[FFmpeg-devel] [PATCH] lavc: remove the QOA decoder

Anton Khirnov anton at khirnov.net
Sat Dec 2 17:53:52 EET 2023


Its author not only failed to add any tests, as is required by the
development rules, but continues to actively refuse to do so.

Untested decoders are worse than useless, so remove it.
---
 Changelog              |   2 +-
 libavcodec/Makefile    |   1 -
 libavcodec/allcodecs.c |   1 -
 libavcodec/qoadec.c    | 170 -----------------------------------------
 4 files changed, 1 insertion(+), 173 deletions(-)
 delete mode 100644 libavcodec/qoadec.c

diff --git a/Changelog b/Changelog
index f00bc27ca4..3d3b079089 100644
--- a/Changelog
+++ b/Changelog
@@ -5,7 +5,7 @@ version <next>:
 - LEAD MCMP decoder
 - EVC decoding using external library libxevd
 - EVC encoding using external library libxeve
-- QOA decoder and demuxer
+- QOA demuxer
 - aap filter
 
 version 6.1:
diff --git a/libavcodec/Makefile b/libavcodec/Makefile
index 748806e702..a5941d1284 100644
--- a/libavcodec/Makefile
+++ b/libavcodec/Makefile
@@ -623,7 +623,6 @@ OBJS-$(CONFIG_QCELP_DECODER)           += qcelpdec.o                     \
 OBJS-$(CONFIG_QDM2_DECODER)            += qdm2.o
 OBJS-$(CONFIG_QDMC_DECODER)            += qdmc.o
 OBJS-$(CONFIG_QDRAW_DECODER)           += qdrw.o
-OBJS-$(CONFIG_QOA_DECODER)             += qoadec.o
 OBJS-$(CONFIG_QOI_DECODER)             += qoidec.o
 OBJS-$(CONFIG_QOI_ENCODER)             += qoienc.o
 OBJS-$(CONFIG_QPEG_DECODER)            += qpeg.o
diff --git a/libavcodec/allcodecs.c b/libavcodec/allcodecs.c
index b0f004e15c..87595683f9 100644
--- a/libavcodec/allcodecs.c
+++ b/libavcodec/allcodecs.c
@@ -522,7 +522,6 @@ extern const FFCodec ff_paf_audio_decoder;
 extern const FFCodec ff_qcelp_decoder;
 extern const FFCodec ff_qdm2_decoder;
 extern const FFCodec ff_qdmc_decoder;
-extern const FFCodec ff_qoa_decoder;
 extern const FFCodec ff_ra_144_encoder;
 extern const FFCodec ff_ra_144_decoder;
 extern const FFCodec ff_ra_288_decoder;
diff --git a/libavcodec/qoadec.c b/libavcodec/qoadec.c
deleted file mode 100644
index 443f42a527..0000000000
--- a/libavcodec/qoadec.c
+++ /dev/null
@@ -1,170 +0,0 @@
-/*
- * QOA decoder
- *
- * 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 "avcodec.h"
-#include "codec_internal.h"
-#include "decode.h"
-#include "get_bits.h"
-#include "bytestream.h"
-#include "mathops.h"
-
-#define QOA_SLICE_LEN 20
-#define QOA_LMS_LEN 4
-
-typedef struct QOAChannel {
-    int history[QOA_LMS_LEN];
-    int weights[QOA_LMS_LEN];
-} QOAChannel;
-
-typedef struct QOAContext {
-    QOAChannel ch[256];
-} QOAContext;
-
-static const int16_t qoa_dequant_tab[16][8] = {
-    {   1,    -1,    3,    -3,    5,    -5,     7,     -7},
-    {   5,    -5,   18,   -18,   32,   -32,    49,    -49},
-    {  16,   -16,   53,   -53,   95,   -95,   147,   -147},
-    {  34,   -34,  113,  -113,  203,  -203,   315,   -315},
-    {  63,   -63,  210,  -210,  378,  -378,   588,   -588},
-    { 104,  -104,  345,  -345,  621,  -621,   966,   -966},
-    { 158,  -158,  528,  -528,  950,  -950,  1477,  -1477},
-    { 228,  -228,  760,  -760, 1368, -1368,  2128,  -2128},
-    { 316,  -316, 1053, -1053, 1895, -1895,  2947,  -2947},
-    { 422,  -422, 1405, -1405, 2529, -2529,  3934,  -3934},
-    { 548,  -548, 1828, -1828, 3290, -3290,  5117,  -5117},
-    { 696,  -696, 2320, -2320, 4176, -4176,  6496,  -6496},
-    { 868,  -868, 2893, -2893, 5207, -5207,  8099,  -8099},
-    {1064, -1064, 3548, -3548, 6386, -6386,  9933,  -9933},
-    {1286, -1286, 4288, -4288, 7718, -7718, 12005, -12005},
-    {1536, -1536, 5120, -5120, 9216, -9216, 14336, -14336},
-};
-
-static av_cold int qoa_decode_init(AVCodecContext *avctx)
-{
-    avctx->sample_fmt = AV_SAMPLE_FMT_S16;
-
-    return 0;
-}
-
-static int qoa_lms_predict(QOAChannel *lms)
-{
-    int prediction = 0;
-    for (int i = 0; i < QOA_LMS_LEN; i++)
-        prediction += lms->weights[i] * lms->history[i];
-    return prediction >> 13;
-}
-
-static void qoa_lms_update(QOAChannel *lms, int sample, int residual)
-{
-    int delta = residual >> 4;
-    for (int i = 0; i < QOA_LMS_LEN; i++)
-        lms->weights[i] += lms->history[i] < 0 ? -delta : delta;
-    for (int i = 0; i < QOA_LMS_LEN-1; i++)
-        lms->history[i] = lms->history[i+1];
-    lms->history[QOA_LMS_LEN-1] = sample;
-}
-
-static int qoa_decode_frame(AVCodecContext *avctx, AVFrame *frame,
-                            int *got_frame_ptr, AVPacket *avpkt)
-{
-    QOAContext *s = avctx->priv_data;
-    int ret, frame_size, nb_channels, sample_rate;
-    GetByteContext gb;
-    int16_t *samples;
-
-    bytestream2_init(&gb, avpkt->data, avpkt->size);
-
-    nb_channels = bytestream2_get_byte(&gb);
-    sample_rate = bytestream2_get_be24(&gb);
-    if (!sample_rate || !nb_channels)
-        return AVERROR_INVALIDDATA;
-
-    if (nb_channels != avctx->ch_layout.nb_channels) {
-        av_channel_layout_uninit(&avctx->ch_layout);
-        av_channel_layout_default(&avctx->ch_layout, nb_channels);
-        if ((ret = av_channel_layout_copy(&frame->ch_layout, &avctx->ch_layout)) < 0)
-            return ret;
-    }
-
-    frame->sample_rate = avctx->sample_rate = sample_rate;
-
-    frame->nb_samples = bytestream2_get_be16(&gb);
-    frame_size = bytestream2_get_be16(&gb);
-    if (frame_size > avpkt->size)
-        return AVERROR_INVALIDDATA;
-
-    if (frame_size < 8 + QOA_LMS_LEN * 4 * nb_channels +
-        8LL * frame->nb_samples * nb_channels / QOA_SLICE_LEN)
-        return AVERROR_INVALIDDATA;
-
-    if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)
-        return ret;
-    samples = (int16_t *)frame->data[0];
-
-    for (int ch = 0; ch < nb_channels; ch++) {
-        QOAChannel *qch = &s->ch[ch];
-
-        for (int n = 0; n < QOA_LMS_LEN; n++)
-            qch->history[n] = sign_extend(bytestream2_get_be16u(&gb), 16);
-        for (int n = 0; n < QOA_LMS_LEN; n++)
-            qch->weights[n] = sign_extend(bytestream2_get_be16u(&gb), 16);
-    }
-
-    for (int sample_index = 0; sample_index < frame->nb_samples * nb_channels;
-         sample_index += QOA_SLICE_LEN) {
-        for (int ch = 0; ch < nb_channels; ch++) {
-            QOAChannel *lms = &s->ch[ch];
-            uint64_t slice = bytestream2_get_be64u(&gb);
-            int scalefactor = (slice >> 60) & 0xf;
-            int slice_start = sample_index * nb_channels + ch;
-            int slice_end = av_clip(sample_index + QOA_SLICE_LEN, 0, frame->nb_samples) * nb_channels + ch;
-
-            for (int si = slice_start; si < slice_end; si += nb_channels) {
-                int predicted = qoa_lms_predict(lms);
-                int quantized = (slice >> 57) & 0x7;
-                int dequantized = qoa_dequant_tab[scalefactor][quantized];
-                int reconstructed = av_clip_int16(predicted + dequantized);
-
-                samples[si] = reconstructed;
-                slice <<= 3;
-
-                qoa_lms_update(lms, reconstructed, dequantized);
-            }
-        }
-    }
-
-    *got_frame_ptr = 1;
-
-    return avpkt->size;
-}
-
-const FFCodec ff_qoa_decoder = {
-    .p.name         = "qoa",
-    CODEC_LONG_NAME("QOA (Quite OK Audio)"),
-    .p.type         = AVMEDIA_TYPE_AUDIO,
-    .p.id           = AV_CODEC_ID_QOA,
-    .priv_data_size = sizeof(QOAContext),
-    .init           = qoa_decode_init,
-    FF_CODEC_DECODE_CB(qoa_decode_frame),
-    .p.capabilities = AV_CODEC_CAP_CHANNEL_CONF |
-                      AV_CODEC_CAP_DR1,
-    .p.sample_fmts  = (const enum AVSampleFormat[]) { AV_SAMPLE_FMT_S16,
-                                                      AV_SAMPLE_FMT_NONE },
-};
-- 
2.42.0



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