encoded file is slightly out of sync

[pooksahib]

Hi. I have an mkv file here with a very high bitrate so I want to encode the video but keep the original audio. Using Megui, I've indexed with both Smash and FFMS but both times I've ended up with a slightly out of sync file (I muxed the new video with the audio file extracted during Indexing).

The original mkv has perfect sync so can anyone suggest why the encodes do not?

(I thought I'd try Direct ShowSource as an Indexer but got the error "this pin cannot use the supplied media type". Maybe that's a clue to the problem?)

My thanks for any help or suggestions offered.

[johns0]

Trying encoding with vidcoder and see if you get the same result,if you do there might be a glitch in the audio where your player bypasses the glitch but encoding corrects the error causing sync loss.

[jagabo]

Out of sync in what way? Maybe you just need to set an audio delay when you mux.

[pooksahib]

Although the original mkv had perfect A/V sync, my recoded video muxed with the original AC3 audio had an A/V sync difference of 0.1 sec. I've done a further encode, this time recoding both video and audio and the result is fine. Ideally, I'd have preferred to keep the original audio but it's not a problem if I can't. But when when weird things like this happen, I just like to know 'why?...'

Regards to you both.

[jagabo]

The audio and video in an A/V file don't have to start at the same time, don't have to end at the same time, and don't have to have the same duration. It sounds like your source audio had a 0.1 sec delay (or advance?) but you didn't apply that same delay when you remuxed. When you reencoded both the audio and video the software compensated for the delay before encoding.

[johns0]

Run the mkv through mkvmerge and apply a delay in the audio.