Force FourCC In Matroska

[chepe36]

I searched a lot and couldnt find any topic that said anything about this, also i tought this should be here since it talks about matroska but feel free to move it.

is there any way to Force FourCC in matroska?(like in virtual dub for avis)
i need this because
1: i have a file that is in native matroska (it doesnt have an avi inside so it doesnt has FourCC)

2: i have a file that i transmuxed from wmv to mkv but it has WMV2 FourCC and the codec that has vfw intrface has WMV3 FourCC so i need to change it to WMV3 to be able to use it.

[ChristianHJW]

Originally posted by chepe36 1: i have a file that is in native matroska (it doesnt have an avi inside so it doesnt has FourCC)

Sorry, but thats almost impossible, as there is no app released that could create native video files yet. The first tool ever to do that is DaveEL's avs2matroska, and this is not released yet. Now, if you had a native file you couldnt watch it still, as we have to release the parser filter supporting this first.
You care telling us what file it is, what native video format was used and where you got it from ? You ran mkvinfo on the file ? What video ( matroska codec ID ) type does it report ?

2: i have a file that i transmuxed from wmv to mkv but it has WMV2 FourCC and the codec that has vfw intrface has WMV3 FourCC so i need to change it to WMV3 to be able to use it.

I guess you were using Gabest' muxer filter on DShow to transmux it ? We dont have a tool yet to change that in the existing file, but of course its well possible. Maybe jcsston's shell extension could do it one day, or Mosu adds a switch to mkvmerge to force a certain FourCC type when reopening the files .... the easiest way would probably be VirtualdubMod, if Cyrius would make the 'open with FourCC' function available for mkv files ...

[ChristianHJW]

Originally posted by chepe36 (it doesnt have an avi inside so it doesnt has FourCC)

Just to clarify this : In the 'AVI/FourCC compatibility mode' we dont put the complete AVI inside the MKV file, that would be completely stupid. We only copy the BITMAPINFOHEADER, including the codec's FourCC and all the VIDEOINFOHEADER structs ( if available ) into the 'Codec Private Data' field of matroska, and set the matroska codec ID to 'V_MS/VFW/FOURCC', to indicate that this is an AVI compatibility file. This was introduced to ensure that EVERY VfW codec can be supported, and EVERY AVI file can be transmuxed into MKV .... all codec IDs can be found here (http://matroska.free.fr/specs/codex.html)

[Atamido]

Originally posted by chepe36
2: i have a file that i transmuxed from wmv to mkv but it has WMV2 FourCC and the codec that has vfw intrface has WMV3 FourCC so i need to change it to WMV3 to be able to use it. First, how did you transmux a file from WMV to MKV?

If you want to change the FOURCC stored in Matroska for the vfw compatability mode, you should be able to use a HEX editor to search for "WMV2" and just change the 2 to a 3.

[chepe36]

@ChristianHJW

ok the native matroska file that i used was DaveEL's mpeg4 file that i downloaded from the matroska website ;)

and thanks for all the info its really interesting jeje

@Pamel

Great idea i'll try that and see if it works, i guess sometimes the more simple ideas tend to be the most usefull

[ChristianHJW]

Originally posted by chepe36 @ChristianHJW : ok the native matroska file that i used was DaveEL's mpeg4 file that i downloaded from the matroska website ;)

:eek: :eek: :eek: .. this is unreleased stuff, and highly confidential :confused: ...... :D !!

[DaveEL]

Well if people want to grab stuff from the broken directory on my site they deserve everything they get. In fact i believe if you get the latest sample and the current release filter it will almost play well some of the frames will play anyway. :) Hopefully the decoders will be sorted soon either that or perhaps the matroska splitter will be changed to give the kind of timestamps that the current decoders expect instead of the correct ones.

DaveEL

[Kurosu]

Originally posted by Pamel
If you want to change the FOURCC stored in Matroska for the vfw compatability mode, you should be able to use a HEX editor to search for "WMV2" and just change the 2 to a 3.

Isn't there a CRC-check or the like that will prevent this? I tried this once with OGM files, without success. But matroska files aren't ogm files :)

[robUx4]

No, there's no CRC check for the moment.
It will be added later. (hopefully there will be tools to change the FourCC by that time)

[chepe36]

Originally posted by ChristianHJW
:eek: :eek: :eek: .. this is unreleased stuff, and highly confidential :confused: ...... :D !!

are you serious???

sorry I didnt knew...

[DaveEL]

:)

my clips are not confidential but are marked as broken but anyway im in a good mood so i thought i would give a quick status update on mpeg-4 iso playback... IT WORKS!!!!

My fix is a little kludgy currently and you have to construct the filter graph by hand in graphedit but it does work. so with any luck expect the files to play with the next release.

DaveEL

[bond]

great to hear that!

[chepe36]

wath are you talking about your files play perfectly when i open them in my pc (i dont have to make the graph, i just open it in mpc)

using the official matroska filter and no ffdshow

[DaveEL]

Your not using my sample then. What video are you talking about.

DaveEL