I decided to give Matroska a try as a media container (before, I've been using OGM) and to me, it seems as easy as selecting mkv in VirtualDubMod. I downloaded the matroska pack as well so a few questions came to mind.

1. I have Tobias' OggDS installed so is it recommended I use CoreVorbis? I do have some OGM stuff lying around so I'd like to keep OggDS. But is CoreVorbis any better in any regard?

2. Is the Matroska format finalised? That is, will the mkv files that I make today be fully compatible with future releases? As with most open source stuff, new features are added by the day and things evolve over time. With OGM, we sort of have the notion that the Ogg file format was finalised and nothing majorly significant was gonna be introduced which will break the OGMs I made today or any new feature that I'm currently missing out. If there are still things to 'fixed' or 'added' to Matroska, then I'd probably wait until they're finalised so I know I'm not missing out on anything

3. I know there's been a lot of discussion and debate about the Matroska versus OGM. Can someone give me a fair overview of why its a good idea to consider using the former over the latter? A brief comparison of technical merits between the two would be good

Thanks for your time.

EDIT: For my purposes, I use DivX 5 for video and Vorbis for audio.

CoreVorbis is definitely necessary to play Vorbis audio from matroska. OggDS will result in stuttering audio and/or video if its decoder filter is used in combination with matroskasplitter.

However, there is no need to deinstall OggDS if you install CoreVorbis, as both can peacefully coexist on your PC without problems, as they are using completely different MEDIATYPES when connecting in a DirectShow graph, so there is NO interference between the both. Also, CoreVorbis doesnt come with an Ogg splitter filter, so it cant replace OggDS at all. For this reason

- old OggDS slitters from Tobias can not connect to CoreVorbis for Vorbis decoding, they will always use their own Vorbis decoder
- matroskasplitter will first search for CoreVorbis for Vorbis decoding, only if it isnt present it will connect to the OggDS Vorbis decoder as a fallback system
- new versions of OggDS ( like 0.9.9.6 ) from Nic will also first try to connect to CoreVorbis, as he added the new MEDIATYPES in these version, and then use its own decoder, mainly because CoreVorbis has some nice advantages



Nope, matroska is definitely NOT finalized. The container is still worked on heavily, new things are added over time, etc. Now, the important part of your question was, '..will my files play in future...' , and here i can give a very clear 'yes' !

The nice thing about EBML, the underlying framework of matroska ( mplayer and FFMPEG people would call it 'bloated' ), is that it allows to easily add new elements to the file to add new functionalities, without making old elements obsolete. A very good example of this is the new lacing sheme we added recently. The old lacing sheme is still valid and a part of the specs, so old files are still 100% spec compliant, but we extended the system to make files with lower overhead possible.

To give you a good feeling here, i have some files that i created with a pre-release version of VirtualdubMod beginning of this year, using an early alpha libmatroska, and they still play fine with latest matroskasplitter from gabest, who was rewriting libmatroska completely, using just the specs and nothing else ...

... i wont, for obvious reasons ....

Subtitles seem to work better in mkv... i had some trouble putting 11 subs in an ogm, but i worked perfectly in an mkv. That's the only reason for me to use mkv so far.

Couple of things that came to my mind on this thread...

1- When I first tried the Matroska pack, it failed to register de DS parser... Maybe it was just my system, or maybe it was a known problem. It was months ago... Does anybody know something about this?

I solved the problem recently by registering the .dll file manually, and now it seems that .mkv files play nicely in my computer, but I would like to get the confirmation of a nice, simple solution for a standalone executable to include in the CDs of my rips... Tips welcome

2- Newer versions of the OggDS filters from Nic???? Where?!?!!?

Look at http://forum.doom9.org/showthread.php?s=&t....6&pagenumber=1

or direct download
without instaler
http://nic.dnsalias.com/OggDS0996_bin.zip
with instaler
http://nic.dnsalias.com/OggDS0996_inst.zip

For matroska installers, go here : http://packs.matroska.org

I've got another question regarding using Vorbis file in mkv. I have an ogm video file which has vorbis audio with postgain (I ran Vorbisgain before muxing the vorbis file). Now, when I convert this ogm to mkv using VirtualDubMod, I lose the postgain (CoreVorbis reports postgain of 0 dB). I've tried demuxing the vorbis file, vorbisgaining it, and muxing it back in to the mkv, but CoreVorbis still comes up 0 dB postgain. I dont have this problem with OGM though.

Any thoughts?

Try the latest version of CoreVorbis which finally reads the REPLAYGAIN_TRACK_GAIN tag.
Hmmm! that make me think I've probably forgotten to disable the code for OggDS handling.
So this version will probably connect to OggDS, but it's not ready yet, seeking is b0rked.

Thanks for the reply. I installed the latest Matroska pack which I assumed has the latest CoreVorbis stuff and the Postgain works now!! So now I get exactly the same functionality as OGM which means I can migrate to mkv now.

btw. I create my mkv's using VirtualDubMod. Do I have to update the Matroska support in VirtualDubMod whenever there is a bugfix or newer version of the format?

No, only if we implement a major change into the format like the new lacing system. Even then, all existing files are still 100% spec compliant and dont need to be changed, its just that you maybe cant process matroska files coming fom other people, using a newer version of the lib ....