[FFmpeg-user] Grayscale x264 convertion

[James Darnley]

On 2012-08-03 12:57, Andrew Gora wrote:
> Would someone advice how to convert video to grayscale?
> 
> For example, -pix_fmt gray returns:
> Incompatible pixel format 'gray' for codec 'libx264', auto-selecting format 'yuvj420p'
> 
> -pix_fmt gray16be returns:
> Incompatible pixel format 'gray16be' for codec 'libx264', auto-selecting format 'yuv444p'
> x264 [error]: high profile doesn't support 4:4:4

x264 does not have a dedicated mode for encoding a single greyscale
plane because I recall it was said to be not any more efficient than
empty chroma planes.  So with greyscale input, any colour space (pixel
format) will be greyscale.

If you want to force a colour video to become greyscale, I don't know
how you would do that using ffmpeg.