10bit encoding (x265)

Suggestion
1

Hello,
Is there a solution to use 10bit x265 encoder?
I don’t find how i can full custom ffmpeg export, not only preset, and don’t find it on this forum.

(alternatively finding a superfast (more than 90fps) codec/param for doing my encoding in a second step on ffmpeg, but it’s a bit stupid)

Image quality of libx265 10bit (for 8bit display and 8bit video source) is WAY BETTER than x265 8bit. 10bit remove posterisation, it’s a revolution, it’s important to export all your projects in 10bit. (x265,vp9,av1)
I think we need to ban 8bit codec from all encoders in the world (except H264 codec because hardware decoding don’t support 10bit :/)

i use this command on ffmpeg:
ffmpeg.exe -i input.mp4 -c:v libx265 -preset medium -crf 25 -qcomp 0.75 -pix_fmt yuv420p10le -x265-params keyint=300 -c:a libopus -b:a 160K output.mkv

Thank you :slight_smile:

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2

It does not make sense until the engine internals can handle 10-bit, but currently it is 8-bit. BTW, you can already export in 10-bit with x265 in Advanced if you know what you are doing. Search here. I answered it already elsewhere.

3

Sorry, we only have 10-bit currently for x264 when you put the following in Export > Other

mlt_image_format=rgb24
pix_fmt=yuv420p10le

We probably simply need a build-time configure option for x265.

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4

Ok thank you, it works with libx264 :slight_smile:
I see shotcut use libx265.dll to work.
I don’t know how to build it, i only know building a full ffmpeg.exe with all lib included.

The reason why 10bit for export is: not to have real 10bit, it’s because 8bit codec are all BAD to encode good 8bit color gradient (even AV1 codec) (however it’s good with very high bitrate). That makes sense for 8bit source and workflow.

5

My response above also works for x265 in Windows as of version 20.10.31. I am adding the x265 configure option to the Linux and macOS builds for the next version.

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6

The option that works for me is

pix_fmt=p010le

It produces the following info

Video
ID                          : 1
Format                      : HEVC
Format/Info                 : High Efficiency Video Coding
Format profile              : Main 10@L4@Main
Codec ID                    : V_MPEGH/ISO/HEVC
...
Color space                 : YUV
Chroma subsampling          : 4:2:0
Bit depth                   : 10 bits

No color banding now. I’m so happy. ^^

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