macOS HEVC Main10 Hardware Encoding

[tunesify]

Are there any Macs that support 10-bit (Main10 Profile) HEVC (H.265) encoding with hardware acceleration in the VideoToolbox framework? Someone created an Open Source command-line tool that lists all the supported profiles: https://github.com/8birds/VTEncoderInfo
Even on a 16" MBP with a Radeon Pro 5500M it can only do HEVC_Main10_AutoLevel in software (SW), not hardware (HW or AVE) which is limited to HEVC_Main_AutoLevel. Would anyone with another device be willing to see what they can do? Maybe the iMac Pro or Mac Pro would be possible candidates?

Alternatively, if you have FFmpeg installed you could run:

ffmpeg -i [input_file] -c:v hevc_videotoolbox -profile:v main10 -tag:v hvc1 \
    -b:v 10000k -an -sn [output_filename].mp4

When I do that I see:
[hevc_videotoolbox @ 0x7f93d7801600] Error: cannot create compression session: -12908 [hevc_videotoolbox @ 0x7f93d7801600] Try -allow_sw 1. The hardware encoder may be busy, or not supported. Error initializing output stream 0:0 -- Error while opening encoder for output stream #0:0 - maybe incorrect parameters such as bit_rate, rate, width or height

Adding -allow_sw 1 does allow it to use the software HEVC encoder but it's brutally slow.

Thanks!

 

[bluEmaP1E]

IMHO, macos usually only use igpu to decode and encode video. Intel igpu only supports 8bit encoding since skylake.

 

[pianojoe]

My 2018 Macbook Pro (with a Radeon Pro 560X 4 GB) has no problem encoding Main10 in hardware. And it’s really fast. However, quality is mediocre, especially at low bitrates. Since I’m usually not in a hurry, libx265 is the way to go!

 

[jaromirrivera]

It looks like Big Sur adds 10-bit hardware encoding via Intel GPUs (QuickSync) to Apple's VideoToolbox framework. I have a 2018 MacBook Pro and only 10-bit software encoding was available and T2 hardware encoding quality was terrible. Since updating to Big Sur my encodes using https://github.com/donmelton/other_video_transcoding have been faster with great quality.

 

[Ritsuka]

You should check if the output file are actually 10-bit. FFmpeg might ignore the main10 profile and fallback to 8-bit.

 

[jaromirrivera]

You should check if the output file are actually 10-bit. FFmpeg might ignore the main10 profile and fallback to 8-bit.

Yeah I was able to verify that, I was encoding an HDR 10-bit video and was able to playback the encoded file in Plex with HDR enabled as well. (8-bit video does not support HDR)

 

[eugenios]

Hello everyone,
I'm doing some encoding test to understand better the HW capability of my iMac 2019 with AMD Radeon 48.
I red a lot of forum, blog etc. but I didn't found a clear explanation on how to use the Radeon to encode HEVC.
More in details I tested with Handbrake (H265 10bit Videotoolbox) and the GPU% shown by Activiy monitor was at max 12% while instead using Apple Compressor GPU% reached up to 85% (together with some hangs of iMac the graphic UI).
Anyone knows why those differences?