I have a .mkv (Matroshka) file to import into Vegas Pro 17. I have demuxed the file with VideoLAN, to create an MP4 file with video. The converted file plays on my desktop, but when imported into Vegas, all I have get is the audio, and no video. What steps am I missing? Or is there a better way to convert this .mkv file?
Please post media info on your mp4 file https://www.vegascreativesoftware.info/us/forum/faq-how-to-post-mediainfo-and-vegas-pro-file-properties--104561/
Handbrake is often recommended for converting to mp4 files that Vegas has no problems with.
if you try that mediainfo and it says the video codec is vp9 or something unusual like AV1 then vegas can't read it. You have to transcode to AVC instead with something like Handbrake
Rather than transcode, you could try the ImportAssist tool in Happy Otter Scripts which can rewrap and convert VFR to CFR. If all else fails, there are options for transcoding, although not recommended since you lose some quality unless converting to lossless. You can also import subtitles and chapters if desired. Here's a very simple example.
More information can be found at https://tools4vegas.com/
Rather than transcode, you could try the ImportAssist tool in Happy Otter Scripts which can rewrap and convert VFR to CFR.
Hm. I thought this is not possible with simple re-wrapping. What am I missing?
It's more than just rewrapping. For MKV files, the conversion from VFR to CFR is also important. Apparently, the MKV container writes time stamps "differently" so that most files show up in MediaInfo as VFR (even though the original file was CFR). Running it through the VFR to CFR tool seems to result in the correct time stamps so that it is now considered CFR which is important to Vegas.
In any case, it does "work" with the option for extracting multiple audio streams, subtitles and chapters. Importing AC3 files as VOBs is a little "trick" since Vegas does not natively import AC3.