+{
+    DCAXllChSet *c;
+    int i, j;
+
+    for (i = 0, c = s->chset; i < DCA_XLL_CHSETS_MAX; i++, c++) {
+        for (j = 0; j < DCA_XLL_SAMPLE_BUFFERS_MAX; j++) {
+            av_freep(&c->sample_buffer[j]);
+            c->sample_size[j] = 0;
+        }
+    }
+
+    av_freep(&s->navi);
+    s->navi_size = 0;
+
+    av_freep(&s->pbr_buffer);
+    clear_pbr(s);
+}
diff --git a/libavcodec/dca_xll.h b/libavcodec/dca_xll.h
new file mode 100644
index 0000000..bc0aa65
--- /dev/null
+++ b/libavcodec/dca_xll.h
@@ -0,0 +1,149 @@
+/*
+ * 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_XLL_H
+#define AVCODEC_DCA_XLL_H
+
+#include "libavutil/common.h"
+#include "libavutil/mem.h"
+
+#include "avcodec.h"
+#include "internal.h"
+#include "get_bits.h"
+#include "dca.h"
+#include "dcadsp.h"
+#include "dca_exss.h"
+
+#define DCA_XLL_CHSETS_MAX              3
+#define DCA_XLL_CHANNELS_MAX            8
+#define DCA_XLL_BANDS_MAX               2
+#define DCA_XLL_ADAPT_PRED_ORDER_MAX    16
+#define DCA_XLL_DECI_HISTORY_MAX        8
+#define DCA_XLL_DMIX_SCALES_MAX         ((DCA_XLL_CHSETS_MAX - 1) * DCA_XLL_CHANNELS_MAX)
+#define DCA_XLL_DMIX_COEFFS_MAX         (DCA_XLL_DMIX_SCALES_MAX * DCA_XLL_CHANNELS_MAX)
+#define DCA_XLL_PBR_BUFFER_MAX          (240 << 10)
+#define DCA_XLL_SAMPLE_BUFFERS_MAX      3
+
+typedef struct DCAXllBand {
+    int     decor_enabled;                          ///< Pairwise channel decorrelation flag
+    int     orig_order[DCA_XLL_CHANNELS_MAX];       ///< Original channel order
+    int     decor_coeff[DCA_XLL_CHANNELS_MAX / 2];  ///< Pairwise channel coefficients
+
+    int     adapt_pred_order[DCA_XLL_CHANNELS_MAX]; ///< Adaptive predictor order
+    int     highest_pred_order;                     ///< Highest adaptive predictor order
+    int     fixed_pred_order[DCA_XLL_CHANNELS_MAX]; ///< Fixed predictor order
+    int     adapt_refl_coeff[DCA_XLL_CHANNELS_MAX][DCA_XLL_ADAPT_PRED_ORDER_MAX];   ///< Adaptive predictor reflection coefficients
+
+    int     dmix_embedded;  ///< Downmix performed by encoder in frequency band
+
+    int     lsb_section_size;                       ///< Size of LSB section in any segment
+    int     nscalablelsbs[DCA_XLL_CHANNELS_MAX];    ///< Number of bits to represent the samples in LSB part
+    int     bit_width_adjust[DCA_XLL_CHANNELS_MAX]; ///< Number of bits discarded by authoring
+
+    int32_t *msb_sample_buffer[DCA_XLL_CHANNELS_MAX];   ///< MSB sample buffer pointers
+    int32_t *lsb_sample_buffer[DCA_XLL_CHANNELS_MAX];   ///< LSB sample buffer pointers or NULL
+} DCAXllBand;
+
+typedef struct DCAXllChSet {
+    // Channel set header
+    int     nchannels;          ///< Number of channels in the channel set (N)
+    int     residual_encode;    ///< Residual encoding mask (0 - residual, 1 - full channel)
+    int     pcm_bit_res;        ///< PCM bit resolution (variable)
+    int     storage_bit_res;    ///< Storage bit resolution (16 or 24)
+    int     freq;               ///< Original sampling frequency (max. 96000 Hz)
+
+    int     primary_chset;          ///< Primary channel set flag
+    int     dmix_coeffs_present;    ///< Downmix coefficients present in stream
+    int     dmix_embedded;          ///< Downmix already performed by encoder
+    int     dmix_type;              ///< Primary channel set downmix type
+    int     hier_chset;             ///< Whether the channel set is part of a hierarchy
+    int     hier_ofs;               ///< Number of preceding channels in a hierarchy (M)
+    int     dmix_coeff[DCA_XLL_DMIX_COEFFS_MAX];       ///< Downmixing coefficients
+    int     dmix_scale[DCA_XLL_DMIX_SCALES_MAX];       ///< Downmixing scales
+    int     dmix_scale_inv[DCA_XLL_DMIX_SCALES_MAX];   ///< Inverse downmixing scales
+    int     ch_mask;                ///< Channel mask for set
+    int     ch_remap[DCA_XLL_CHANNELS_MAX];    ///< Channel to speaker map
+
+    int     nfreqbands; ///< Number of frequency bands (1 or 2)
+    int     nabits;     ///< Number of bits to read bit allocation coding parameter
+
+    DCAXllBand     bands[DCA_XLL_BANDS_MAX];   ///< Frequency bands
+
+    // Frequency band coding parameters
+    int     seg_common;                                     ///< Segment type
+    int     rice_code_flag[DCA_XLL_CHANNELS_MAX];           ///< Rice coding flag
+    int     bitalloc_hybrid_linear[DCA_XLL_CHANNELS_MAX];   ///< Binary code length for isolated samples
+    int     bitalloc_part_a[DCA_XLL_CHANNELS_MAX];          ///< Coding parameter for part A of segment
+    int     bitalloc_part_b[DCA_XLL_CHANNELS_MAX];          ///< Coding parameter for part B of segment
+    int     nsamples_part_a[DCA_XLL_CHANNELS_MAX];          ///< Number of samples in part A of segment
+
+    // Decimator history
+    DECLARE_ALIGNED(32, int32_t, deci_history)[DCA_XLL_CHANNELS_MAX][DCA_XLL_DECI_HISTORY_MAX]; ///< Decimator history for frequency band 1
+
+    // Sample buffers
+    unsigned int    sample_size[DCA_XLL_SAMPLE_BUFFERS_MAX];
+    int32_t         *sample_buffer[DCA_XLL_SAMPLE_BUFFERS_MAX];
+} DCAXllChSet;
+
+typedef struct DCAXllDecoder {
+    AVCodecContext  *avctx;
+    GetBitContext   gb;
+
+    int     frame_size;             ///< Number of bytes in a lossless frame
+    int     nchsets;                ///< Number of channels sets per frame
+    int     nframesegs;             ///< Number of segments per frame
+    int     nsegsamples_log2;       ///< log2(nsegsamples)
+    int     nsegsamples;            ///< Samples in segment per one frequency band
+    int     nframesamples_log2;     ///< log2(nframesamples)
+    int     nframesamples;          ///< Samples in frame per one frequency band
+    int     seg_size_nbits;         ///< Number of bits used to read segment size
+    int     band_crc_present;       ///< Presence of CRC16 within each frequency band
+    int     scalable_lsbs;          ///< MSB/LSB split flag
+    int     ch_mask_nbits;          ///< Number of bits used to read channel mask
+    int     fixed_lsb_width;        ///< Fixed LSB width
+
+    DCAXllChSet    chset[DCA_XLL_CHSETS_MAX]; ///< Channel sets
+
+    int             *navi;          ///< NAVI table
+    unsigned int    navi_size;
+
+    int     nfreqbands;     ///< Highest number of frequency bands
+    int     nchannels;      ///< Total number of channels in a hierarchy
+    int     nreschsets;     ///< Number of channel sets that have residual encoded channels
+    int     nactivechsets;  ///< Number of active channel sets to decode
+
+    int     hd_stream_id;   ///< Previous DTS-HD stream ID for detecting changes
+
+    uint8_t     *pbr_buffer;        ///< Peak bit rate (PBR) smoothing buffer
+    int         pbr_length;         ///< Length in bytes of data currently buffered
+    int         pbr_delay;          ///< Delay in frames before decoding buffered data
+
+    DCADSPContext   *dcadsp;
+
+    int     output_mask;
+    int32_t *output_samples[DCA_SPEAKER_COUNT];
+} DCAXllDecoder;
+
+int ff_dca_xll_parse(DCAXllDecoder *s, uint8_t *data, DCAExssAsset *asset);
+int ff_dca_xll_filter_frame(DCAXllDecoder *s, AVFrame *frame);
+av_cold void ff_dca_xll_flush(DCAXllDecoder *s);
+av_cold void ff_dca_xll_close(DCAXllDecoder *s);
+
+#endif
-- 
2.1.4



More information about the ffmpeg-devel mailing list