[FFmpeg-user] h264 videos are darker

Totte Karlsson totte.karlsson at alleninstitute.org
Fri Feb 14 03:08:18 EET 2020

> > ffmpeg.exe -y -vcodec rawvideo -f rawvideo -r 23 -s 658x492 -pix_fmt
> > gray -i \\.\pipe\DEV_000F315BEBB8 -c:v libx264 -crf 23
> > x:\videos\Box_1_2020T140206.avi
> What range does the input level have? mpeg or jpeg?
Each input frame is a grayscale 8bit pixel buffer with a size of 658x492. There is no compression involved before sending the data to ffmpeg, as these grayscale frames is coming from a live streaming camera.

> And which application are you using to test the "darkness" of the output file?

Right now we are just observing this by eye. It is pretty pronounced so it is easy to see.

 > As I tried to explain earlier: gray can be both, it may be better if you choose yuv420p
> / yuvj420p for encoding to make sure the right range is selected.

I tried both of those, but the resulting video is distorted with random colors flashing on the screen.

Best Regards,

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