[MEncoder-users] -vf crop causing encode failure?

[Alex Bennee]

Hi,

I've run into an interesting problem with -vf crop. I used to use the
crop detection algorithm with mplayer to determine the correct
parameters. However recently I was ending up with empty video files
(they contained sound but the video stream was black). I've narrowed
the problem down to the use of -vf crop. The following worked:

/usr/bin/mencoder /home/alex/tmp/MASH_THE_MOVIE-1/MASH_THE_MOVIE-1.vob
-ovc x264 -oac copy -x264encopts
subq=6:bframes=3:partitions=p8x8,b8x8,i4x4:weight_b:threads=1:nopsnr:nossim:frameref=3:mixed_refs:level_idc=41:direct_pred=auto:trellis=1:bitrate=2000:pass=1:turbo=1
-o /home/alex/tmp/MASH_THE_MOVIE-1/MASH_THE_MOVIE-1.vob.TURBO.AVI

But adding any setting for vf crop generates the bad encode:

/usr/bin/mencoder /home/alex/tmp/MASH_THE_MOVIE-1/MASH_THE_MOVIE-1.vob
-ovc x264 -oac copy -vf crop=714:448:0:64 -x264encopts
subq=6:bframes=3:partitions=p8x8,b8x8,i4x4:weight_b:threads=1:nopsnr:nossim:frameref=3:mixed_refs:level_idc=41:direct_pred=auto:trellis=1:bitrate=2000:pass=1:turbo=1
-o /home/alex/tmp/MASH_THE_MOVIE-1/MASH_THE_MOVIE-1.vob.TURBO.AVI

Is this a know bug? I'm running mplayer version:

20:30 alex at danny/x86_64 [MASH_THE_MOVIE-1] >mencoder
MEncoder SVN-r30554-4.3.4 (C) 2000-2010 MPlayer Team

On a gentoo system, I can build later versions if required but I
believe that version is Gentoo's current "unstable" build.

-- 
Alex, homepage: http://www.bennee.com/~alex/
http://www.half-llama.co.uk