Grayscale banding in yuv420p?
I'm experimenting with ffmpeg and colorspaces.
As far as I understood, in yuv420 encodings, the chroma information is compressed, while the luma information should not.
That said, given a lossless codec, I expected a simple black to white gradient to be banding free, but it is not.
On linux the simplest experiment I did was to display a banding free gray gradient and capturing it with ffmpeg that way:
ffmpeg -f x11grab -framerate 60 -video_size 1920x1080 -i :0.0+1920,0 -pix_fmt yuv420p -f xv /dev/null
...but unfortunately what I get is this (ffmpeg on the left):
Same issue appears when I encode in x264 with yuv420p.
I wonder if this is expected and why?
ffmpeg
edited Feb 4 at 14:19
Run5k
11.3k73253
asked Feb 4 at 13:57
AntonioAntonio
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add a comment |
I'm experimenting with ffmpeg and colorspaces.
As far as I understood, in yuv420 encodings, the chroma information is compressed, while the luma information should not.
That said, given a lossless codec, I expected a simple black to white gradient to be banding free, but it is not.
On linux the simplest experiment I did was to display a banding free gray gradient and capturing it with ffmpeg that way:
ffmpeg -f x11grab -framerate 60 -video_size 1920x1080 -i :0.0+1920,0 -pix_fmt yuv420p -f xv /dev/null
...but unfortunately what I get is this (ffmpeg on the left):
Same issue appears when I encode in x264 with yuv420p.
I wonder if this is expected and why?
ffmpeg
edited Feb 4 at 14:19
Run5k
11.3k73253
asked Feb 4 at 13:57
AntonioAntonio
11
add a comment |
I'm experimenting with ffmpeg and colorspaces.
As far as I understood, in yuv420 encodings, the chroma information is compressed, while the luma information should not.
That said, given a lossless codec, I expected a simple black to white gradient to be banding free, but it is not.
On linux the simplest experiment I did was to display a banding free gray gradient and capturing it with ffmpeg that way:
ffmpeg -f x11grab -framerate 60 -video_size 1920x1080 -i :0.0+1920,0 -pix_fmt yuv420p -f xv /dev/null
...but unfortunately what I get is this (ffmpeg on the left):
Same issue appears when I encode in x264 with yuv420p.
I wonder if this is expected and why?
ffmpeg
edited Feb 4 at 14:19
Run5k
11.3k73253
asked Feb 4 at 13:57
AntonioAntonio
11
I'm experimenting with ffmpeg and colorspaces.
As far as I understood, in yuv420 encodings, the chroma information is compressed, while the luma information should not.
That said, given a lossless codec, I expected a simple black to white gradient to be banding free, but it is not.
On linux the simplest experiment I did was to display a banding free gray gradient and capturing it with ffmpeg that way:
ffmpeg -f x11grab -framerate 60 -video_size 1920x1080 -i :0.0+1920,0 -pix_fmt yuv420p -f xv /dev/null
...but unfortunately what I get is this (ffmpeg on the left):
Same issue appears when I encode in x264 with yuv420p.
I wonder if this is expected and why?
ffmpeg
ffmpeg
edited Feb 4 at 14:19
Run5k
11.3k73253
asked Feb 4 at 13:57
AntonioAntonio
11
edited Feb 4 at 14:19
Run5k
11.3k73253
asked Feb 4 at 13:57
AntonioAntonio
11
edited Feb 4 at 14:19
Run5k
11.3k73253
edited Feb 4 at 14:19
Run5k
11.3k73253
edited Feb 4 at 14:19
Run5k
11.3k73253
11.3k73253
asked Feb 4 at 13:57
AntonioAntonio
11
asked Feb 4 at 13:57
AntonioAntonio
11
asked Feb 4 at 13:57
AntonioAntonio
11
11
add a comment |
add a comment |
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