[Lossless] Ut Video Codec

[Zarxrax]

Here are some hard numbers on the performance of this codec.
Test video is the movie My Neighbor Totoro, 848x480. I think this is a good real-world test clip.

UTvideo (better decoding speed)
Size: 30.1GB
Decode time: 187fps

UTvideo (better compression)
Size: 24.1GB
Decode time: 177fps

Lagarith
Size: 22.5GB
Decode time: 68fps

Huffyuv (Plane)
Size: 24.9GB
Decode time: 158fps


As you can see, UTvideo gives you quite some flexibility with its two different modes. The fast decode speed version was about 25% larger than the high compression version. The high compression version was about 7% larger than lagarith. This *might* be a big deal for some people, but I think at the large filesizes we are working with here, a 7% difference isn't very major.

As for decoding speed, the difference speaks for itself. For UTvideo, I strongly suspect that for both files, it was in fact being limited by the transfer speed of my hard disk. In other tests I have done, the high decode speed version actually outperforms the high compression version by about 30%.

Because both UTvideo clips maxed out my hard disk, there is absolutely no reason for me to even consider the fast decoding one. The high compression version is plenty fast already. Note that UTvideo performed 260% faster than Lagarith.
The high compression version of UTvideo also outperforms Huffyuv in both speed and filesize.

[Cannonaire]

Thanks for the numbers, Zarx! I probably wouldn't have run tests on that myself. This means I can stop using the fast decode option.

Although thinking about it, if you're doing a lot of heavy editing with effects taking a lot of CPU time, it might be nice using the fast decode over compressibility.

[Cannonaire]

Just an update, UTVideo 422 plays smoothly in Vegas (I'm using Vegas Movie Studio 10).

I haven't tried 420 because of various issues, but 422 is not having the same speed issues as I had with other YUV codecs in Vegas. Huzzah!

[Mister Hatt]

Something worth noting seeing as people are using lossless and this kinda makes lossless entirely not worthwhile: when you resample your chroma in smaller blocks (2x1 blocks of chroma rather than 2x2 - it's what happens when you 4:2:2 instead of 4:2:0), you are doing so losslessly as it just uses the same chroma value. However any effects and whatnot that you apply will be rendered in a 4:2:2 chroma space, which when you encode is resampled to 4:2:0 and you thus lose colour definition. This can cause anything from blocky jaggies to banding to blurring on any chroma edges. If you are exporting, make sure you render your effects at 4:2:0. x264 CAN support 4:2:2 but at this point in time it doesn't. Just a heads up.

[Cannonaire]

Thanks for the good advice, Mister Hatt.

That kinda messes up the way I was planning on doing things moving forward. From what I can tell, Vegas processes everything internally in RGB, but if I understand correctly it will pass unprocessed YCbCr stuff straight through. So basically as long as I just do straight cuts and no effects (lol) it will maintain the original quality. That really sucks... not to mention the color inconsistencies created when some stuff is processed and other stuff isn't. I'm starting to see why some people don't like Vegas. At the risk of getting slightly off-topic, does Premiere do this any better? I also read that After Effects processes in all RGB as well.

Lastly (and more on topic), UTVideo 420 seems to be working fine for me now, so hurray for smaller files!

[Mister Hatt]

I have no idea how Premiere does it but I could ask around. Obviously it will have the same resampling problems as there is no way around that, but as far as RGB conversions go I would imagine that it picks a matrix either arbitrarily or based on vertical resolution and is consistant with that.

[Cannonaire]

I stumbled upon what I think is the reason UTVideo 420 wasn't working for me. Neither 420 nor 422 will play back in anything aside from VirtualDub for me if they are not mod16. Tested using a 720x480 video clip, cropped it to 712x480 and 704x480 and saved both with the same UTVideo settings (actually, I saved them both twice, with 420 and 422). The 704x480 files will all play normally, but none of the 712x480 files will play in anything other than VirtualDub.

Is it specified somewhere that UTVideo resolution must be mod16?

[mirkosp]

I have no idea how Premiere does it but I could ask around. Obviously it will have the same resampling problems as there is no way around that, but as far as RGB conversions go I would imagine that it picks a matrix either arbitrarily or based on vertical resolution and is consistant with that.

Premiere acts a bit differently. Some effects are YUV and others are RGB (from what I saw of CS5, this is especially stated for each effect), so depending on the colourspace of the clips and effects you use, you might be able to get the whole thing through without a colourspace correction.

[BasharOfTheAges]

How noticeable would these conversions be? Are we talking the visual equivalent of an audiophile claiming to be able to tell which kind of speaker wire you're using? Something that'd be less important than the temperature of your monitor (or even the lighting in the room) on color? Or something normal people would actually notice?

[Zarxrax]

How noticeable would these conversions be? Are we talking the visual equivalent of an audiophile claiming to be able to tell which kind of speaker wire you're using? Something that'd be less important than the temperature of your monitor (or even the lighting in the room) on color? Or something normal people would actually notice?

Normal people can't even notice an incorrect aspect ratio, so I think this is not a problem