For publications we currently offer two main types of downloadable encodes:
uses YUV color encoding, limited levels and 4:2:0 chroma.
MKV Modern HQ
uses YUV color encoding, full levels and 4:4:4 chroma.
With all the changes made to encoders and players alike over the recent years, Modern HQ just doesn't feel very "modern" any more. x264 has supported RGB for a long time, so my question is: why are we using 4:4:4 as our HQ option when we could be offering RGB? It would further separate the two encode types and we could still keep all the other (non-colorspace) settings identical and so the file size should theoretically be similar. The only difference is we'd be removing a needless RGB>YUV conversion from the process.
To be safe, I did a number of tests to see how x264 worked when handling lossless content in RGB. The resulting files (when decoded to RGB24) were identical to the same encodes produced with the Lagarith codec in RGB. Interestingly, I used this run
as my test and the resulting video stream (with no audio data) was 30.4mb. Combining that with FLAC audio leads to a final file size of 64.5mb (although this had no logo or subtitles), which gave me a second thought: Lossless RGB.
I'd love to see a third (optional, see below) encode option on publications for Lossless RGB. If I were not making encodes myself, it's the one I'd download
. Internet connections are getting faster and hard drive capacities larger. Digital retailers are selling music in lossless (and sometimes 24-bit) formats. Everything seems to be evolving in a very quality-driven manner and so I think we should too. Excluding detail changes (such as branch name) or errors, having Lossless RGB should prevent the need for any future encode updates and give people the best downloadable watching experience possible.
Regarding it being optional: I'd love to see this introduced as a standard for every publication on the site- but it's a huge task. Not every game is going to be able to get a lossless encode right away (3D games for instance, would be harder), and not everyone is going to be able to upload large files (Metroid was small, but longer encodes and more complex games could easily get large very fast). From an encoding perspective, it's another thing that's going to take time, although the good news is that the first pass (frame decimation) data generated for the Modern HQ can be re-used for the lossless encode to save time. Having said that, it would be nice to see some publications slowly pop up with "Lossless MKV" or some similar term as a third download option. Even if they're few in number to begin with, it would have to start somewhere.
I feel like at the very least we should have an RGB encode, whether it's new adjustment to the Modern HQ encode or a new lossless option.