how to record video without lags

[tom2374]

I have a weak computer and when I record video using ffmpeg or OBS they use 80 percent of the processor, so everything freezes when recording. Is there a lightweight utility or a way to not lose performance so much?
my start ffmpeg

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ffmpeg -video_size 1920x1080 -framerate 25 -f x11grab -i :0.0+0,0 probnik.mp4

[NeddySeagoon]

tom2374,

Its the compression that takes all the CPU cycles.
Grab the video first. WIthout compression. That will be big. Compress it later when you don't mind that it uses all the resources.

If you must do it all in one, try to nice the ffmpeg process.
However, depending on what else is going on, that can lead to dropped frames in the recording.

[tom2374]

sorry for being stupid, but how do I record a video without compression? I tried this

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ffmpeg -framerate 60 -f x11grab -i :0.0+0,0 probnik.mp4

but it didn't help, could you give me a specific command to record without compression?

[b11n]

try adding

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-vcodec rawvideo -pix_fmt rgb32

before the output filename (but after the '-i'). Alternatively, if your "weak" computer at least has a capable GPU, even a 10 year old one, encoding could be offloaded to it to free up CPU

[tom2374]

i try

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ffmpeg -framerate 60 -f x11grab -i :0.0+0,0 -vcodec rawvideo -pix_fmt rgb32 probnik.mp4

but get this

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[x11grab @ 0x5580a89fb600] Stream #0: not enough frames to estimate rate; consider increasing probesize
Input #0, x11grab, from ':0.0+0,0':
  Duration: N/A, start: 1748918166.759938, bitrate: 3981312 kb/s
  Stream #0:0: Video: rawvideo (BGR[0] / 0x524742), bgr0, 1920x1080, 3981312 kb/s, 60 fps, 1000k tbr, 1000k tbn
File 'probnik.mp4' already exists. Overwrite? [y/N] y
Stream mapping:
  Stream #0:0 -> #0:0 (rawvideo (native) -> rawvideo (native))
Press [q] to stop, [?] for help
[mp4 @ 0x5580a8a04880] Could not find tag for codec rawvideo in stream #0, codec not currently supported in container
[out#0/mp4 @ 0x5580a8a04780] Could not write header (incorrect codec parameters ?): Invalid argument
[vf#0:0 @ 0x5580a8a05580] Error sending frames to consumers: Invalid argument
[vf#0:0 @ 0x5580a8a05580] Task finished with error code: -22 (Invalid argument)
[vf#0:0 @ 0x5580a8a05580] Terminating thread with return code -22 (Invalid argument)
[out#0/mp4 @ 0x5580a8a04780] Nothing was written into output file, because at least one of its streams received no packets.

[b11n]

ah yes, you'll also need to use

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-f rawvideo

and drop the .mp4 suffix, as the MP4 container can't handle raw RGB frames