[FFmpeg-devel] lavc/g729dec: Support stereo streams

From 64114575e9015608c0266df5a6339f526e9dd233 Mon Sep 17 00:00:00 2001
From: Carl Eugen Hoyos <ceffmpeg@gmail.com>
Date: Wed, 12 Dec 2018 23:19:59 +0100
Subject: [PATCH] lavc/g729dec: Support stereo streams.

Fixes ticket #4553.
---
 libavcodec/g729_parser.c |    1 +
 libavcodec/g729dec.c     |   30 ++++++++++++++++++++----------
 2 files changed, 21 insertions(+), 10 deletions(-)

diff --git a/libavcodec/g729_parser.c b/libavcodec/g729_parser.c
index d13c990..9982dbf 100644
--- a/libavcodec/g729_parser.c
+++ b/libavcodec/g729_parser.c
@@ -48,6 +48,7 @@  static int g729_parse(AVCodecParserContext *s1, AVCodecContext *avctx,
         av_assert1(avctx->codec_id == AV_CODEC_ID_G729);
         /* FIXME: replace this heuristic block_size with more precise estimate */
         s->block_size = (avctx->bit_rate < 8000) ? G729D_6K4_BLOCK_SIZE : G729_8K_BLOCK_SIZE;
+        s->block_size *= avctx->channels;
         s->duration   = avctx->frame_size;
     }
 
diff --git a/libavcodec/g729dec.c b/libavcodec/g729dec.c
index 2e1bf18..d27ab51 100644
--- a/libavcodec/g729dec.c
+++ b/libavcodec/g729dec.c
@@ -339,17 +339,18 @@  static int32_t scalarproduct_int16_c(const int16_t * v1, const int16_t * v2, int
 static av_cold int decoder_init(AVCodecContext * avctx)
 {
     G729Context* ctx = avctx->priv_data;
-    int i,k;
+    int c,i,k;
 
-    if (avctx->channels != 1) {
-        av_log(avctx, AV_LOG_ERROR, "Only mono sound is supported (requested channels: %d).\n", avctx->channels);
+    if (avctx->channels > 2) {
+        av_log(avctx, AV_LOG_ERROR, "Only mono and stereo are supported (requested channels: %d).\n", avctx->channels);
         return AVERROR(EINVAL);
     }
-    avctx->sample_fmt = AV_SAMPLE_FMT_S16;
+    avctx->sample_fmt = AV_SAMPLE_FMT_S16P;
 
     /* Both 8kbit/s and 6.4kbit/s modes uses two subframes per frame. */
     avctx->frame_size = SUBFRAME_SIZE << 1;
 
+    for (c = 0; c < avctx->channels; c++) {
     ctx->gain_coeff = 16384; // 1.0 in (1.14)
 
     for (k = 0; k < MA_NP + 1; k++) {
@@ -376,6 +377,9 @@  static av_cold int decoder_init(AVCodecContext * avctx)
     ff_audiodsp_init(&ctx->adsp);
     ctx->adsp.scalarproduct_int16 = scalarproduct_int16_c;
 
+    ctx++;
+    }
+
     return 0;
 }
 
@@ -389,7 +393,7 @@  static int decode_frame(AVCodecContext *avctx, void *data, int *got_frame_ptr,
     const G729FormatDescription *format;
     int frame_erasure = 0;    ///< frame erasure detected during decoding
     int bad_pitch = 0;        ///< parity check failed
-    int i;
+    int c, i;
     int16_t *tmp;
     G729Formats packet_type;
     G729Context *ctx = avctx->priv_data;
@@ -411,16 +415,15 @@  static int decode_frame(AVCodecContext *avctx, void *data, int *got_frame_ptr,
     frame->nb_samples = SUBFRAME_SIZE<<1;
     if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)
         return ret;
-    out_frame = (int16_t*) frame->data[0];
 
-    if (buf_size % 10 == 0) {
+    if (buf_size % G729_8K_BLOCK_SIZE * avctx->channels == 0) {
         packet_type = FORMAT_G729_8K;
         format = &format_g729_8k;
         //Reset voice decision
         ctx->onset = 0;
         ctx->voice_decision = DECISION_VOICE;
         av_log(avctx, AV_LOG_DEBUG, "Packet type: %s\n", "G.729 @ 8kbit/s");
-    } else if (buf_size == 8) {
+    } else if (buf_size == G729D_6K4_BLOCK_SIZE * avctx->channels) {
         packet_type = FORMAT_G729D_6K4;
         format = &format_g729d_6k4;
         av_log(avctx, AV_LOG_DEBUG, "Packet type: %s\n", "G.729D @ 6.4kbit/s");
@@ -429,6 +432,9 @@  static int decode_frame(AVCodecContext *avctx, void *data, int *got_frame_ptr,
         return AVERROR_INVALIDDATA;
     }
 
+    for (c = 0; c < avctx->channels; c++) {
+    out_frame = (int16_t*)frame->data[c];
+
     for (i=0; i < buf_size; i++)
         frame_erasure |= buf[i];
     frame_erasure = !frame_erasure;
@@ -702,8 +708,12 @@  static int decode_frame(AVCodecContext *avctx, void *data, int *got_frame_ptr,
     /* Save signal for use in next frame. */
     memmove(ctx->exc_base, ctx->exc_base + 2 * SUBFRAME_SIZE, (PITCH_DELAY_MAX+INTERPOL_LEN)*sizeof(int16_t));
 
+    buf += packet_type == FORMAT_G729_8K ? G729_8K_BLOCK_SIZE : G729D_6K4_BLOCK_SIZE;
+    ctx++;
+    }
+
     *got_frame_ptr = 1;
-    return packet_type == FORMAT_G729_8K ? 10 : 8;
+    return packet_type == FORMAT_G729_8K ? G729_8K_BLOCK_SIZE * avctx->channels : G729D_6K4_BLOCK_SIZE * avctx->channels;
 }
 
 AVCodec ff_g729_decoder = {
@@ -711,7 +721,7 @@  AVCodec ff_g729_decoder = {
     .long_name      = NULL_IF_CONFIG_SMALL("G.729"),
     .type           = AVMEDIA_TYPE_AUDIO,
     .id             = AV_CODEC_ID_G729,
-    .priv_data_size = sizeof(G729Context),
+    .priv_data_size = sizeof(G729Context) * 2,
     .init           = decoder_init,
     .decode         = decode_frame,
     .capabilities   = AV_CODEC_CAP_SUBFRAMES | AV_CODEC_CAP_DR1,
-- 
1.7.10.4