[MEncoder-users] Edit Decision List - exact frame cut problem.

[Bill Crockett]

On 12/12/2011 11:50 PM, Ian Collier wrote:
> On Fri, Dec 09, 2011 at 04:41:01PM +1100, you wrote:
>> I am trying to remove advertisements from an MPEG-TS video
> "dvbcut" is meant to be able to do this by only re-encoding the frames
> directly surrounding the cut(s), but (a) I haven't tried it properly,
> and (b) it looks quite old (though rpmfusion currently offers packages
> based on svn rev 178 which is somewhat newer than the last released
> version).

Ian, thanks for putting me on to this DVBcut thing and sorry for the 
delay.  I downloaded it tried it out and It really does the job very 
well.  The best thing; it keeps the audio and video synchronised exactly.

With MEncoder, the exact frame cut problem paled into insignificance 
compared to the audio / video sync problems I was having with the Edit 
Decision List option.  I then tried a different approach, and used the 
-ss and -endpos to cut out the advertisements.  For a 2 hour video, I 
had about 12 to 15 cut sections that had to be concatenated back into 
one video.  Unfortunately, the A / V sync problem surfaced again and was 
pretty bad.  Using MPlayer and the step key, I could get this back in 
sync with scenes of gunshots or the sound of some object hitting 
something, and then use -mpegopts vdelay=??? in MEncoder.  This was time 
consuming and got pretty weary.

There must be some A / V sync problem / bug when encoding or copying 
MPEG-TS videos to MPEG-PS with MEncoder.  I even tried an MPEG-TS with 
FFmpeg, and that produced and out of sync video with the sound.  DVBcut 
seems to be the only one that works.