Audio is shifted during join

MrVideo

Active member
VRDpro 832f Win7

I first saw the issue in 831a.

I have two files, one is 1080p w/ AAC2.0 audio and the other is 720p w/ DD5.1 audio. I can't just mux the audio from the 720p file to the 1080p file because the black lengths are not the same. So, what I did is create elementary stream files of 6 cuts, where each cut starts at the same place. I then remove the 720p H264 files and the 1080p AAC files, renaming the 720p AC3 files to match the 1080p files, for easier joinging.

I then mux the video and audio and then add that to the joiner list.

Unfortunately the audio in the resulting joined file is shifted, except the first cut. It starts with the 2nd cut.

I've taken screen grabs of the same location in the cut and joiner files. You can see the resulting audio shift. The zip file is here: http://vidiot.com/VRD-joiner.zip

As with the other issue, the audio does not shift with version 758b for XP.
 

Danr

Administrator
Staff member
Did you do 6 remuxes and then join them? Is the shift in the joiner or the 6 remuxes?
 

MrVideo

Active member
As seen in the images, the shifting is in the join. I should have been a little more descriptive of the images. Images C1 thru C6 are the cuts, i.e., the remuxes and J1 thru J6 are the locations in the joined file.
 

MrVideo

Active member
Well, at the moment I am screwed. Taking all of the single MKV files over to XP to join them on older versions of VRD has failed. What happens in that the old version can end up immediately failing with a "ffmpeg cannot open header" error. It happened once before. I was able to remove the last mkv file (out of 6) and it worked. Then under VRDpro on Win7, I joined the joined mkv file and the last file. While I had
a little audio shift with the last segment, it was good enough. That was impossible this time around as it would fail no matter the combination.

I need this problem fixed, as I can't currently complete the project.
 

Dan203

Senior Developer
Staff member
QSF each file to a TS instead of an MKV, try the join again.

MKV is a terrible format. It only uses millisecond for timecodes, which is not high enough resolution. We try to compensate for this, but it can have issues, especially when you're joining multiple files.

If that doesn't work then you need to email us and send samples.
 

MrVideo

Active member
That begs the question: why does VRD758b work?

I was using MKV because I want the chapter marks that results when joining to MKV output. For some reason, a chapter file is not created when the output is TS, even though you know where the chapter marks are.,

There was no need to do a QSF of any of the files. The individual files I was creating were from muxing the h.264 and .ac3 files I extracted from the two main files. When I muxed the h.264 and ac3 files, I created TS files. When you join those to a TS file, there are no chapters. So, I reran the join using MKV as the output so that I could get the chapter marks, which I was going to manually create. But, I discovered that joining to a MKV file worked, i.e., no shifted audio, or at least very little as a result of having to join the audio.

Thanks for the tip, though I was expecting joining MKV files to work, since it does under VRD758b.
 

Dan203

Senior Developer
Staff member
At some point in the life cycle of v6 we switched from ffmpeg v3 to v4. I'm not exactly sure when that was so I can't say for sure if that was it or not, but it's the only thing I can think of that required a major change to the MKV code.
 
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