[FFmpeg-trac] #9320(undetermined:new): mpeg2video can't be TFF with progressive source

FFmpeg trac at avcodec.org
Tue Jul 27 21:51:15 EEST 2021

#9320: mpeg2video can't be TFF with progressive source
             Reporter:  Paul         |                    Owner:  (none)
  Pacifico                           |
                 Type:  defect       |                   Status:  new
             Priority:  normal       |                Component:
                                     |  undetermined
              Version:  git-master   |               Resolution:
             Keywords:  mpeg2video   |               Blocked By:
             Blocking:               |  Reproduced by developer:  0
Analyzed by developer:  0            |
Comment (by jeeb):

 Alright, that's unfortunate. Then the only remaining block that was moved
 in my commits which improved ffmpeg.c's passing of input frame metadata
 was the following. You may test with it removed, but I would be surprised
 if that would change the result:
 diff --git a/fftools/ffmpeg.c b/fftools/ffmpeg.c
 index b0ce7c7c32..45949202a7 100644
 --- a/fftools/ffmpeg.c
 +++ b/fftools/ffmpeg.c
 @@ -3485,10 +3485,6 @@ static int init_output_stream_encode(OutputStream
 *ost, AVFrame *frame)

          // Field order: autodetection
          if (frame) {
 -            if (enc_ctx->flags & (AV_CODEC_FLAG_INTERLACED_DCT |
 -                ost->top_field_first >= 0)
 -                frame->top_field_first = !!ost->top_field_first;
              if (frame->interlaced_frame) {
                  if (enc_ctx->codec->id == AV_CODEC_ID_MJPEG)
                      enc_ctx->field_order = frame->top_field_first ?


 Otherwise, the issue would have to be [https://git-scm.com/docs/git-bisect
 bisected], although unfortunately one would have to apply the `-top` fix
 on top when testing commits after my ffmpeg.c rework set.

 As a silver lining, at the very least specifically utilizing `setfield`
 video filter does lead to the right result thanks to that autodetection
 based on input frame metadata I added :) .
Ticket URL: <https://trac.ffmpeg.org/ticket/9320#comment:12>
FFmpeg <https://ffmpeg.org>
FFmpeg issue tracker

More information about the FFmpeg-trac mailing list