Well at first hello everybody,
Normally I just follow up this thread like every day since Alpha 2 released but I think now it is time for a post.
It seems that there is quite confusion about the differences between RAW and YUV 4:2:2 uncompressed.
At first RAW and YUV 4:2:2 uncompressed are not the same!
From now on it is getting technically, who does not care can skip from here.
What is YUV 4:2:2 uncompressed.
YUV defines the color space. While the camera Sensor gives out RGB Signal, it is being converted to YUV.
Y = luminance which we get by adding 0,299R + 0,587G + 0,114B
U = Cr which contains R-Y
V = Cb which contains B-Y
Cr & Cb are the digital Forms of U & V and later only called Cr & Cb
So you can see that our RGB Signal is splitted up and G (Green) is completely left out, but because Y Contains part of the green signal we are able to convert YCrCb back to our RGB Signal (this happens in your TV, monitor or any other playout device).
However, what is 4:2:2?
4:2:2 defines the Chroma subsampling and is defined the following
4 stands for full resolution while 2 stands for half resolution, but what does that mean for us?
Y : 4 = 1920x1080 pixels
Cr(U) : 2 = 960x540 pixels
Cb(V) : 2 = 960x540 pixels
So you can see that our Chroma is recorded by only the half of the real resolution
Now you might think NO WAY I don't this but now it comes
We are currently shooting with our 7Ds at 4:2:0 which states that our movie clips look like this
Y = 1920x1080 pixels
Cr(U) = 480x270 pixels
Cb(V) = 480x270 pixels
So far with YCrCb 4:2:2 now the uncompressed.
Uncompressed just means that we have no compression (well that seemed to be clear)
Since we have no compression on our Video the bitrate is defined by the sampling and our quantization which is normally 8 or 10 bit
So the bitrate for uncompressed YCrCb 4:2:2 at 8 bit and 25 Fps is calculated by this:
(1920x1080x8)+ 2x(960x540x8) x 25 = 791Mbit/s = 99MB/s
So now you now what YUV 4:2:2 is.
Now to RAW
RAW is simple, it is just data from the sensor completely untouched (in theory) in real life you will have some sort of compression in it.
Differences between RAW and YUV 4:2:2
RAW have to be interpreted by some programm before edit / YUV can be edited immediately
RAW gives you the most possibilities (and the need) for color correction
With RAW you set you white balance in the post / With YUV you have a fix white balance
What for what
If once we get all features we would have Uncompressed YUV 4:2:2 at the HDMI Port to record with an external device and for internal ether an compressed YUV 4:2:2 or a compressed RAW
If there is already a post like this then I wasted my time.
If there is anything wrong please correct
If you find any mistakes you can eat them
Normally I just follow up this thread like every day since Alpha 2 released but I think now it is time for a post.
It seems that there is quite confusion about the differences between RAW and YUV 4:2:2 uncompressed.
At first RAW and YUV 4:2:2 uncompressed are not the same!
From now on it is getting technically, who does not care can skip from here.
What is YUV 4:2:2 uncompressed.
YUV defines the color space. While the camera Sensor gives out RGB Signal, it is being converted to YUV.
Y = luminance which we get by adding 0,299R + 0,587G + 0,114B
U = Cr which contains R-Y
V = Cb which contains B-Y
Cr & Cb are the digital Forms of U & V and later only called Cr & Cb
So you can see that our RGB Signal is splitted up and G (Green) is completely left out, but because Y Contains part of the green signal we are able to convert YCrCb back to our RGB Signal (this happens in your TV, monitor or any other playout device).
However, what is 4:2:2?
4:2:2 defines the Chroma subsampling and is defined the following
4 stands for full resolution while 2 stands for half resolution, but what does that mean for us?
Y : 4 = 1920x1080 pixels
Cr(U) : 2 = 960x540 pixels
Cb(V) : 2 = 960x540 pixels
So you can see that our Chroma is recorded by only the half of the real resolution
Now you might think NO WAY I don't this but now it comes
We are currently shooting with our 7Ds at 4:2:0 which states that our movie clips look like this
Y = 1920x1080 pixels
Cr(U) = 480x270 pixels
Cb(V) = 480x270 pixels
So far with YCrCb 4:2:2 now the uncompressed.
Uncompressed just means that we have no compression (well that seemed to be clear)
Since we have no compression on our Video the bitrate is defined by the sampling and our quantization which is normally 8 or 10 bit
So the bitrate for uncompressed YCrCb 4:2:2 at 8 bit and 25 Fps is calculated by this:
(1920x1080x8)+ 2x(960x540x8) x 25 = 791Mbit/s = 99MB/s
So now you now what YUV 4:2:2 is.
Now to RAW
RAW is simple, it is just data from the sensor completely untouched (in theory) in real life you will have some sort of compression in it.
Differences between RAW and YUV 4:2:2
RAW have to be interpreted by some programm before edit / YUV can be edited immediately
RAW gives you the most possibilities (and the need) for color correction
With RAW you set you white balance in the post / With YUV you have a fix white balance
What for what
If once we get all features we would have Uncompressed YUV 4:2:2 at the HDMI Port to record with an external device and for internal ether an compressed YUV 4:2:2 or a compressed RAW
If there is already a post like this then I wasted my time.
If there is anything wrong please correct
If you find any mistakes you can eat them