Optimal parameters for VP8/9 encoder for every stream level (low, mid, hi) #7
Description
Need to find optimal encoder parameters in terms of maximum/target bandwidth and framerate for three levels of video quality: low, medium and high. Latest encoder unit tests show higher actual bandwidth for 720p than requested:
[ RUN ] TestCoder.TestEncode700K
[ INFO ] 5 frames encoding took 100 ms (avg 20.00 ms per frame)
[ INFO ] Encoded 30 (1280x720) frames with target rate 700 Kbit/s: encoded 5 frames, dropped 25 frames, actual rate 1155 Kbit/s, 1 key, 4 delta
[ INFO ] Encoded frame sizes (bytes): key - 29384.00, delta - 28393.00
[ OK ] TestCoder.TestEncode700K (1357 ms)
[ RUN ] TestCoder.TestEncode1000K
[ INFO ] 7 frames encoding took 139 ms (avg 19.86 ms per frame)
[ INFO ] Encoded 30 (1280x720) frames with target rate 1000 Kbit/s: encoded 7 frames, dropped 23 frames, actual rate 1606 Kbit/s, 1 key, 6 delta
[ INFO ] Encoded frame sizes (bytes): key - 29376.00, delta - 28378.83
[ OK ] TestCoder.TestEncode1000K (1349 ms)
[ RUN ] TestCoder.TestEncode2000K
[ INFO ] 11 frames encoding took 213 ms (avg 19.36 ms per frame)
[ INFO ] Encoded 30 (1280x720) frames with target rate 2000 Kbit/s: encoded 11 frames, dropped 19 frames, actual rate 2917 Kbit/s, 1 key, 10 delta
[ INFO ] Encoded frame sizes (bytes): key - 75784.00, delta - 28305.40
[ OK ] TestCoder.TestEncode2000K (1335 ms)
[ RUN ] TestCoder.TestEncode3000K
[ INFO ] 16 frames encoding took 304 ms (avg 19.00 ms per frame)
[ INFO ] Encoded 30 (1280x720) frames with target rate 3000 Kbit/s: encoded 16 frames, dropped 14 frames, actual rate 4325 Kbit/s, 1 key, 15 delta
[ INFO ] Encoded frame sizes (bytes): key - 109829.00, delta - 28218.53
[ OK ] TestCoder.TestEncode3000K (1339 ms)
[ RUN ] TestCoder.TestEnforceNoDrop
[ INFO ] 30 frames encoding took 920 ms (avg 30.67 ms per frame)
[ INFO ] Encoded 30 (1920x1080) frames with target rate 1000 Kbit/s: encoded 30 frames, dropped 0 frames, actual rate 16223 Kbit/s, 1 key, 29 delta
[ INFO ] Encoded frame sizes (bytes): key - 66965.00, delta - 64891.14
[ OK ] TestCoder.TestEnforceNoDrop (1562 ms)
[ RUN ] TestCoder.TestEnforceKeyGop
[ INFO ] 90 frames encoding took 1748 ms (avg 19.42 ms per frame)
[ INFO ] Encoded 90 (1280x720) frames with target rate 10000 Kbit/s: encoded 90 frames, dropped 0 frames, actual rate 9937 Kbit/s, 3 key, 87 delta
[ INFO ] Encoded frame sizes (bytes): key - 194611.33, delta - 35067.60
[ OK ] TestCoder.TestEnforceKeyGop (4044 ms)
[ RUN ] TestCoder.TestEnforceKeyTimed
[ INFO ] 36 frames encoding took 732 ms (avg 20.33 ms per frame)
[ INFO ] Encoded 90 (1280x720) frames with target rate 3000 Kbit/s: encoded 36 frames, dropped 54 frames, actual rate 3442 Kbit/s, 3 key, 33 delta
[ INFO ] Encoded frame sizes (bytes): key - 117339.67, delta - 28202.61
[ OK ] TestCoder.TestEnforceKeyTimed (4096 ms)
[----------] 10 tests from TestCoder (16478 ms total)
As can be seen from the test, 720p@30fps requires much higher bandwidth than expected:
[ RUN ] TestCoder.TestEnforceKeyGop
[ INFO ] 90 frames encoding took 1748 ms (avg 19.42 ms per frame)
[ INFO ] Encoded 90 (1280x720) frames with target rate 10000 Kbit/s: encoded 90 frames, dropped 0 frames, actual rate 9937 Kbit/s, 3 key, 87 delta
[ INFO ] Encoded frame sizes (bytes): key - 194611.33, delta - 35067.60
[ OK ] TestCoder.TestEnforceKeyGop (4044 ms)