Hi Ben, great challenge that you have arranged!
Here are encodes with the xvc codec at three different rates:
There is no strict rate control in xvc yet so the margins to the target rates are quite large.
851 kbps:
https://drive.google.com/file/d/1xrM...ew?usp=sharing (15% under target rate)
1361 kbps:
https://drive.google.com/file/d/1cRs...ew?usp=sharing (9% under target rate)
1924 kbps:
https://drive.google.com/file/d/1K46...ew?usp=sharing (4% under target rate)
To play the files you need a player with xvc support such as this build of ffplay:
https://drive.google.com/file/d/1gyj...ew?usp=sharing
The zip file also contains the build of ffmpeg that was used to encode the files using the following command:
ffmpeg.exe -i d:/ToS_1920x800_xdither.y4m -c:v libxvc -speed-mode 2 -qp X -max-keypic-distance 120 -threads 16 enc.mp4
with X being 28, 25 and 23, respectively.
It can be noted that these encodes are single pass, with no lookahead (beyond the 16 picture sub-GOP structure), and that reference pictures are stored with 10-bit precision internally (there is no 8 bit profile of xvc).
I would be happy to hear what people think of it! Thanks!