[FFmpeg-devel] [FWD] [PATCH] immediate decoding of dvd stills

Joakim Plate elupus at ecce.se
Tue Jun 21 21:18:22 CEST 2011


Hi,

Bump on OLD OLD issue. Still no knews on this is there? I would love to replace 
libmpeg2 with ffmpeg for dvd video decoding, but this is still a blocker.

At some point since back then, the parser for mpeg video has been changed to 
output the sequence end byte as part of the video packet so a patch like this is 
also required:

diff --git a/libavcodec/mpeg12.c b/libavcodec/mpeg12.c
index bd858a5..3fd68e3 100644
--- a/libavcodec/mpeg12.c
+++ b/libavcodec/mpeg12.c
@@ -2280,7 +2280,7 @@ static int mpeg_decode_frame(AVCodecContext *avctx,
     MpegEncContext *s2 = &s->mpeg_enc_ctx;
     av_dlog(avctx, "fill_buffer\n");
 
-    if (buf_size == 0 || (buf_size == 4 && AV_RB32(buf) == SEQ_END_CODE)) {
+    if (buf_size == 0 || (buf_size >= 4 && AV_RB32(buf+buf_size-4) == 
SEQ_END_CODE)) {
         /* special case for last picture */
         if (s2->low_delay==0 && s2->next_picture_ptr) {
             *picture= *(AVFrame*)s2->next_picture_ptr;


Would something like a bug workaround flag be acceptable to get this given that 
it's fully know it's a dvd with still frames on codec open?

/Joakim






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