Why the Need for Matroska & ffdshow to Play XviD's

[Hammerdown]

So I'm having really good success encoding HDTV with XviD (avisynth & VdubMod)! I decided to put some clips on a DvD an try to play them on my Laptop. After I installed the XviD codec pack on the laptop, the files showed up as the wrong length, the audio plays but the video is just black (no video).

I found GSpot that examines the AVI for header info. GSpot reports that all my XviD encoded clips are "Invalid AVI Files", and a bunch of n/a's in the video & audio codec info. There is a "Render" function that finds the codecs that are on the machine that can playback the file. Here is what it finds:
Video - matroska splitter->ffdfshow MPEG4 decoder
Audio - matroka splitter->ac3 filter

After seeing this and comparing the ZP settings of my htpc with my laptop, I got the clips to play by installing matroska and ffdshow.

When I used to encode with DivX, I never needed any other filters installed to play the avi. So why won't the XviD's play by simply installing the XviD codec? Why the need for Matroska & ffdshow? Most importantly, is there some steps in the encoding process that mess up the header info?

Remember I'm new to this encoding stuff.
Hammer

[stephanV]

:)

you probably saved as matroska file in VirtualDubMod, make sure you select "save as avi". If you want your old files to be avis again then open them in VDubMod select direct stream copy for video and audio and then save as avi.

Matroska is a different container format (audio/video-"wrapper" from AVI so your header is not corrupted: there just isnt an AVI-header to begin with.

[Hammerdown]

Ya your right, I did save as mkv when encoding then simply renamed to avi (I was following an online guide). I will try save as avi on my next project. I'm also using mkvmerge GUI to add AC3 after encoding the video. So I assume I must save as avi there too.

I tried re-opening my finished XviD avi's in VdubMod and it crashes the program with no error messages. It just shuts it down after the "preparing makroska file" import dialog box is done. Is that some known issue?

Hammer

[stephanV]

Originally posted by Hammerdown
Ya your right, I did save as mkv when encoding then simply renamed to avi (I was following an online guide).
Dump that guide, it sucks. Maybe you could post the link here?

I will try save as avi on my next project. I'm also using mkvmerge GUI to add AC3 after encoding the video. So I assume I must save as avi there too.

what kind of files do you want? AVIs or Matroska? if you want avis use AVIMux GUI


I tried re-opening my finished XviD avi's in VdubMod and it crashes the program with no error messages. It just shuts it down after the "preparing makroska file" import dialog box is done. Is that some known issue?
dunno, maybe the link to guide will clear up the issue...

[Hammerdown]

"The HDTV TO XVID Walkthrough"
http://www.chade.org/HDTV/index.htm
BTW it does say on the VIEWING page of the guide that matroska is needed for playback.

Thanks I will try AVIMux gui next time too!

Hammer

[stephanV]

aha, so you hadnt read the guide carefully :p (and it didnt tell you to rename the file either ;) )

in any case Matroska is not really required for XviD with AC3-sound, you could just as well do it in AVI. It's your choice, either way is good.