2K and 422 color space: Maybe for sub $1000?

[FilmMan]

I'm getting a little excited here. Magic Lantern Programmer 1% and others have been making some progress and talking about 2K and 422 color space. It is premature but worthy of mentioning again - In case you haven't been following the [color=#FF0000][b]115 mbp/s??? CANON DSLR link (read the 2nd last post on the link).[/b][/color] [url="http://www.eoshd.com/comments/topic/1203-115-mbps-canon-dslr/page__st__20"]http://www.eoshd.com/comments/topic/1203-115-mbps-canon-dslr/page__st__20[/url]

Why do I say sub $1000? Well, programmer 1% has been tweaking his 600d which is priced as low as $480!!!
[url="http://www.myshopping.com.au/PR--384480_Canon_600D_Camera"]http://www.myshopping.com.au/PR--384480_Canon_600D_Camera[/url]

It is still early. Here's some conversation from 1%...

[color=#0000FF][i] 4:2:2 already being thrown away. 2k is just next size up. If the frames can compress < card rate should be possible. Will probably need to be zoomed to not have line skip. It was probably the only way to fit 20MP sensor in <3MP video[/i].[/color]

Donating $5 to $10 to their cause at Magic Lantern would probably go a long way.

[FilmMan]

Here's the 2nd last post. It is a good read so I'm being repetitive here. This is from the programmer 1%. He was responding to "because there is no interframe dependence"

[b]Quote[/b]
[indent=1][b]because there is no interframe dependence[/b][/indent]



[b][i]Yep, I frame dropped from buffer almost immediately. P frame sticks around for a while while its doing more passes, etc.

The P frames are only a little bit more compressed and really the main reason to use them is file size/buffer. 1GB a minute is hardcore no matter how you do it. Also, no B frames yet... Gop3 is where its closer to old file sizes and doesn't write almost all the time. I think the I frame has to be like 10-15% bigger for the same quality so instead of a decent 130mbps you end up at 160-170mbps and you actually do crash if the encoder slows down or the card does. Should test gop of 2,3-6... any more than that and too much is held in the buffer.

Qscale drops like a stone when the buffer warning comes on but it ramps up right away with the faster polling. You can turn on debugging and watch it. Qscale with canon functions only moved by one. With slice you can go from 128 to 87 instantly. [color=#FF0000]I think canon was really going for consumers and smaller files rather than quality. They want you to buy a more expensive camera rather than using a 600D, etc. [/color]The weird thing is that they don't like offering swappable lenses on their camcorder offerings. Heavy grading will really show if the bit rate dips matter or not. If a few frames get all funky out of a whole sequence then we'll know.


Other cameras:

50D = Did not change gop.
550D = no breaking 4gb limit so you'll have all of 4 minutes of footage.
60D = untested for both limit and gop.
T3 = can probably pull it off
5d3 = different encoder, different hacks
5d2 = don't have one and nobody has really looked in on it. Encoder also slightly different. CF cards should in theory do more than 20MB/s write. A1ex has one so he'd be the guy to try it. But still have to hack the 4gb limit and 5d2 is the same generation as 550D so maybe only 32bit value for file size [img]http://www.magiclantern.fm/forum/Smileys/default/sad.gif[/img]

What's left?

MJPEG might end up giving better results and actual full frame video, none of this 1600x960 crap. Although maybe native recording and resizing later might give better results for regular H.264 than in camera resized 1920x1080. [color=#FF0000][size=6][u][u]I can continually take shots at S1 which is like 2592x1728 so 2k video seems possible. [/u][/u][/size]Ma[/color]x file size per frame would be like .83MB to get 24p out of that. .67 for 30P... not a whole lot of room. SD interface max speed at 48mhz is 25MB but no card seems to want to keep up. How good can you get at that data rate?

Line skip is likely so it can fit the entire frame into reduced resolution without resizing the whole image and taking up CPU time, etc. It IS controllable since 600D has 1:1 crop and even zooming. But the issue will be that the frames are bigger and more complex to encode.. hence static and trees are very evil.

Right now, encoder in the hand is worth 2 in the theoretical stage. [/i][/b]