Encoding-Quality-Testing

Created with the vmaf-docker repo.

Reference content

Reference content is either our own (https://media.ccc.de) or from Xiph (https://media.xiph.org/video/derf/).

The specific sources are found in https://github.com/voc/vmaf-docker/blob/master/data/sources.json

All the reference content is converted to 8bit 1080p25.

Software

ffmpeg-4.1.4 (same as in buster)

libvmaf-1.3.15

libvpx-1.8.2 (bullseye)

libx264-2:0.155.2917+git0a84d98-2 (bullseye)

Testing VAAPI vs. software encoding for live streaming

The codec settings are the ones currently in use by the C3VOC for live streaming.

See https://github.com/voc/vmaf-docker/blob/master/data/libquality/profiles/voc_streaming.py for the specific ffmpeg options.

The codecs are tested with bitrates from 1Mbit/s to 5.2Mbit/s.

Graphs

streaming_rates.pdf streaming_refs.pdf streaming_speeds.pdf

Comments

Platform	Label	Hardware Codecs	Comments
Intel 6th Gen (i7-6600U)	skylake	h.264, h.265	h.264 scores better than our VP9 and x264 streaming settings and is pretty fast h.265 even scores a little bit higher but is considerably slower
Intel 8th Gen (i7-8665U)	whiskeylake	h.264, h.265, VP9	h.264 and h.265 results are identical to skylake VP9 scores worse than H.264 and has broken rate-control for <2mbit/s
AMD Navi (RX 5700 XT) + Ryzen 2nd Gen (R5-2600)	navi10	h.264, h.265	h.264 is worse than x264 on veryfast… h.265 produces 1920×1088 output?