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View Full Version : Mkvmerge "micro-stutter" issue


KennyXL
28th January 2008, 22:34
Hi,

Long time lurker, first time poster. I'm sorry if this issue has been covered before, but I have tried for days to find the answer to my issue by going through this forum and other sites. If my issue has been covered, please just give me a link to the proper thread because, believe me, I've tried looking for it exhaustively. Here it goes:

I use Evodemux to get files that I can use in Megui to create an h.264/.mp4 file. From there I use Mkvmerge to combine the .mp4 and .ac3 file into a .mkv which can be played on my home theater PC. Both the .mp4 and .ac3 play smoothly on their own (albeit with no sound or video, respectively). However, the resultant .mkv file has what I believe others have referred to as micro-stutters. It's like it's sticks for a fraction of a second before jumping to the proper frame causing a slight, but noticeable jittery effect. It doesn't speed up because it is synchronous with the sound (which plays smoothly) it just kind of jumps. I've done this with at least 4 files. In every case, both the .mp4 (from Megui) and the .ac3 (from eac3to) play fine on their own. It's only when they're combined in Mkvmerge that these stutters are introduced. I've looked into the timecode, but there doesn't seem to be any site or link that tells you how to create a timecode file and the option is disabled in Mkvmerge anyway. I can't believe I'm the only one with this issue since it seems a lot of people use Mkvmerge, but nobody has really brought it up. I'd be willing to use another tool, but I can't find another one that doesn't involve re-encoding the files (which I already have and were very time-consuming to create). Any suggestions or links that might help me? Anything would be appreciated. Thank you for your time.

rickardk
29th January 2008, 13:04
I have the same experience with some titles... Don't know why nobody else don't notice this

[)370|\|470!2
29th January 2008, 16:52
No clue what causes this, but in my experience after reencoding the audio stream, problem ceases to exist. :D

KennyXL
29th January 2008, 18:23
No clue what causes this, but in my experience after reencoding the audio stream, problem ceases to exist. :D

Hi,

Thanks for the reply. Can you tell me how you go about doing this? The finished product is a .mkv file with h.264 and .aac/.ac3 content. What procedure do you use to re-encode and reintegrate the audio stream? Does this involve transcoding the video as well? Please give me an idea of which application you use on the .mkv file and the order in which it is done. Thank you. Bye!

Adub
29th January 2008, 19:25
Demux with MKVextract.

Re-encode the audio with your favorite AAC encoder, ex. Nero AAC.
You can also use a GUI to do this for you, such as BeHapppy, BeLight, MeGUI, etc.

Remux with MKVmerge.

KennyXL
29th January 2008, 21:11
Demux with MKVextract.

Re-encode the audio with your favorite AAC encoder, ex. Nero AAC.
You can also use a GUI to do this for you, such as BeHapppy, BeLight, MeGUI, etc.

Remux with MKVmerge.
Hi Merlin7777,

Thanks, I'll give that a try tonight. I'm not sure why that would solve the issue since I've tried muxing with mkvmerge with an .aac stream as the audio previously, but if you think it's worth a try, I'll give it a go. Does the process of "un-muxing" a .mkv file change the video in some way as to prevent the stuttering that you're aware of? Or is it the un-muxed, recoding of the .ac3 file to .aac the thing that fixes it? Or is is it just one of those things where nobody knows why it works...it just does? I'm just trying to learn like everyone else. Bye!

Breakthrough
31st January 2008, 01:45
Have you tried muxing them into a transport stream container instead?

http://forum.doom9.org/showthread.php?t=134104

That should do the trick. Depending on what you've installed on the PC, either the TS and/or M2TS files that the program can generate will be playable on the target PC.

KennyXL
31st January 2008, 19:03
Have you tried muxing them into a transport stream container instead?

http://forum.doom9.org/showthread.php?t=134104

That should do the trick. Depending on what you've installed on the PC, either the TS and/or M2TS files that the program can generate will be playable on the target PC.

Thanks for the suggestion. I wanted to keep it in either an .mp4 or .mkv container since those seem to be the most popular. Oddly enough, I decided to go with .mp4 shortly after I posted the thread and have not had the same issue I had when I used Mkvmerge. Transport Stream or looking into some of the newer .avi profiles was going to be my next step...you know, working my way down the ladder. Bye!