I should not have said common, but statistically in 2019, the largest percentage of mkv files in the world today would be produced by YouTube and those use VP9. Every video from 144p to 8k exists a vp9 mkv file. 1440P videos and above you only have the vp9 option either in mkv or webm. I would never use a re-encoded file created by a YT downloader. I would only trust myself with creating a lossless transcode.

I should not have said common, but statistically in 2019, the largest percentage of mkv files in the world today would be produced by YouTube and those use VP9. Every video from 144p to 8k exists a vp9 mkv file. 1440P videos and above you only have the vp9 option either in mkv or webm. I would never use a re-encoded file created by a YT downloader. I would only trust myself with creating a lossless transcode.

Khm...there's a way around it.

 Every video from 144p to 8k exists a vp9 mkv file. 

I'm not seeing it. Would love to see your basis and documentation for that notion.

The most common available MKV files would be 4k video from youtube

I must disagree entirely on historical premise.

VP9 is a relatively new streaming codec (four years maybe?), and only a few download utilities grab the actual MKV file from YT -- most just convert it to AVC on the fly.

The vast majority of MKV encodes, and there are millions and millions out there, is storing and delivering DVD and BluRay rips, legitimate or otherwise. It's been around fully fifteen years, at least I've used it for a decade for my own titles. Unfortunately, it's become the preferred medium for pirates and torrent sites, as DivX once was in past decades.

MP3 audio was the original preferred medium for pirates as well. It's likely one of the reasons it is currently the preferred lossy audio format with the most support today. So I would not condemn MKV for that reason. I would actually prefer if it had more support due to that reason.

One of the reasons I really like the MKV container file format is because it seems to be the closest thing I've found to BluRay where it supports multiple language/audio tracks as well as multiple subtitle selections where those different audio and subtitle options can be selected and played back on my Samsung HD TVs. For me, that sounds like it would be a wonderful thing to be able render multiple audio mix tracks from within Vegas to a single container file format.

I'm unsure of the limitations of MP4. I just know I've never found the ability to select multiple audio mixes within a single container other file format other than MKV. Does MP4 have that capability or is there any other container file formats that do and is its playback widely supported by TV's such as Samsung and LG? Hard to make a case against better support of MKV when the format is supported by two of the largest/leading TV manufacturers on the planet.

"The most common available MKV files would be 4k video from youtube."

I doubt YouTube videos are the main source for video editors.

We should clearly distinguish wrapper support from codec support.
Vegas Pro 17 does not support VP8/VP9 video codecs.
Vegas Pro 17 does support the MKV wrapper for file reading.

"The most common available MKV files would be 4k video from youtube."

I doubt YouTube videos are the main source for video editors.

We should clearly distinguish wrapper support from codec support.
Vegas Pro 17 does not support VP8/VP9 video codecs.
Vegas Pro 17 does support the MKV wrapper for file reading.

This is something I need to explore and am interested in. I'm currently holding off on VP17. I'm curious to understand that if I tried to put a MKV wrapper file which had Vegas supported video/audio codecs inside of it such as H264 AVC/AAC and if that MKV file contained multiple audio mix streams, then would Vegas be able to open that file on the timeline with the multiple audio streams placed on separate audio tracks?

Something I would love to do within Vegas is layoff multiple audio mixes into a MKV wrapper file container such as the full mix, music mix, sound Fx mix, Voice only mix, then be able to re-open that MKV wrapper file with those separate audio mixes appearing on separate audio tracks.

"The most common available MKV files would be 4k video from youtube."

I doubt YouTube videos are the main source for video editors.

We should clearly distinguish wrapper support from codec support.
Vegas Pro 17 does not support VP8/VP9 video codecs.
Vegas Pro 17 does support the MKV wrapper for file reading.

This is something I need to explore and am interested in. I'm currently holding off on VP17. I'm curious to understand that if I tried to put a MKV wrapper file which had Vegas supported video/audio codecs inside of it such as H264 AVC/AAC and if that MKV file contained multiple audio mix streams, then would Vegas be able to open that file on the timeline with the multiple audio streams placed on separate audio tracks?

Something I would love to do within Vegas is layoff multiple audio mixes into a MKV wrapper file container such as the full mix, music mix, sound Fx mix, Voice only mix, then be able to re-open that MKV wrapper file with those separate audio mixes appearing on separate audio tracks.

That you can do with AVI.

I have MKV clips containing AVC video and either AAC or AC3 audio stereo. At least these types work fine in VP17. Never tried multichannel MKV. Time to do.

That you can do with AVI.

Thank you! Optical format discs are dead or pretty much going that way in the very near future in my opinion. So I wish to work in file wrapper formats that have similar capabilities as BluRay but without the need to burn an optical disc. I didn't even bother to purchase a BluRay burner with my latest PC. I never realized AVI had that capability. I would still like to understand the Vegas limitations of opening MKV and how it handles the multiple audio stream capabilities of MKV.

I just tried to use an 8 channel MKV file in VP17 but it then reads only the first channel while the others are dropped.

Just a note, Happy Otter Import Assist now works with YouTube MKV / VP9 files.

That you can do with AVI.

Thank you! Optical format discs are dead or pretty much going that way in the very near future in my opinion. So I wish to work in file wrapper formats that have similar capabilities as BluRay but without the need to burn an optical disc. I didn't even bother to purchase a BluRay burner with my latest PC. I never realized AVI had that capability. I would still like to understand the Vegas limitations of opening MKV and how it handles the multiple audio stream capabilities of MKV.

I never used it on serious work though, just tried it out couple of times for fun sake. If I remember correctly you have to make some aux buses, then route your tracks accordingly, then, at the export you have to assign the buses...or something like that. Plus, you have a nice collection of audio and video codecs to choose from.

AVI's cool. 🙂

I just tried to use an 8 channel MKV file in VP17 but it then reads only the first channel while the others are dropped.

Thanks for trying it out and letting me know. That's kind of what I was afraid of would be the case. Bummer!

For MP4 the only (limited) support of multichannel in Vegas Pro is XDCAM EX with up to 4 channels.

X-AVC wrapped as MXF supports 8 channels.

XDCAM HD wrapped as MXF with up to 16 channels.

XDCAM SR wrapped as MXF with up to 24 channels.

And for AVI Vegas Pro supports up to 32 channels.

So at least there are some choices. Oops, offtopic.

That you can do with AVI.

Thank you! Optical format discs are dead or pretty much going that way in the very near future in my opinion. So I wish to work in file wrapper formats that have similar capabilities as BluRay but without the need to burn an optical disc. I didn't even bother to purchase a BluRay burner with my latest PC. I never realized AVI had that capability. I would still like to understand the Vegas limitations of opening MKV and how it handles the multiple audio stream capabilities of MKV.

I never used it on serious work though, just tried it out couple of times for fun sake. If I remember correctly you have to make some aux buses, then route your tracks accordingly, then, at the export you have to assign the buses...or something like that. Plus, you have a nice collection of audio and video codecs to choose from.

AVI's cool. 🙂

Thanks for the help. I always knew the MKV wrapper supported multiple channels of audio including surround formats as well as multiple channels of embedded subtitles and that was my interest in this topic and Vegas supporting it. It's sounding like AVI should be my preferred wrapper format but now I need to look into if my TV's media player also supports the audio track selection for playback of those different available audio tracks as well, where I'm thinking AVI likely has the best chance on that front. As long as the TV supported the codecs, I've always had the best luck with MP4, MKV, and AVI containers.

 Every video from 144p to 8k exists a vp9 mkv file. 

I'm not seeing it. Would love to see your basis and documentation for that notion.

I notice the mkv option with various YT downloaders. I do understand that downloaders are capable o muxing different codecs together so that mkv doesn't necessary exist on youtube. it's actually webm, remuxed into a mkv by downloader. The reason I don't believe this to be the case is that mkv and webm video files are different bitrates. Also mkv uses aac audio instead of opus. No re-encoding occurs after download 7 if it did, it would convert to hevc/avc and aac

The HOS inport option is useful. I don't have any experience with it, but as long as you can make certain the re-encoding creates a file no worse than the original YT version than that sounds like a valuable tool.

Please MAGIX, we need urgently edit WEBM and MKV formats with VP9 codec, including transparency.

Did anyone found a solution?

Yes, the solution is to use either HOS or Voukoder as Vegas renderer..

HOS or Voukoder are very interesting, but it seams only for rendering. I need to import a webm with alpha channel on the time-line and edit it.

WEBM is everywhere on the internet now. Because it's royalty free, it's more prevalent than MKV which vp17 does support. I guess the problem is that webm is usually vp9, and for some reason vegas can't read that. MKV is also very often VP9, but doesn't have to be

@Sirio

"HOS or Voukoder are very interesting, but it seams only for rendering."

You can also import Webm files into Vegas using the ImportAssist tool.

Thank you Wwaag, but this technique transcode the file, in this way I lose the alpha channel. I think that in 2020 Vegas must be able to edit webm files directly in the timeline.