[jwoolen]

I've been playing with Dharma since the betas came out, and I noticed that there is video stutter on certain *.mkv files I play that wasn't present with Camelot. In an attempt to find the cause of the stutter, I remuxed the file with only the video track and the stutter went away. When I remuxed the file including the original audio file (a 1509kbps DTS track) the stutter returned. I'm wondering is this condition unique to my setup or has anyone else experienced this.

I've encountered this problem on three XBMC machines:

1. An Acer Aspire Revo 3610 (Atom 330, Nvidia ION)
2. A Lenovo IdeaCentre Q150 (Atom 510, NG Nvidia ION)
3. A Jetway Mini Top (Atom 525, NG Nvidia ION)

When the stuttering occurs, no frame drops occur, vq and pc remain stable, and CPU load on each core is under 10%. This doesn't occur on every file, and I think it could possibly be related to the header compression option in newer builds of mkvmerge. I used 4.0.0 to remux the file, but it was originally muxed with 4.2.0. If anyone can share their experience, I'd greatly appreciate it.

[bossanova808]

There are stacks of other messages about stuttering - you're definitely not alone.

Stuttering with ION seems to be the norm. It's not extreme - many people I htink don't even notice, but if you're sensitive to it you can see it's pervasive through XBMC and it seems no amount of tweaking will get rid of it - it's definietly the audio syncing that does it - you can watch the error - it stays at 0% or verry close to but with every little judder there is a flash to 100% for a moment. As you say, no frame drops.

Something isn't quite right....it's not the header compression, it's been around for a while - I upgraded from Camelot to SVN some months back in an effort to solve it. I have a perfect xorg.conf (according to the stickied script) etc, and have tried all the syncing options and remuxing I can think of to no avail. AS you say - some files are ok, others are not - namely Avatar and Up either played or remexed from Bluray, for example.

I never did try pulling out the audio - seems obvious, and I am not at all surprised the stuttering disappeared...

[bossanova808]

Actually I notice in trac there has been work on 'timstamping' related fixes which may by related....I am a little frustrated as most likely this won't be in Dharma so I will probably have to venture into SVN territory again to try it out and I would really just love a stable, basic install with smooth video at 23.97 in particualr....

[bobo1on1]

Please post a debug log.

[bossanova808]

Unfortunately I am so far back with my post camelot SVN I don't think it's useful but hopefully the OP will. I won't upgrade until Dharma stable I think, as I fear the wrath of my wife if I break our system!! I am getting a new system next week (Shuttle xs35gt) so I will have two systems to play with then.

And sorry reading that back up above I sounded snarky - it's just frustration because I've been trying things to solve it for quite some time, but I should point out's it's only minor stuttering in the big scheme of things - and XBMC is a totally awesome piece of software that is a testament to the amazing abilities of the people who wrote it. I'm feeling so guilty I just donated.

[jwoolen]

Even though mkv header compression has been around for a while, it wasn't enabled by default in mkvmerge until 4.1.0. I ran into issues with this with my WDTV Live Plus not playing the DTS audio on files muxed with header compression. Remuxing the file with a version of mkvmerge prior to 4.1.0, in my case 3.4.0, fixed that issue on the WDTV. However, playing the resulting file in XBMC (Dharma) causes video stuttering (audio plays without stutter). So, I reloaded the original file muxed with 4.1.1, and the stuttering stopped.

The following actions also eliminated the stuttering:

1. Remuxing with no audio track.
2. Remuxing with an AC3 audio track.
3. Remuxing with a different DTS track.

Just thought I'd share my findings for anyone with a similar problem without access to the original file, or for anyone who owns an XBMC machine and a WDTV Live.

[rav994]

actually demuxing the audio with mkvextract, and remuxing the same audio file will also work.

[bossanova808]

Hmm - can you post a debug log of the file that plays with stutter on XBMC - might help the devs get to the heart of the issue.

I'd kind of assumed that plenty of my recent mkvs would have this issue as people would be muxing with the latest mkvmerge, and I haven't seen any increase in stuttering of late, just the same level.

[jwoolen]

actually demuxing the audio with mkvextract, and remuxing the same audio file will also work.

I wish I'd tried that sooner. I wouldn't have had this problem if I would have tried that in the beginning.

[SteveGoff]

I'm having bad stuttering with SD MKV files, but not with HD files. They were all made with MakeMKV, and none of them stutter using other programs. All of the sd files have AC3 audio. My PC has an i3-530 and an ATI HD 5450.

EDIT: Sorry, posted in the wrong thread, since I run windows 7.

[jwoolen]

I've been playing with Dharma some more and I've found that mkvs with flac (2 channel and 6 channel) audio have a lot of jerking, sometimes pausing for a few frames. Replacing the flac audio with either ac3 or dts, or removing the audio alltogether stops the jerking. I've been running openelec, and I don't know how to get a debug log. I've encountered the same issue using the official dharma beta 2 image. Anyone have any ideas?

[loot87]

I'm having the same issue with VOBs on all of the Dharma betas from XBMC and from XBMC Freak. I use a Zotac Mag. This only happens with my VOBs, not with my m2ts blue ray rips.

When I revert back to 9.11, the problem goes away.

[theuni]

Could one of you please post a sample somewhere so that we may reproduce the issue?

TheUni

[loot87]

I'll work on getting a log tonight.

[loot87]

Debug log is here:
http://pastebin.com/sCpZnKp4

XBMCfreak-1000-beta3
Default playback settings. Movie located on SMB share.