[FFmpeg-devel] [PATCH] Extract QP from h264 encoded videos

[Juan De León]

Previous thread:
http://ffmpeg.org/pipermail/ffmpeg-devel/2019-July/246951.html
I added the modifications to the decoder, I ran some tests for performance
and run times are only affected if my flag is enabled.
Decoded 3 different encoded videos 20 times each with and without my debug
flag, here are the results:

*ExtractQP disabled:*
===> multitime results
1: ffmpeg -hide_banner -loglevel panic -debug 0 -i tveryfast.mp4 -f null -
            Mean        Std.Dev.    Min         Median      Max
real        0.747       0.007       0.735       0.749       0.756
user        5.582       0.025       5.547       5.574       5.627
sys         0.166       0.028       0.120       0.167       0.224
===> multitime results
1: ffmpeg -hide_banner -loglevel panic -debug 0 -i tmedium.mp4 -f null -
            Mean        Std.Dev.    Min         Median      Max
real        0.865       0.009       0.845       0.864       0.887
user        6.296       0.036       6.198       6.299       6.365
sys         0.195       0.026       0.142       0.199       0.247
===> multitime results
1: ffmpeg -hide_banner -loglevel panic -debug 0 -i tveryslow.mp4 -f null -
            Mean        Std.Dev.    Min         Median      Max
real        0.919       0.011       0.892       0.920       0.943
user        6.398       0.042       6.311       6.381       6.476
sys         0.229       0.032       0.169       0.238       0.287

*ExtractQP enabled: *
===> multitime results
1: ffmpeg -hide_banner -loglevel panic -debug extractqp -i tveryfast.mp4 -f
null -
            Mean        Std.Dev.    Min         Median      Max
real        1.126       0.032       1.076       1.132       1.216
user        6.433       0.054       6.347       6.430       6.561
sys         1.069       0.047       0.989       1.063       1.161
===> multitime results
1: ffmpeg -hide_banner -loglevel panic -debug extractqp -i tmedium.mp4 -f
null -
            Mean        Std.Dev.    Min         Median      Max
real        1.178       0.020       1.143       1.176       1.217
user        7.091       0.055       7.020       7.081       7.196
sys         1.031       0.057       0.898       1.043       1.131
===> multitime results
1: ffmpeg -hide_banner -loglevel panic -debug extractqp -i tveryslow.mp4 -f
null -
            Mean        Std.Dev.    Min         Median      Max
real        1.234       0.028       1.196       1.230       1.322
user        7.212       0.077       6.996       7.230       7.345
sys         1.067       0.076       0.938       1.062       1.283