latridutou wrote:Andrew Kolakowski wrote:3:1 compression
Source of this info?
Andrew Kolakowski wrote:There is no open source/universal RAW format atm. and probably there never will be one.
That's a pretty pessimistic view of the future and the present as well. Also a format might not be "open source", but be more open about its internals,
ARRIRAW for example.
Official papers. Look at graphs like this:
You have uncompressed rate and ProResRAW- simple math and you have compression ratio.
Arri RAW is plain uncompressed RAW+ very rich metadata around it. Everyone can use uncompressed RAW but then you have to deal with huge data rate and things gets complicated when it comes to storing it. Uncompressed RAW is easy, but hits you in storage needs and this is why you have BRAW, ProResRAW etc.
3:1 is sweet spot for high-end and anything like 5:1 or even 8:1 is good for less demanding shooting.
There is nothing complex in BRAW or ProResRAW ( same as with ProRes/DNxHR etc.) Those are quite simple codecs at the end.
Key difference is that ProResRAW allows you to access RAW pixels over SDK (there is already ProResRAW to CDNG RAW converter) and BRAW doesn't (as it pre-processes them which allows to avoid RED patent). RAW recording can use about any current codec if you really want eg. h264. It's just simple B&W data. No one went step ahead though and tried to write properly optimised codec for RAW. I think it's possible as Bayer pattern has known structure and you could use this in order to make codec which is specifically targeted for RAW. It may also end up you can gain eg. 5-10% data rate which may not be worth whole hassle.
BM atm. shows no interest in sharing BRAW encoding, so they have no reason to describe its internals.
ProResRAW is also not so "open" (ATOMOS pays special role here) so no extra details about it either. Everyone tries to make a $, so don't expect much to be changed any time soon.
Open source is not necessarily an answer to every problem in post. Open source also needs to be looked after and quite often after few years there is no one interested anymore (as it's all driven by passion mainly) and it simply dies.