Dual GPU encoding

Questions and answers on how to get the most out of FFAStrans
Posts: 9
Joined: Wed Jul 18, 2018 4:57 pm

Re: Dual GPU encoding

Post by llittleton » Wed Jul 29, 2020 6:40 pm

I have been trying out using Rigaya's Nvencc:


Using this command line:

%comspec% /c "D:\NVEncC_5.11_x64\NVEncC64.exe -i "%s_source%" --fps 30000/1001 --output-res 1920x1080 -c hevc --cbr 10000 --lookahead 16 --aq --profile main10 --output-depth 10 --audio-codec aac --vpp-edgelevel --vpp-deband --video-tag hvc1 --cuda-schedule auto -o "%s_original_path%\%s_original_name%_HD.mp4""

The advantage is that it enables gpu decode and encode for HEVC 10bit, plus it load balances on both Nvidia P4000 Gpus!

XAVC-I UHD 60 H264 10 bit to UHD 30 HEVC 10 bit runs at 30 fps (no gpu decode), can run 2 - 3 sessions.
UHD 30 HEVC 10bit to HD 30 HEVC 10bit runs at 170 fps (the above command line). can run 4 - 6 sessions.
HD 30 HEVC 10bit to 720p runs at 300 fps, can run 8 - 12 sessions.

Good so far! It would be of great benefit to be able to specify the max jobs per workflow.

I have not figured out how to limit the number of audio channels with this workflow, all 8 audio channels are passed to the output videos.
I really only need to keep the first two audio channels. Rigaya's documentation is not clear on audio options.

Thanks again,


Posts: 656
Joined: Wed Sep 19, 2018 8:11 am

Re: Dual GPU encoding

Post by emcodem » Thu Jul 30, 2020 12:10 pm

hey @littleton

Here is a small hack that allows you to control the jobs per workflow.
viewtopic.php?f=5&t=875&p=5384&hilit=li ... face#p5387

As a result of this thread, we already experimented with smarter queue controls and are making our way slowly. There are many things to take into consideration for smart que management, it could take a while...

Regarding the audio channel config, unfortunately i cannot help you, never heared of the tool you are using. Maybe you can port it to ffmpeg at some time, then it will be easy to help you ;-) Also you could probably pipe the output of your tool to ffmpeg and take care about the audios there... or run ffmpeg with -c:v copy after your tool finished the encoding, taking care about the audios only.

Posts: 9
Joined: Wed Jul 18, 2018 4:57 pm

Re: Dual GPU encoding

Post by llittleton » Sat Aug 01, 2020 5:43 pm


Thank you for your reply. I will look at the workflow hack and will try your suggestion of an ffmpeg node to strip out the audio channels.


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