Segment Boundaries and audio sync.

MKV playback, recompression, remuxing, codec packs, players, howtos, etc.
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Samuel033
Posts: 2
Joined: Thu Feb 04, 2016 11:24 pm

Segment Boundaries and audio sync.

Post by Samuel033 »

A new guy here. And also new to backing up blurays. DVDs never a problem tho.

The few I have done so far seem to be fine except for one. A concert video. There are two parts to the concert. The main and an encore. On normal playback it functions as one. Chapters 1-24 and 25-32. The video itself is broken into 2 m2ts files which represents the two parts.

The problem is audio sync when it goes from the main to the encore. 26 seconds worth of silence. Yup 26 seconds. Been working with both this program and also dvdfab for non-compressed mkv rips. Same problem for both but different results. MakeMKV has silence for that 26 then the cut off but synced audio plays. The log says those duplicate frames are all dropped, which I assume is the way its supposed to work. The other doesnt drop anything but with the obvious result of the audio being extremely late.

To get a reasonable result I ended up doing partial rips. The main and then the encore. So two mkv files. This is not a big deal in the grand scheme of things in this case since its a natural fade-to-black cut. I am sure I can merge the two of them together. Or I might delete that amount of time of silence in the audio tracks (the num of deleted frames = the number of dropped frames via the makemkv log).

But I am wondering if there is some setting somewhere that deals with situations like these manually or automatically. Or if this is just an oddball disc that must be fixed by hand with merged files or something like that. Its brand new and not scratched.

Thx.

edit: I just saw another thread that suggested that kind of issue could be an audio stream that is longer than the video for the first part.

edit again: Just for reference, this is the log line

AV sync issue in stream 1 at 1:55:38.922 with duration of 26.016s : 813 overlapping frame(s) dropped at segment boundary
Samuel033
Posts: 2
Joined: Thu Feb 04, 2016 11:24 pm

Re: Segment Boundaries and audio sync.

Post by Samuel033 »

Well what I ended up doing is using the log info for dropped frames at that moment and editing the demuxed audio file to remove those number of frames of silence at the specific point. Only needed the PCM track so recompressed it into ac3 or aac. One of those. Then added it back with the video. Seems to sync up with no problems. Just fortunate it was as the scene boundary not in the middle of anything. I will next try editing the existing ac3 stream itself without the need to recompress it.
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