Opened 10 years ago

Last modified 9 years ago

#1520 new defect

Start position specified to mencoder with -ss interpreted incorrectly

Reported by: jik@… Owned by: reimar
Priority: normal Component: vd
Version: HEAD Severity: normal
Keywords: Cc: reimar
Blocked By: Blocking:
Reproduced by developer: Analyzed by developer:

Description

I have this file:

ID_AUDIO_ID=1
ID_VIDEO_ID=2
ID_FILENAME=old.wmv
ID_DEMUXER=asf
ID_VIDEO_FORMAT=WMV3
ID_VIDEO_BITRATE=521712
ID_VIDEO_WIDTH=1152
ID_VIDEO_HEIGHT=864
ID_VIDEO_FPS=1000.000
ID_VIDEO_ASPECT=0.0000
ID_AUDIO_FORMAT=353
ID_AUDIO_BITRATE=0
ID_AUDIO_RATE=0
ID_AUDIO_NCH=0
ID_LENGTH=1970.00
ID_SEEKABLE=1
ID_CHAPTERS=0
ID_VIDEO_CODEC=wmv9dmo
ID_AUDIO_BITRATE=48024
ID_AUDIO_RATE=44100
ID_AUDIO_NCH=1
ID_AUDIO_CODEC=ffwmav2
ID_EXIT=EOF

I want to encode it without the first 58 seconds. So I do:

mencoder -ss 58 -oac lavc -ovc lavc -lavcopts vcodec=ffv1 -o new.avi old.wmv

But instead of skipping 59 seconds, it skips to about the middle of the file.

I've tried to figure out exactly how the argument to -ss is being interpreted, and I just can't figure it out.

Change History (3)

comment:1 Changed 10 years ago by john.vansickle@…

(In reply to comment #0)

I have this file:

ID_AUDIO_ID=1
ID_VIDEO_ID=2
ID_FILENAME=old.wmv
ID_DEMUXER=asf
ID_VIDEO_FORMAT=WMV3
ID_VIDEO_BITRATE=521712
ID_VIDEO_WIDTH=1152
ID_VIDEO_HEIGHT=864
ID_VIDEO_FPS=1000.000
ID_VIDEO_ASPECT=0.0000
ID_AUDIO_FORMAT=353
ID_AUDIO_BITRATE=0
ID_AUDIO_RATE=0
ID_AUDIO_NCH=0
ID_LENGTH=1970.00
ID_SEEKABLE=1
ID_CHAPTERS=0
ID_VIDEO_CODEC=wmv9dmo
ID_AUDIO_BITRATE=48024
ID_AUDIO_RATE=44100
ID_AUDIO_NCH=1
ID_AUDIO_CODEC=ffwmav2
ID_EXIT=EOF

I want to encode it without the first 58 seconds. So I do:

mencoder -ss 58 -oac lavc -ovc lavc -lavcopts vcodec=ffv1 -o new.avi old.wmv

But instead of skipping 59 seconds, it skips to about the middle of the file.

I've tried to figure out exactly how the argument to -ss is being interpreted,
and I just can't figure it out.

It's difficult to help without your input file to test against. Upload a sample.

comment:2 Changed 10 years ago by reimar

  • Cc Reimar.Doeffinger@… added

Also try -demuxer lavf, it should at least be different, sometimes more accurate.

comment:3 Changed 9 years ago by compn

  • Owner changed from r_togni@… to reimar
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