[MPlayer-users] edl accuracy in mplayer vs. mencoder

[pfile at pacbell.net]

On Dec 26, 2005, at 2:34 PM, mplayer-users-request at mplayerhq.hu wrote:

> You cannot do accurate editing with -ovc copy unless you use a codec
> where all frames are keyframes. Also I recommend using the
> -hr-edl-seek option with mencoder. And make sure your edl file has the
> exact timestamps you want to cut at, not whatever adjusted values work
> well for mplayer -edl (which is imprecise).
>
> Rich
>

i dug into this a little more and... GOTO considered harmful :)

i instrumented the code in mencoder that's doing the EDL skips and 
found that there were two skips for every entry in my cutlist. there's 
a goto at the bottom of the EDL code that goes around and ends up 
calling edl_seek() again. there is a comment above the goto that's 
pretty cryptic, so i'm not sure exactly what case this was supposed to 
handle, but if it was to enforce keyframes its being too strict, as 
there are many more keyframes near my edit point than the one it ends 
on on the 2nd call to edl_seek().

anyway, removing that goto has given me more accurate edits, to the 
point that i dont think i'll need to use avidemux. i'll have to try 
this on more examples to make sure its really solid. maybe someone can 
enlighten me about the need to call edl_seek() twice.

rob