[FFmpeg-trac] #786(avformat:new): GXF file frame rate double what it should be for some files.

FFmpeg trac at avcodec.org
Mon Dec 19 23:26:07 CET 2011

#786: GXF file frame rate double what it should be for some files.
             Reporter:  ryaowe      |                    Owner:
                 Type:  defect      |                   Status:  new
             Priority:  normal      |                Component:  avformat
              Version:  git-master  |               Resolution:
             Keywords:              |               Blocked By:
             Blocking:              |  Reproduced by developer:  0
Analyzed by developer:  0           |

Comment (by ryaowe):

 You're brilliant!  It took me a while to prove it to myself, but after
 much effort, it turns out you were spot on from the beginning.

 I bought the spec from the mafia er SMPTE, then wrote enough of a parser
 to verify that avformat was reading header values correctly (I know, silly
 of me, but I had to prove it to myself).

 As you say, the spec indicates that progressive content should only use
 even field numbers.  The field numbers in the files I've been dealing with
 increment by 1.   This would indicate interlaced content, event though

 So either A) the 60fps should really be 30fps and fields_per_frame should
 be 2, or B) the field numbers in the media packets should be only even

 I'll implement the hack you recommended for now, but the right fix is to
 get my content producer to solve the problem on their end.  Thanks for
 your help and patience!

Ticket URL: <https://ffmpeg.org/trac/ffmpeg/ticket/786#comment:7>
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