Blocks/pixelation in every compression.

[Dillon Novak]

I have a 1920X1080 ProRes with Alpha 4444 master that my colorist gave me and no matter how I compress the file I get Blocks/pixelation in the background. I have no idea what is going wrong.

Here's a h.264 @ 5000 kbps

And here's the original prores

Any help would be appreciated.

 

[Stephen Strangways]

You have very smooth gradients in the background, so ProRes, being 10-bit and lightly compressed is able to handle it easily.
Compressing it to an 8-bit format like H.264 means there are fewer tones to represent those gradients, so you get posterization, and then the heavy compression turns it into blocks.

What you need is an encoder that does dithering in the 10-bit to 8-bit conversion process. I have no idea if there are any simple, non-proprietary tools for that, but you could try running it through AviSynth with GradFun2db on a Windows machine:
http://forum.doom9.org/showthread.php?t=108681

Or, on the simpler side, use a filter to add grain or monochrome noise to your footage before encoding.

 

[Tom.Wong]

yep, stephen is right. (4x4 i believe is 12 bit btw) pro res 4x4 with all that info is being crammed in a 8 bit format. there is only so much the 8 bit codec and retain. plus you are also limiting the bandwidth at 5000 kbps, which will further reduce the amount of information and the increase in artifacts. you tend to lose color temp, saturation, and subtlety overall when you compress it down like that. it's gonna be a no win situation unless you go more advanced non commercial routes like Stephen suggested. or put less compression on it.

 

[Stephen Strangways]

You could also try encoding directly from your ProRes file or a 10-bit Uncompressed file using x264 at the High10 profile, which is 10-bit. Not all players can play it back though, so it depends on where you are delivering it. Advanced users with up-to-date copies of VLC? No problem. People who are not computer-savvy and have old versions of the players that came with their OS? They could have problems. Devices like iPods? It's hard to say without testing each device.

So how do you encode to x264 High10? Well, MediaCoder will do it.
The Main Concept encoder in recent versions of Adobe's software might do it.
Handbrake might do it.

 

[James Drake]

Or just avoid h.264 altogether and use Redray. when it gets here anyway

 

[Dillon Novak]

Right, but cheack out these guys' video. It looks SO crystal clear. It's RED MX just like ours.

http://www.youtube.com/watch?v=HyfwYe5SfKY

The video looks as sharp as my prores, but any compression for youtube I do is terrible in comparison.

 

[Stephen Strangways]

It's entirely subject matter. His video has no smooth gradients. Yours does.

 

[Luca Immesi]

Try to make an h264 with adobe media encoder cs5, format: h264, enable render at maximum bit depth, 2 pass vbr.