[MPlayer-users] Cutting DVD video with the '-sb' and '-endpos' options

[Jonathan Busby]

RC wrote:
> On Sun, 22 Mar 2009 13:53:12 -0500
> Jonathan Busby <jonathanbusby at gmail.com> wrote:
>
>   
>> Hello. I have been trying to find a way to cut, with single frame
>> accuracy, an MPEG-2 PS stream from a DVD. 
>>     
>
> You can't get greater than GOP/Keyframe accuracy without reencoding at
> least part of the video stream (which Avidemux does).  End of story.
>   

Yes, I know. The beginning of the cut I know to be on an keyframe
boundary, although the end is not.

> MEncoder does happen to have the -hr-edl-seek option, however, which
> will do more or less what you want as you reencode the video.
>
>   

Thanks for the tip. :)

I've now used Mplayer with the '-edlout' option to generate a cut
list and indeed the time values recorded by pressing 'i' are frame
accurate, or so I thought. I used said cut list with the '-edl' and
'-hr-edl-seek' and a modified encoding script to run a test encode
using Mencoder. Unfortunately the part(s) of the source video
that I marked to be encoded using Mplayer with '-edlout' , 'i' and
'.' for frame-stepping do not correspond ( after editing the cut list
so that eg. 'A B 0\n C D 0\n' is changed to '0 A 0\n B C 0\n D
END_OF_FILE 0\n'
ie. the start and end cut point pairs now correspond to to streams
of video that are *exclusively saved* .
) to the part(s) encoded in the output video.

I've repeated the above only to get the same *exact* results -- the
timestamps produced by pressing 'i' with the '-edlout' option using
Mplayer do not correspond to *absolute* timestamps. That is,
whenever there is a progressive<->interlaced transition in the
source video that results in a frame rate change the video timestamps
often get skewed eg. either by being reset, or jumping backwards.

So, unless I'm missing something really obvious, it seems that the
utility of using Mplayer as a cutting tool for non-progressive video
is nil.

I really don't know what to do now.


Jonathan