Can VLC handle correctly matroska v2 files?

[har-vas]

Hello all. I have noticed that VLC (0.8.6a) cannot handle correctly a matroska file when this file was created with "simple blocks" enabled (MKVtoolnix). When I select to jump on the next chapter, VLC crashes! Also, when I am trying to drag the timeline slider left or right, VLC crashes again! In few words, seeking is impossible in Matroska v2 files. Why is that? Is there any workaround? When I use Haali+TCMP everything is fine of course, so I think that the .mkv file is error-free. Thanks.

PS: There is no problem with VLC if I don't enable "use simple blocks" in mmg.

[DJ]

From the info provided this is an impossible question to answer. I can make files with Matroska that VLC won't play. I can also make files that may not play in other players and VLC will play. Matroska is a container and not a format. Also VLC is tight with Matroska and tries to stay current with the changes there.

[har-vas]

Hello DJ and thank you for your answer. Do you play normally matroska v2 files with simple blocks in your system? Can you jump and seek without any crash?

From the info provided this is an impossible question to answer.

What exactly information do you need? I am using x264 codec for video and Vorbis for audio.

I can make files with Matroska that VLC won't play.

Could you please give me an example? Do you mean with RealVideo 10 codec maybe (that's another story)?

I can also make files that may not play in other players and VLC will play.

The only example I know is a .mkv file with menues... Are there any more examples?

Matroska is a container and not a format.

I know that.

But the problem is still there: Why a matroska file is perfectly playable if I mux it without "simple blocks" and exactly the same file causes VLC to crash if I mux it with "simple blocks"? I have tried with many matroska files, not only one. Thanks.

[DJ]

1. I use mkvmerge and there is no option for simple blocks. What is the purpose? and what advantages is it supposed to offer if any? I have no problems seeking in the files I create.

2. Considering all digital video is sync to audio and that Vorbis can't do CBR it is very doubtful I would be able to cope with the jitter in any video that would be muxed using any format for the video. And yes perhaps this audio format could cause other issues for the video in seeking depending on the of encoding VBR within Vorbis.

3. If the time correction between audio and video is to great (700 ms or so as I recall) VLC refuses to play the file. But the audio and video drift in any player is enough to drive me nuts as the lip sync is never right.

4. As I recall this one has to do with mux order and how the header is written. Most players want to see Video, Audio, Subtitles and Chapters. If you have dual audio tracks keep them together and if you have multiple subs keep them together.

5. There are lots of ways to make bad files that don't play in some players and play fine in others. The trick is making good files that play properly everywhere.

BTW you can put almost any reasonable MPEG 4 video in Matroska, like XviD, DivX, H.264 and etc.

[Jean-Baptiste Kempf]

http://trac.videolan.org/vlc/changeset/19064

It will be backported in 0.8.6b tomorrow.

[har-vas]

Hello all and thank you for your answers.

@j-b: If I understood correctly, there is going to be released a new bug-fixed version. I hope this one can fix this problem.

@DJ: mkvmerge GUI has this option in the "Development hacks" (--engage use_simpleblock). In the description it says: "Enable use of SimpleBlock instead of BlockGroup when possible". Also, there is a relative checkbox in the "Settings" tab. It says that "...save a bit of overhead at the cost of not being backwards compatible". In a 90-minute 700 MB movie, I have 1 MB less with simpleblocks (699 MB). You can verify it with mkvverify by Alexander Noe.

I have no problems seeking in the files I create.

I suppose you mean in normal matroska files (v1). I have no seeking problems too. But if I mux the file with simple blocks... blabla

And yes perhaps this audio format could cause other issues for the video in seeking depending on the of encoding VBR within Vorbis.

As for the Vorbis, if I understood correctly, you are telling me that this audio format causes sync problems (or seeking problems)? Please clarify. I use almost in any case Vorbis, which I like it very much. I suppose you mean that those problems exist only in VLC.

[DJ]

At best it causes jitter, at worst is causes other errors along with seeking within a file. It depends on the level of VBR in use. There is no way to shut down VBR and make Vorbis CBR. So I don't use it with video.

[har-vas]

OK, hi there. I am waiting for the new version 0.8.6b to test my .mkv v2 files. In the meantime, I decided to create a matroska file with mp3 CBR audio (and x264 video) just to test the "simple blocks" issue. Due to DJ's comments, I was curious to know if my VBR audio streams have any connection with that. Nothing, the result was the same: Even with CBR audio, when I am trying to seek in a matroska v2 file with VLC, the player crashes!

@DJ: I found very interesting your comments about Vorbis (well, maybe because I thought that in the Open-Source community Vorbis was very well accepted), so I would like to ask few more questions. First of all, could you please explain me what is "jitter" in our case? I have not understand yet.

And now my big "complaint" from VLC, which maybe is relevant: From the first time (over two years ago) I have noticed that I couldn't seek freely inside a matroska file (even with XviD and mp3 codecs). For example, let's suppose that I am opening a movie and after 10 seconds of playback I decide to jump in the end of it. What is happening is that: the time (bottom left) continues to run normally, but the video and audio are black and silent respectively. Then, if I decide to return to the start of the movie (eg the 4th minute), the image and sound come back normally.

I have noticed that if I try smaller jumps (5-10 minutes), things are a bit better, but I have a blurred image for 3-4 seconds, dregs from the point (last frame) I was before the jump. I suppose that VLC is waiting for the next keyframe to start displaying the image clearly. Why this problem with matroska files? I have noticed that this issue is absent from the .avi files, where seeking with VLC is perfect.

So I don't use it with video.

BTW, could you please tell me what audio codec you prefer in your DVD backups? Thanks.

[har-vas]

Hello again. I just want to report that the problem with matroska v2 files is here, even with the newer 0.8.6b version. J-b, there is absolutely no improvement in that issue with the new player. I really can't understand why, given that VLC and Matroska are very close. Anyway... Now I have to play my .mkv files only in DirectShow with the help of the great Haali splitter.

Also, I would appreciate if someone could make any useful comments for the serious issue I mentioned in my previous post. Thanks.

[Jean-Baptiste Kempf]

What about the development version ?

[DJ]

Any format that can do CBR will work better. MP3, ac3, AAC, DTS are all capable of CBR.

Jitter is not playing frames at the proper time but is not skipping frames. This is generally a sync issue caused by an audio card.

[har-vas]

@j-b: If you mean the nightlies builds, I have already tried them! Things are even worse, because I can't even start the player! After the installation, I am trying to run VLC 0.9 and the player crashes. I have tried many times in TWO machines. I always make a clean installation after previous unistallation. So, I just hope and wait for the final release. To tell the truth, I suspect that the developers don't work on that field, because few people making matroska v2 files at this time.

@DJ: Yes, I do understand that when we have CBR streams the seeking is by far easier and faster, but I consider CBR audio a waste of bitrate. I am always working with ABR (in general VBR) audio, Vorbis or (F)AAC. And I select the matroska container exactly because I know that is better on handling such streams and provides fast seeking and great sync. I think that the splitter is the critical thing in the subject we discuss, not the type of streams. In DirectShow (Haali) I have great seeking, but that's not enough (eg Linux case), that's why I insist on VLC.

[DJ]

Then you will always have jitter (even with Haali) in any player.

[ssbssa]

@har-vas: i tried it out with --engage use_simpleblock, and you are right, it crashes with 0.8.6b.
however, it works on the nightlies (the one i used is a week old or so).

[har-vas]

OK, I just want to verify that the upcoming version 0.9 seems to resolve the issue with matroska v2 files! Ssbssa, you are right, I managed to install and run a nightly build (27/05) and I saw that it can seek normally in a modern .mkv file. This is very positive!

Although, the well known problem with the large seeking in matroska persists. When I open a .mkv movie, I can't get immediately and directly to the end of it, exactly as I described in a previous post (please read). I can go forward until a particular point only, while this does not happen eg in .avi case.

I think that it is a must for a modern player to provide free seeking in every video file.

[anotherclick]

Same thing here, i can't seek. I don't know why, because the program plays the subtitles and the timer is still counting like you said. I tried to disable the video track and then re-enable while playing, and bang, it's working, but it's not good like this.. i wanna seek.

The Funniest thing is, it worked till i changed some language settings in xp.. i tried to reinstall vlc with every preferences deleted, but it didn't help.