.h264 MKV files to something compatible with Vegas?

Anyone have any ideas on how to do this and not have a massive quality loss? I've tried about 6 different programs and none of them have either worked or worked well. I need to be able to edit these videos in Vegas 10. Thank you!

convert to lossless AVI (lagarith codec). You will need to write a one-line directshow anvisynth script to open the MKV in virtualdub, then save as AVI. You'll be able to edit perfectly in Vegas then with no quality loss. The avisynth script would look like this:

Thank you!!! I'm not great with this stuff, but I think I know what all that means. Let me give it a shot.

Its pretty easy. Here are the general steps:

-first you need to have the lagarith codec installed, and virtualdub
-Open up notepad or some general text editor
-copy that script I pasted above, and modify it to your file and location, and framerate
-save as All Files with .avs extension (ex: MKVscript.avs)
-open this *.avs file in virtualdub.
-under video settings change compression to lagarith (under settings, it should be set to RGB as default, Vegas requires RGB)
- set your audio (I generally set it to NO AUDIO and handle this separately)
- FILE -> SAVE AS AVI...

for audio, I generally demux the audio stream from the MKV (using MKVextract, in the MKVtoolnix package) and split into 6 mono WAVs using BeSweet. If you just want a PCM stereo track or something, you can have virtualdub convert it to this and include in your AVI (change audio settings to full processing mode, and change the compression).

hope that helps

also, just a heads up, but lagarith AVIs don't carry anamorphic flags. So if by chance your video is something like NTSC anamorphic widescreen (stored as 720x480, but stretches to 853x480 upon playback) you need to tell Vegas that your clip has a PAR other than 1:1. You can do this by right clicking on the video in the Vegas timeline, and changing the media properties.

I doubt you will have this problem going from MKV though, most of them have a square pixel aspect ratio (1:1 - i.e., no anamorphing). Just want to give you a heads up, in case your AVI looks stretched one way or the other, and you didn't change the dimensions - It's OK, you just have to tell Vegas.

Thanks so much, this all works beautifully.