[FFmpeg-devel] [RFC] stream parsing

[Michael Niedermayer]

On Mon, Sep 27, 2010 at 01:17:40AM +0200, Benjamin Larsson wrote:
> 
> >> -static int has_codec_parameters(AVCodecContext *enc)
> >> +static int has_codec_parameters(AVCodecContext *enc, AVCodec *codec)
> >>  {
> >>      int val;
> >>      switch(enc->codec_type) {
> >>      case AVMEDIA_TYPE_AUDIO:
> >>          val = enc->sample_rate && enc->channels && enc->sample_fmt != SAMPLE_FMT_NONE;
> >> +        /* Some containers report wrong information about channel configuration
> >> +         * let the codecs handle it in those cases (dca for example)).
> >> +         */
> >> +        if (codec && codec->capabilities & CODEC_CAP_CHANNEL_CONF) {
> >> +            enc->sample_rate    = 0;
> >> +            enc->channel_layout = 0;
> >> +            enc->frame_size     = 0;
> >> +            enc->channels       = 0;
> >> +            return 0;
> >> +        }
> > 
> > av_find_stream_info() will return once all streams has_codec_parameters()
> > return non zero
> > this explicitly returns 0 unconditional on any parameters being available or
> > not thus has_codec_parameters() will never return non zero for an affected
> > stream, leading to exit only by bug and time/pos limits
> 
> codec is always NULL in the for(;;) block. Thus this code will only be
> triggered once.

i have to maintain this code, and this patch is a huge convoluted hack
passing NULL instead of the correct AVCodec to make the code not end in a
near infinite loop is just crazy

Please tell me if this works:
@@ -2000,6 +2000,8 @@
     int val;
     switch(enc->codec_type) {
     case AVMEDIA_TYPE_AUDIO:
+        if(!enc->channel_layout && (!enc->codec || (enc->codec->capabilities & CODEC_CAP_CHANNEL_CONF)))
+            return 0;
         val = enc->sample_rate && enc->channels && enc->sample_fmt != SAMPLE_FMT_NONE;
         if(!enc->frame_size &&
            (enc->codec_id == CODEC_ID_VORBIS ||

if not, please tell me why it fails, ill fix it

[...]
-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

There will always be a question for which you do not know the correct awnser.
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