avformat: add support to force specific AVCodecs

previously only codec_ids could be forced, which did not allow
forcing a specific implementation like libopenjpeg vs jpeg2000.

Reviewed-by: Paul B Mahol <onemda@gmail.com>
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

1 files changed, 15 insertions, 0 deletions

diff --git a/libavformat/utils.c b/libavformat/utils.c
index b47787a8ee..61405d7c97 100644
--- a/libavformat/utils.c
+++ b/libavformat/utils.c
@@ -98,12 +98,27 @@ static int64_t wrap_timestamp(AVStream *st, int64_t timestamp)
 }
 
 MAKE_ACCESSORS(AVStream, stream, AVRational, r_frame_rate)
+MAKE_ACCESSORS(AVFormatContext, format, AVCodec *, video_codec)
+MAKE_ACCESSORS(AVFormatContext, format, AVCodec *, audio_codec)
+MAKE_ACCESSORS(AVFormatContext, format, AVCodec *, subtitle_codec)
 
 static AVCodec *find_decoder(AVFormatContext *s, AVStream *st, enum AVCodecID codec_id)
 {
     if (st->codec->codec)
         return st->codec->codec;
 
+    switch(st->codec->codec_type){
+    case AVMEDIA_TYPE_VIDEO:
+        if(s->video_codec)    return s->video_codec;
+        break;
+    case AVMEDIA_TYPE_AUDIO:
+        if(s->audio_codec)    return s->audio_codec;
+        break;
+    case AVMEDIA_TYPE_SUBTITLE:
+        if(s->subtitle_codec) return s->subtitle_codec;
+        break;
+    }
+
     return avcodec_find_decoder(codec_id);
 }