[FFmpeg-trac] #1866(undetermined:new): Half speed video output ts -> flv transcode

FFmpeg trac at avcodec.org
Tue Oct 30 11:33:03 CET 2012


#1866: Half speed video output ts -> flv transcode
----------------------------------+----------------------------------------
             Reporter:  larvalho  |                    Owner:
                 Type:  defect    |                   Status:  new
             Priority:  normal    |                Component:  undetermined
              Version:  1.0       |               Resolution:
             Keywords:            |               Blocked By:
             Blocking:            |  Reproduced by developer:  0
Analyzed by developer:  0         |
----------------------------------+----------------------------------------

Comment (by larvalho):

 Replying to [comment:1 cehoyos]:
 > I am not sure I understand:
 > Is the original file supposed to play (ie with video and audio)?
 > Or is the 10 minute delay intentional?
 > In the first case, I would suspect this is a duplicate of ticket #424,
 in the second case, I wonder how ffmpeg is supposed to transcode the
 stream? Shouldn't it try hard to eliminate the A/V desync (leading to slow
 or fast video)?
 The original file does play in VLC, etc. without the delay, and with audio
 correctly in sync.  The 10 minute delay is not intentional, though it is
 indicated in the above output:
 {{{
 Input #0, mpegts, from 'CAPTURE-HD2959dd_1970-01-02_01_26_49.ts':
   Duration: 00:00:24.57, start: 599.983333, bitrate: 2824 kb/s
 }}}
 And with 'mediainfo -f':
 {{{
 Video
 Delay                            : 599983.333
 Delay                            : 9mn 59s
 Delay                            : 9mn 59s 983ms
 Delay                            : 9mn 59s
 Delay                            : 00:09:59.983
 Delay_Source                     : Container

 Audio
 Delay                            : 600047.333
 Delay                            : 10mn 0s
 Delay                            : 10mn 0s 47ms
 Delay                            : 10mn 0s
 Delay                            : 00:10:00.047
 Delay_Source                     : Container
 Video delay                      : 64
 Video delay                      : 64ms
 Video delay                      : 64ms
 Video delay                      : 64ms
 Video delay                      : 00:00:00.064
 Video0 delay                     : 64
 Video0 delay                     : 64ms
 Video0 delay                     : 64ms
 Video0 delay                     : 64ms
 Video0 delay                     : 00:00:00.064

 }}}
 So I suppose it should be honoured.

 If I discard the audio when transcoding (-an), I get the same half speed
 video.

 On another note, running the same file through ffmpegX (using a
 particularly old version of ffmpeg) and HandBrake on OS X, I get no delay
 and correctly synced (normal speed) video and audio.

-- 
Ticket URL: <https://ffmpeg.org/trac/ffmpeg/ticket/1866#comment:2>
FFmpeg <http://ffmpeg.org>
FFmpeg issue tracker


More information about the FFmpeg-trac mailing list