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Cineform: YUV 10 Bit or RGB 12 bit

Guarino
By Guarino
in Photography and Videography
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Go to solution Solved by mariushm,

The quality difference between 10bit and 12bit will be extremely small, but the software will be much slower in general... it's not worth it.

 

With 10 bit per color/element it's possible for software to make lots of optimizations, for example they can pack a pixel into a 32 bit variable  ( 3 x 10 bit + 2 bits padding) and it also makes it possible to do much faster conversions between YCbCr 4:4:4 to 4:2:2 or 4:2:0  ... these conversions work with groups of 4 pixels so it's super easy to just play around with 32 bit blocks of data, or put 4 x 30 = 120 bits into 16 bytes ( 15 x 8 = 120 bits + 8 bits of padding for a nice round 16 bytes)

 

Having 32bit chunks of stuff makes it possible to process blocks of image with instructions like SSE and AVX more easily compared to 12 bit formats, and it also makes it easy to "upload" data to video cards - think faking the 10bit image as a texture with 32 bit per pixel (3 x 8bit per pixel + 8 bit transparency) and applying shaders and opencl magic on the texture/data for hardware acceleration)

 

with 12bit each pixel is 36 bits, so it must be packed into a 5 byte variable (actually most software at this point will just use 2 bytes per color/element) so lots of things are simply much slower.

 

 

Posted

@.spider. @AkiraDaarkst @mariushm

 

I tried playing the IMAX 10bit h264 and the Sony XAVC sample on my HDR TV  ....

 

IMAX plays with artifacts and skips

the Sony sample doesn't play at all

 

I took a look at h.264 official spec sheet https://www.itu.int/rec/dologin_pub.asp?lang=e&id=T-REC-H.264-201610-I!!PDF-E&type=items

and it only lists rec.2020  and rec.2100

 

those two files do not use standard h264 encoding

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16 minutes ago, zMeul said:

 

The sample XAVC files you downloaded from the link I posted, as I said, are not post-processed files.  They are straight out of the camera master files, without the necessary metadata for HDR playback.

 

If you want to play back HDR footage on your HDR TV, you need the correct metadata.  That means taking the footage you downloaded and post-processing them through either Premiere Pro or DaVinci Resolve's HDR workflow and finally rendering out a version that will be played back as HDR on your TV.  If you use a non-HDR workflow, the rendered file will be a SDR version.

 

Also, I'm not certain your TV (without being connected to a computer and treated as an external monitor to said computer) has the capability to play back XAVC files in an MXF container.

That is not dead which can eternal lie.  And with strange aeons even death may die. - The Call of Cthulhu

A university is not a "safe space". If you need a safe space, leave, go home, hug your teddy & suck your thumb until ready for university.  - Richard Dawkins

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5 minutes ago, AkiraDaarkst said:

The sample XAVC files you downloaded from the link I posted, as I said, are not post-processed files.  They are straight out of the camera master files, without the necessary metadata for HDR playback.

 

If you want to play back HDR footage on your HDR TV, you need the correct metadata.  That means taking the footage you downloaded and post-processing them through either Premiere Pro or DaVinci Resolve's HDR workflow and finally rendering out a version that will be played back as HDR on your TV.  If you use a non-HDR workflow, the rendered file will be a SDR version.

 

Also, I'm not certain your TV (without being connected to a computer and treated as an external monitor to said computer) has the capability to play back XAVC files in an MXF container.

the idea was h.264 10bit as end-user consumer format

neither of the samples found, one RAW one processed, are standard h264 

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Posted

If you want to create an HDR metadata embedded version of the XAVC sample files you downloaded, here is the workflow in Premiere:

  • Create a new timeline sequence in Premiere with the video file
  • Make sure the timeline sequence window is selected and then go to File > Export > Media
  • Select HEVC or JPEG 2000 as the format (I recommend HEVC)
  • In the Video tab below, uncheck the box next to Main 10 (which is greyed out), and then select Main 10
  • Check Rec.2020 Color Primaries and this should also enable/check the High Dynamic Range option below it
  • Export the video, and then take it to your HDR TV to watch it

 

Read this article to see what you need to do in DaVinci Resolve to embed HDR metadata.

https://support.google.com/youtube/answer/7126552?hl=en

That is not dead which can eternal lie.  And with strange aeons even death may die. - The Call of Cthulhu

A university is not a "safe space". If you need a safe space, leave, go home, hug your teddy & suck your thumb until ready for university.  - Richard Dawkins

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5 minutes ago, zMeul said:

the idea was h.264 10bit as end-user consumer format

neither of the samples found, one RAW one processed, are standard h264 

Oh you wanted end user versions, the link I gave you were versions before that stage.

 

There are HDR sample video files on Youtube you can try watching on your HDR TV.

That is not dead which can eternal lie.  And with strange aeons even death may die. - The Call of Cthulhu

A university is not a "safe space". If you need a safe space, leave, go home, hug your teddy & suck your thumb until ready for university.  - Richard Dawkins

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4 minutes ago, AkiraDaarkst said:

There are HDR sample video files on Youtube you can try watching on your HDR TV.

I tried those YT samples, but I don't think they're encoded correctly as it doesn't switch the TV in HDR mode as it does with proper rec.2020 files

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33 minutes ago, zMeul said:

I tried those YT samples, but I don't think they're encoded correctly as it doesn't switch the TV in HDR mode as it does with proper rec.2020 files

What TV model do you have?  Also how are you watching those YouTube HDR samples?  The HDR TV I want for my studio hasn't arrived yet so I don't know how it needs to be set up, but I assume for YouTube the TV needs to have some sort of native YouTube app/player and not be connected to the computer as an external monitor.

 

Try these

 

That is not dead which can eternal lie.  And with strange aeons even death may die. - The Call of Cthulhu

A university is not a "safe space". If you need a safe space, leave, go home, hug your teddy & suck your thumb until ready for university.  - Richard Dawkins

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13 minutes ago, AkiraDaarkst said:

What TV model do you have?  Also how are you watching those YouTube HDR samples?  The HDR TV I want for my studio hasn't arrived yet so I don't know how it needs to be set up, but I assume for YouTube the TV needs to have some sort of native YouTube app/player and not be connected to the computer as an external monitor.

 

Try these

 

yes those, do not switch the TV in HDR mode; and I barely see any difference if I play them on the PC (8bit monitor)

yes, the TV has it's own YT app

 

I play rec.2020 sample files directly from the storage (network DLNA or USB drive)

 

when the TV encounters HDR content it switches to HDR mode, with new menus and a big identifying logo on the top right corner

 

TV model: LG UH603V

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10 minutes ago, zMeul said:

yes those, do not switch the TV in HDR mode; and I barely see any difference if I play them on the PC (8bit monitor)

yes, the TV has it's own YT app

 

I play rec.2020 sample files directly from the storage (network or USB drive)

 

when the TV encounters HDR content it switches to HDR mode, with new menus and a big identifying logo on the top right corner

 

TV model: LG UH603V

YouTube doesn't even indicate whether you are watching HDR versions of those videos?  They should show an indicator somewhere.

 

OK I will get back to you when my TV arrives and I'm able to test some settings for myself.  For the moment, I can't give you any additional help.

That is not dead which can eternal lie.  And with strange aeons even death may die. - The Call of Cthulhu

A university is not a "safe space". If you need a safe space, leave, go home, hug your teddy & suck your thumb until ready for university.  - Richard Dawkins

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6 minutes ago, AkiraDaarkst said:

YouTube doesn't even indicate whether you are watching HDR versions of those videos?  They should show an indicator somewhere.

nope

 

I seriously doubt YT even has correct parsing of HDR metadata

I tried uploading HEVC main10 samples to YT, with and without HDR metadata, and it fails to process

 

I don't have Premiere, I can't afford it

I do my testing with 3rd party samples from wherever I can

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Posted

Youtube has HDR , but basically the videos are available only as VP9 Profile 2 encodes , and a lot of TVs don't support this codec in hardware, so they'll fall back to regular HD. 

 

Here's a video :

 

It falls back automatically to SDR versions of the video if you play it without HDR monitor/tv so if you want to actually download the HDR versions of the video from Youtube, you need to use youtube-dl or some extension.

 

I have some of these videos with HDR data on my ftp server here : ftp://helpedia.com/pub/multimedia/testvideos/

 

The ones with VP9 Profile 2 in name are definitely encoded in bt2020 with HDR metadata :

* The World in HDR 4k 59.94 fps (VP9 Profile 2 HDR).mkv 

* The Redwoods 4k 24fps (VP9 Profile 2 HDR).mkv

 

Sony 4K HDR Camp.mkv is also bt2020 with HDR metadata but encoded in HEVC. It's great demo video, could barely play it in software but decodes smooth as butter in hardware on my RX470.

 

Exodus_UHD_HDR_Exodus_draft.mp4  is a nice example of movie encoded with HDR data, you should be able to see differences between SDR and HDR

Life of PI sample in the same folder is also a great example of HDR, but again it's HEVC encoded

 

If you want you can also check in testvideos/hevc/ the video : Samsung_SUHD_Picture_Quality Demo_Nano_Crystal Display_UK-Version_10bit_bt2020_avg50mbps.mp4  but i'm not sure it has the HDR signaling (metadata).

 

 

 

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