PSNR test

root@scrocco:/mnt/m/videotest/cosmos# ll
-rw-r--r-- 1 root root 696M 14 lug  2017 cosmos_original.mp4
-rw-r--r-- 1 root root 235M 22 apr 17.44 cosmos_original_enc.mkv
-rw-r--r-- 1 root root 908M 22 apr 18.24 cosmos_q20.mp4
-rw-r--r-- 1 root root 852M 22 apr 18.24 cosmos_q21.mp4
-rw-r--r-- 1 root root 785M 22 apr 18.25 cosmos_q22.mp4
-rw-r--r-- 1 root root 707M 22 apr 18.25 cosmos_q23.mp4
-rw-r--r-- 1 root root 632M 22 apr 18.26 cosmos_q24.mp4
-rw-r--r-- 1 root root 551M 22 apr 18.27 cosmos_q25.mp4
-rw-r--r-- 1 root root 474M 22 apr 18.27 cosmos_q26.mp4
-rw-r--r-- 1 root root 435M 22 apr 18.28 cosmos_q27.mp4
-rw-r--r-- 1 root root 384M 22 apr 18.29 cosmos_q28.mp4
-rw-r--r-- 1 root root 335M 22 apr 18.29 cosmos_q29.mp4
-rw-r--r-- 1 root root 294M 22 apr 18.30 cosmos_q30.mp4
-rw-r--r-- 1 root root 258M 23 apr 02.47 cosmos_q31.mp4
-rw-r--r-- 1 root root 219M 23 apr 02.47 cosmos_q32.mp4
-rw-r--r-- 1 root root 191M 23 apr 02.48 cosmos_q33.mp4
-rw-r--r-- 1 root root 162M 23 apr 02.49 cosmos_q34.mp4
-rw-r--r-- 1 root root 141M 23 apr 02.49 cosmos_q35.mp4
-rw-r--r-- 1 root root 123M 23 apr 02.50 cosmos_q36.mp4
-rw-r--r-- 1 root root 109M 23 apr 02.50 cosmos_q37.mp4
-rw-r--r-- 1 root root  96M 23 apr 02.51 cosmos_q38.mp4
-rw-r--r-- 1 root root  86M 23 apr 02.52 cosmos_q39.mp4
-rw-r--r-- 1 root root  79M 23 apr 02.52 cosmos_q40.mp4

root@scrocco:/mnt/m/videotest/cosmos# for f in *; do echo "=== $f ==="; ffmpeg -i cosmos_original.mp4 -i "$f" -lavfi "[0:v][1:v]ssim" -f null - 2>&1 | grep SSIM; done

=== cosmos_original.mp4 ===
[Parsed_ssim_0 @ 0x7f7988003000] SSIM Y:1.000000 (inf) U:1.000000 (inf) V:1.000000 (inf) All:1.000000 (inf)
=== cosmos_original_enc.mkv ===
[Parsed_ssim_0 @ 0x7f8914003000] SSIM Y:0.909983 (10.456769) U:0.975370 (16.085423) V:0.983960 (17.948087) All:0.933211 (11.752930)
=== cosmos_q20.mp4 ===
[Parsed_ssim_0 @ 0x7f4b54003000] SSIM Y:0.986714 (18.765895) U:0.994442 (22.550632) V:0.994441 (22.550338) All:0.989290 (19.701913)
=== cosmos_q21.mp4 ===
[Parsed_ssim_0 @ 0x7f9ce8003000] SSIM Y:0.986194 (18.599241) U:0.994187 (22.356007) V:0.994084 (22.279976) All:0.988841 (19.523770)
=== cosmos_q22.mp4 ===
[Parsed_ssim_0 @ 0x7fa718003000] SSIM Y:0.985249 (18.311863) U:0.993800 (22.076152) V:0.993639 (21.964406) All:0.988073 (19.234545)
=== cosmos_q23.mp4 ===
[Parsed_ssim_0 @ 0x7faa6c003000] SSIM Y:0.983947 (17.944417) U:0.993358 (21.777216) V:0.993067 (21.591036) All:0.987036 (18.872465)
=== cosmos_q24.mp4 ===
[Parsed_ssim_0 @ 0x7f6e94003000] SSIM Y:0.982489 (17.566809) U:0.992959 (21.523942) V:0.992649 (21.336412) All:0.985927 (18.516181)
=== cosmos_q25.mp4 ===
[Parsed_ssim_0 @ 0x7f0de0003000] SSIM Y:0.980325 (17.060867) U:0.992455 (21.223397) V:0.991859 (20.893404) All:0.984269 (18.032463)
=== cosmos_q26.mp4 ===
[Parsed_ssim_0 @ 0x7fa938003000] SSIM Y:0.977907 (16.557448) U:0.991881 (20.904714) V:0.991198 (20.554324) All:0.982451 (17.557505)
=== cosmos_q27.mp4 ===
[Parsed_ssim_0 @ 0x7f05b4003000] SSIM Y:0.976519 (16.292802) U:0.991600 (20.757389) V:0.990894 (20.406564) All:0.981428 (17.311465)
=== cosmos_q28.mp4 ===
[Parsed_ssim_0 @ 0x7f04c0003000] SSIM Y:0.974336 (15.906675) U:0.991125 (20.518110) V:0.990395 (20.175064) All:0.979810 (16.948699)
=== cosmos_q29.mp4 ===
[Parsed_ssim_0 @ 0x7fbfec003000] SSIM Y:0.971606 (15.467729) U:0.990463 (20.205874) V:0.989738 (19.887695) All:0.977771 (16.530764)
=== cosmos_q30.mp4 ===
[Parsed_ssim_0 @ 0x7f129c003000] SSIM Y:0.969048 (15.093079) U:0.989826 (19.925256) V:0.989157 (19.648639) All:0.975862 (16.173071)
=== cosmos_q31.mp4 ===
[Parsed_ssim_0 @ 0x7f05b0003000] SSIM Y:0.966596 (14.761973) U:0.989238 (19.680905) V:0.988627 (19.441136) All:0.974041 (15.857148)
=== cosmos_q32.mp4 ===
[Parsed_ssim_0 @ 0x7f0dac003000] SSIM Y:0.963031 (14.321582) U:0.988203 (19.282148) V:0.987770 (19.125740) All:0.971349 (15.428634)
=== cosmos_q33.mp4 ===
[Parsed_ssim_0 @ 0x7fe628003000] SSIM Y:0.959769 (13.954380) U:0.987181 (18.921419) V:0.987033 (18.871705) All:0.968882 (15.069831)
=== cosmos_q34.mp4 ===
[Parsed_ssim_0 @ 0x7f9720003000] SSIM Y:0.955855 (13.551186) U:0.985979 (18.532272) V:0.986138 (18.581661) All:0.965923 (14.675365)
=== cosmos_q35.mp4 ===
[Parsed_ssim_0 @ 0x7f7914003000] SSIM Y:0.952006 (13.188154) U:0.984802 (18.182069) V:0.985328 (18.335167) All:0.963026 (14.321016)
=== cosmos_q36.mp4 ===
[Parsed_ssim_0 @ 0x7efe98003000] SSIM Y:0.947816 (12.824624) U:0.983244 (17.758263) V:0.984254 (18.028372) All:0.959794 (13.957056)
=== cosmos_q37.mp4 ===
[Parsed_ssim_0 @ 0x7feeb0003000] SSIM Y:0.943497 (12.479265) U:0.981644 (17.362186) V:0.983315 (17.776791) All:0.956491 (13.614209)
=== cosmos_q38.mp4 ===
[Parsed_ssim_0 @ 0x7f8e2c003000] SSIM Y:0.938106 (12.083483) U:0.979429 (16.867419) V:0.982224 (17.501540) All:0.952346 (13.218985)
=== cosmos_q39.mp4 ===
[Parsed_ssim_0 @ 0x7f0d30003000] SSIM Y:0.933128 (11.747546) U:0.977545 (16.486932) V:0.981267 (17.273833) All:0.948554 (12.886473)
=== cosmos_q40.mp4 ===
[Parsed_ssim_0 @ 0x7f64d8003000] SSIM Y:0.927914 (11.421500) U:0.975647 (16.134483) V:0.980266 (17.047946) All:0.944595 (12.564512)