[FFmpeg-user] The internal ffmpeg rgb=>yuv pipeline and conversion matrices

[Peter Rabbitson]

On 05/09/2016 04:34 PM, Andy Furniss wrote:
>
> Don't test with color src - use something real and you  may see different.
>

Nod.

For completeness below is *literally* what my pipeline looks like, 
except of course it isn't "all green". The command as-is produces 
satisfactory results for both the HD and the SD part.


perl -e '
   die "Need dimensions" if grep { $_ !~ /^\d+$/ } @ARGV[0,1];

   my $ppm_frame =
     "P6\n$ARGV[0] $ARGV[1]\n255\n"
   . pack('C3', 0, 0xAA, 0 ) x ($ARGV[0] * $ARGV[1])
   ;

   print $ppm_frame while 1;
' \
1280 \
720 \
| ffmpeg  -y -hide_banner \
           -r 30 -probesize 32M -f image2pipe -c:v ppm -i /dev/stdin \
           -filter_complex '
   [0]
     scale=out_color_matrix=bt709:out_range=tv,
     split [sd];

   [sd]
     scale=320x240
   ' \
           -c:v libx264 -colorspace bt709 -pix_fmt yuv444p -profile:v 
high444 \
           -qp 0 -preset:v ultrafast \
           -t 5 greenz.mkv