Splitting mkv files

[carlmart]

MKVmerge is my program of choice to merge mkv files, and I must say it's quite effective.

The only lacking area is split. It's quite inaccurate and doesn't "obey" size or time commands for setting splitting points.

Is there anything I can do to improve on that? Is there any other program that might do that better?

[hech54]

MKVmerge is my program of choice to merge mkv files, and I must say it's quite effective.

The only lacking area is split. It's quite inaccurate and doesn't "obey" size or time commands for setting splitting points.

Is there anything I can do to improve on that? Is there any other program that might do that better?

It depends on what type of video is inside the MKV "container".

[carlmart]

AFAIK it's H264 1080p video.

I have already read here and elsewhere that it's not possible too much accuracy using MKVmerge, and that it can't be less than 250 frames. In my case we are talking around 100 frames, so maybe this not the way to achieve that.

[jagabo]

The GOP size varies depending on the encoder settings and on the content. x264 for example has settings for minimum and maximum GOP size (defaults are 25 and 250 but they can be set to any values you want). The default is to start a new GOP at each scene change (but not less than the minimum GOP size). So the GOP size is unpredictable.

[carlmart]

Right.

There's a program called SolveigMM that was mentioned on another Videohelp thread that seems to do a better trimming job. I'm already trying it, but it stopped processing at 98% and froze there.

Does anyone know this program or can say what might be happening?

[poisondeathray]

IMO, it's probably one of the "Better" smart editors for h264/mkv at this point. Sometimes some streams still cause problems, there might be errors in the stream, or some encoding settings cause problems. You can send sample stream to them and they will "fix" the problem if it's "fixable" - this way the program can improve. As an alternative you can try videoredo , there is a free trial.

[carlmart]

It's interesting: trimming with both programs, MKVMerge and Solveig, cuts at exactly the same frame. Which unfortunately it's before or after the point I wanted.

So there seems to be "something" on the video stream that "sets the net". What that might be?

[poisondeathray]

in solveig you need to explicitly enable frame accuracy , otherwise it cuts on GOP boundaries like mkvmerge or avidemux

control=>frame accuracy (smart mode)

[carlmart]

Well, things got trickier.

The whole problem is this: I'm swapping the audio track, from one video version to another one. That is I have a high bitrate version with AC3 2 channel audio, and a lower bitrate version with AC3 5.1 audio. So I'm putting the AC3 5.1 audio in the higher bitrate version.

That works fine and syncs perfectly after adjusting in MKVmerge, except the audio starts later on the 5.1 version, leaving mute the beginning in the new merged version.

So what I need to do is trim the whole video & audio after track replacement.

Trimming was not working perfectly with MKVmerge due to GOP boundaries, so I tried Solveig.

The problem with Solveig is that I can't make it do the trimming on the new merged versions.

So I wonder if I shouldn't start in a different way: do the trimming first on high bitrate version with Solveig, and replace/resync the audio later with MKVmerge.

[poisondeathray]

Try it out. It might work, it might not . There is no way of knowing until you try some things out

So you're basically implying that the lengths are different, or at least the 2Ch version has a longer intro section

Another way might be to make a fake 2.0 => 5.1 (even with blank channels) intro section, then append that beginning section to the original 5.1 audio track

[carlmart]

Yes, the 2Ch version has a longer intro, which is unnecessary.

But just now I picked a malfunction in Subtitle Workshop, which is my subtitle editing program of choice, and I had lost video/audio playing with it.

As the only program I had installed was Solveig, I suspect it might be messing with the Matroska or other codec install, which I can't allow. Let's hope not.

A similar problem made me re-install Windows 7 recently, as I couldn't cure it. Now I have blocked out all MS updates, as I think that had been the problem on that case.

To solve my problem now I reinstalled Matroska, ffdshow and directvobsub, and got my audio & video back.

This subtitle program is very tricky, but I couldn't yet find a better one.

[carlmart]

Things turned out perfect. A bit tricky to trim and fix the cutting point, but it worked out in the end.

After trimming with no audio in Solveig, I added and synced the audio in MKVmerge.

Thanks for the help.

[skaleton]

Thank you calmart for asking the question, which I was asking myself too, and jagabo and poisondeathray for their informative replies.

[edit]

in solveig you need to explicitly enable frame accuracy , otherwise it cuts on GOP boundaries like mkvmerge or avidemux

control=>frame accuracy (smart mode)

Are you referring to the trialware version, because I can't see any control option in the freeware SolveigMM AVI Trimmer + MKV?