Values clarification

[jriker1]

I was curious when using rav1e stand alone app, a few things:

1. is there a value to define for Chroma Position like Topleft or something? Didn't see it in the default output of the app.
2. How do you determine what to enter for the tiles value?
3. Is HDR matrix value the same as what I'm used to with HEVC of color space?
4. Seen some people reference pixel format with -pix_fmt yuv420p10le but do not see it in the again default output of the app thoughts?
5. How does rav1e deal with quality of output? Do not see an option for setting like crf values.

Here is where I'm at right now for a sample of a 4k HDR10 format video I am converting with AV1 codec. Thoughts?

rav1e.exe input.mkv --threads 30 --speed 3 --quantizer 50 --tiles 16 --keyint 24 --range limited --primaries=BT2020 --transfer=SMPTE2084 --matrix=bt2020nc --mastering-display=G(13250,34500)B(7500,3000)R(34000,16000)WP(15635,16450)L(10000000,1) --content-light=1016,115 -o out.ivf

Theory is:

Speed 3 for a really like it video at higher quality and 6 for basic backup
Quantizer 50 for HQ and 90 for basic backup

Note if relevant I'm running a Ryzen 7950x CPU with 64GB ram and right now no GPU other than the one in the MB.

[shssoichiro]

1. There currently isn't
2. Tiles are a tradeoff between speed (both encode and decode speed) and quality. The general recommendation is to use as few tiles as you can get away with, usually 1 tile for anything below 1080p, 1-2 tiles 1080p, 2 tiles for 1440p, 4-8 tiles for 4k. Tiles has to be a power of 2.
3. The values should be similar, they may be slightly different as far as capitalization or whatever. rav1e --help can give a full list of options
4. This is an option in av1an and not actually in rav1e itself
5. --quantizer is the equivalent of crf in rav1e

[jriker1]

Thanks for the quick reply. How do you pull up a list of the matrix values? Doing just rav1e --help only shows a list of parameters not their potential values. More interested now if they are case sensitive.

Wasn't sure on my question 4 if there isn't an option then for pixel format? Also with chroma position how would I set this then or should I avoid encoding videos at this point if that's not something I can set?

Can't find the available values in the command line app help or otherwise for matrix but did find this in one of the issues and that didn't error "--matrix BT2020NCL" however most of my videos have a color space of "bt2020nc" so not sure if that's the same or what.

[shssoichiro]

Oh, huh... at one point I'm pretty sure it showed the values, I guess that broke at some point... I opened #3146 to track this.

Regarding the pixel format, rav1e assumes you want the output pixel format to be the same as the input. Likewise for chroma position, it assumes you want the output to be the same as the input. If you need to modify these, the best way is to use a tool like ffmpeg or vapoursynth to pipe in the modified input to rav1e.

[jriker1]

Thanks, what about my inquiry on available matrix values? Bringing down to here and reword:

Most of my videos have a color space of BT2020NC. That seems to error when I set "--matrix BT2020NC". It doesn't complain if I set "--matrix BT2020NCL". Not sure I know the difference or impact setting a different value between NC and NCL.

One last one hopefully. You can't process mkv files? I get:

Could not parse input video. Is it a y4m

Believe the answer is that's it but thought it odd that only an uncompressed format would be supported?

Brutal. Think I'm going to call it a day or something. Is this accurate and please review the above to:

1. In order to use rav1e I would need to convert my video into like some 6+ TB y4m file?
2. If I want to use ffmpeg instead with the library there, currently mastering-display and content-light aren't passed so can't use it.