Recorder component ffmpeg error on gt740/h264_nvenc in container: No capable devices found

[bsyomov]

After some debug, error is: "lossless encoding not supported" Seems like this ffmpeg bug: https://trac.ffmpeg.org/ticket/9165 - some trouble with presets.

This command works on my host(debian 10, quite old ffmpeg), but not in container: ffmpeg -hide_banner -loglevel verbose -y -i /recordings/test.mp4 -c:v h264_nvenc -pix_fmt nv12 -movflags +faststart /recordings/test1.mp4

on host:

[h264_nvenc @ 0x559fde814240] Loaded Nvenc version 11.1
[h264_nvenc @ 0x559fde814240] Nvenc initialized successfully
[h264_nvenc @ 0x559fde814240] 1 CUDA capable devices found
[h264_nvenc @ 0x559fde814240] [ GPU #0 - < NVIDIA GeForce GT 740 > has Compute SM 3.0 ]
[h264_nvenc @ 0x559fde814240] supports NVENC

in container:

[h264_nvenc @ 0x55738218adc0] Loaded Nvenc version 11.1
[h264_nvenc @ 0x55738218adc0] Nvenc initialized successfully
[h264_nvenc @ 0x55738218adc0] 1 CUDA capable devices found
[h264_nvenc @ 0x55738218adc0] [ GPU #0 - < NVIDIA GeForce GT 740 > has Compute SM 3.0 ]
[h264_nvenc @ 0x55738218adc0] Lossless encoding not supported
[h264_nvenc @ 0x55738218adc0] No capable devices found
[h264_nvenc @ 0x55738218adc0] Nvenc unloaded

This one works in container too: ffmpeg -hide_banner -loglevel verbose -y -i /recordings/test.mp4 -c:v h264_nvenc -preset medium -pix_fmt nv12 -movflags +faststart /recordings/test1.mp4

As workaround: How i can pass "preset" or other encoder parameters to recorder output from config?

[jamitupya]

i think you can pass that via the ffmpeg component? maybe "input_args" or "hwaccel_args"?

also here as well.

[roflcoopter]

To change the codec used for the recorder you can set codec: h264_nvenc under recorder

[bsyomov]

i think you can pass that via the ffmpeg component?maybe "input_args" or "hwaccel_args"

I tried using "hwaccel_args", it adds ffmpeg argument before -i. Seems like I can use "input_args" for decoder, but not for encoder in "recorder" section. @roflcoopter May be we need somthing like "output_args" in "recorder" map?

To change the codec used for the recorder you can set codec: h264_nvenc under recorder

Yes, i can, but i need to change encoder settings, not encoder itself(switch "-c:v h264_nvenc" to "-c:v h264_nvenc -preset medium"). Now i am use SW h264 encoder as workaround, But h264_nvenc must work too, If I explicitly specify the "preset" parameter.

P.S. Sorry for my english, maybe my explanations are not clear?

[roflcoopter]

Ahh i see now what you mean. As you say a new config option is needed to support this, will get to it soon!

[roflcoopter]

When does this issue occur, is it when segments are concatenated? Or is it when the camera starts?

Trying to figure out the best way to solve this.

[bsyomov]

When segments are concatenated (and stream re-encoded in my configuration).

recorder:
        codec: h264_nvenc
        video_filters:
          - scale=1920x1080:flags=lanczos

[roflcoopter]

Implemented in dev tag now. You should be able to use this config now:

recorder:
  codec: h264_nvenc
  video_filters:
    - scale=1920x1080:flags=lanczos
  output_args:
    - -preset
    - medium