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Wanted: a developer to solve GPU selection problem

Posted: 11 May 2020 13:22
by pbrook
Hi,
Our company is looking for a developer to make a change to libvlc to support passing GPU selection options to avcodec.
Here's what I understand about the problem.

ffmpeg can use two options to select the GPU that it wants to use for decode and encode. -hwaccel_device -gpu

Here's an example I tried with ffmpeg that I could control the encode but not the decode (the -hwaccel_device didn't do anything but the -gpu option after the nvenc... command did work.

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ffmpeg -hwaccel_device 1 -c:v h264_cuvid -i rtsp://admin:admin@192.168.0.87:554/stream0 -threads 1 -c:v h264_nvenc -gpu 1 -f mpegts udp://238.1.1.1:10101
here's the example that worked for decode and encode

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ffmpeg -gpu 1 -c:v h264_cuvid -i rtsp://admin:admin@192.168.0.87:554/stream0 -threads 1 -c:v h264_nvenc -gpu 1 -f mpegts udp://238.1.1.1:10101
I am using the libVLCSharp package to display a lot of camera streams in a .net application on windows. It requires multiple GPU support and I need to control and balance the decodes across several GPUs.

I was hoping to use the --avcodec-options command line options along with the -gpu i option for ffmpeg. However according to this topic:
How to load balance decoding on multiple GPUs? located here [url]https://forum.videolan.org/viewtopic.php?f=32&t=145015[/url]
VLC doesn't currently support passing these types of parameters to the ffmpeg avcodec library. I can confirm this from experience.

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vlc --avcodec_options="{gpu=0}" rtsp://admin:admin@192.168.0.87:554/stream0
I also tried various different syntax combinations but the above variation I believe is correct for a Windows command interface.

Please contact me if you are interested in doing the work. This is a development job for money - if the result is suitable for use in the VLC project then great otherwise we will use the version we get and not redistribute it. Also the time is pretty tight - we are using this application to preview loads on various hardware configurations for use with a production system that is still under development and isn't finished so we can't use it to determine the size of the hardware systems. We have to commit to a hardware configuration soon that is why we are building this test tool.

Re: Wanted: a developer to solve GPU selection problem

Posted: 11 May 2020 14:11
by mfkl
See https://videolabs.io/#contact (for libvlc and libvlcsharp devs).