Issue Appending Video after re encoding a small section of it

[reeso3000]

I have got a few Mkv's with a 30 second watermark in the middle of the video and rather than use delogo on the whole film and re-encode I thought a better option would be to cut the 30 second clip delogo (changing video output to mpeg4 avc x264 and using the filter) and then append the video files back together, I have select "copy" for output and container as mkv(also tried mp4) and the 30 second clip is just random colours in the file created (though it looks fine in avidemux). Can someone tell me what I am doing wrong? or if its even possible to do this with part of the file re encoded (though using mediainfo the codec,frame rate etc is all the same).

Any advise would be greatly appreciated thank you in advance

[zakk]

and the 30 second clip is just random colours in the file created
(...)
or if its even possible to do this with part of the file re encoded

Can you please explain again, personnally I haven't understood.

[reeso3000]

Ok sorry -

I have a video file with a 30 second watermark in the middle of the file so have cut it into 3 parts :-

A - prior to the 30 seconds with watermark (just cut not re-encoded)

B - 30 seconds that has been cut then delogo'd and re-encoded

c - after the 30 seconds (just cut not re-encoded)


I then append the 3 files together select "copy" under video format and Mkv as the container. The created video file plays part A fine but once it hits part B I can still hear the audio ok but the picture scrambles and is all messed up then as soon as that part ends and part C start the video comes back and continues ok. As I said when in avidemux it looks fine but the created file doesn't. As far as I can tell each part prior to appending them uses the same codecs and has the same framerate etc.

[zakk]

Ok the same thing happened to me before... I and gave up  . In fact it also happened just with parts 1 and 3 appended. Also having the same codec, size, etc... is not enough because there are plenty of parameters.

If you want to try again make sure you are cutting on I-frames, save all parts in mp4v2 first, then append in mp4v2. If this doesn't work, then you know it's not your fault