[SCM] libav/experimental: Add the CODEC_CAP_CHANNEL_CONF capability code and add that flag to the dca codec. This capability when set will make sure the codec will initialize the channel configuration instead of trusting the container. This fixes issue 2137 and issue 850.

[siretart at users.alioth.debian.org]

The following commit has been merged in the experimental branch:
commit 62784e3733ceb0f58007db8bb2e41e1abf62b85e
Author: Benjamin Larsson <banan at ludd.ltu.se>
Date:   Sat Oct 2 22:18:02 2010 +0000

    Add the CODEC_CAP_CHANNEL_CONF capability code and add
    that flag to the dca codec. This capability when set
    will make sure the codec will initialize the channel
    configuration instead of trusting the container. This
    fixes issue 2137 and issue 850.
    
    Originally committed as revision 25320 to svn://svn.ffmpeg.org/ffmpeg/trunk

diff --git a/libavcodec/avcodec.h b/libavcodec/avcodec.h
index eee5635..4bddbaa 100644
--- a/libavcodec/avcodec.h
+++ b/libavcodec/avcodec.h
@@ -703,6 +703,11 @@ typedef struct RcOverride{
  * encoders
  */
 #define CODEC_CAP_EXPERIMENTAL     0x0200
+/**
+ * Codec should fill in channel configuration and samplerate instead of container
+ */
+#define CODEC_CAP_CHANNEL_CONF     0x0400
+
 
 //The following defines may change, don't expect compatibility if you use them.
 #define MB_TYPE_INTRA4x4   0x0001
diff --git a/libavcodec/dca.c b/libavcodec/dca.c
index e8627a2..afd55bb 100644
--- a/libavcodec/dca.c
+++ b/libavcodec/dca.c
@@ -1500,4 +1500,5 @@ AVCodec dca_decoder = {
     .decode = dca_decode_frame,
     .close = dca_decode_end,
     .long_name = NULL_IF_CONFIG_SMALL("DCA (DTS Coherent Acoustics)"),
+    .capabilities = CODEC_CAP_CHANNEL_CONF,
 };
diff --git a/libavformat/utils.c b/libavformat/utils.c
index 24dbd88..5985511 100644
--- a/libavformat/utils.c
+++ b/libavformat/utils.c
@@ -2167,6 +2167,7 @@ int av_find_stream_info(AVFormatContext *ic)
     } info[MAX_STREAMS] = {{0}};
 
     for(i=0;i<ic->nb_streams;i++) {
+        AVCodec *codec;
         st = ic->streams[i];
         if (st->codec->codec_id == CODEC_ID_AAC) {
             st->codec->sample_rate = 0;
@@ -2187,9 +2188,17 @@ int av_find_stream_info(AVFormatContext *ic)
             }
         }
         assert(!st->codec->codec);
+        codec = avcodec_find_decoder(st->codec->codec_id);
+
+        /* Force decoding of at least one frame of codec data
+         * this makes sure the codec initializes the channel configuration
+         * and does not trust the values from the container.
+         */
+        if (codec && codec->capabilities & CODEC_CAP_CHANNEL_CONF)
+            st->codec->channels = 0;
+
         //try to just open decoders, in case this is enough to get parameters
         if(!has_codec_parameters(st->codec)){
-            AVCodec *codec = avcodec_find_decoder(st->codec->codec_id);
             if (codec)
                 avcodec_open(st->codec, codec);
         }

-- 
Libav/FFmpeg packaging