AV1 vs VP9 vs AVC (h.264) vs HEVC (h.265): Part I - Lossless

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Conclusion

  • In terms of lossless compression, x264 and x265 took less time and produced smaller files. All video codecs produced smaller video files than LZMA/LZMA2, the general purpose compression algorithms.
  • In our tests, AV1 takes approximately 160-190x more time than x264 to encode in their lossless mode. AV1 does have a lossless mode, but the output is not lossless at all.
  • VP9 and AV1 can take advantage of multi-threading, but they can not load all CPU cores all the time as x264 and x265 do.

Note

  • At of June 2018, AV1 is still experimental.
  • We used x264 as the AVC encoder.
  • We used x265 as the HEVC encoder.
  • We used pxz as the LZMA/LZMA2 compressor. LZMA is also the default algorithm of 7-Zip.
  • The AV1 encoder ran with "--cpu-used=4" for "medium" speed, "--tile-columns=4" to enabling multi-threading. All encoders ran in their lossless mode, all other settings were as default.

Test 1

Source video


sintel_trailer_2k_480p24.y4m
© copyright Blender Foundation | durian.blender.org.
downloaded from https://xiph-media.net/

Results

File size vs source Real time vs x264 CPU time vs x264
source 770,452,201 100% / / / /
x264 64,472,680 8.37% 8.952s 1:1 31.355s 1:1
x265 73,248,027 9.51% 45.912s 5.13:1 2m40.161s 5.11:1
VP9 81,054,127 10.52% 1m51.466s 12.45:1 3m19.448s 6.36:1
AV1[1] 89,369,111 11.60% 24m34.523s 164.71:1 70m58.562s 135.82:1
pxz 96,012,992 12.46% 1m26.648s 9.68:1 4m04.300s 7.79:1
  1. Though encoded in the lossless mode, the result of AV1 is not lossless. If it is lossless, PSNR should be "inf" (infinity). 
    SSIM Y:1.000000 (73.043867) U:1.000000 (70.134668) V:1.000000 (69.880162) All:1.000000 (72.541141)
PSNR y:97.786557 u:99.494677 v:99.335577 average:98.264431 min:79.206295 max:inf
    Encoding using only single thread gives better quality but the result is still not lossless.

Test 2

Source video


First 1000 frames of big_buck_bunny_360p24.y4m
(c) copyright 2008, Blender Foundation / www.bigbuckbunny.org.
downloaded from https://xiph-media.net/

Results

File size vs source Real time vs x264 CPU time vs x264
source 345,606,058 100% / / / /
x264 78,792,519 22.80% 5.988s 1:1 21.682s 1:1
x265 70,727,042 20.46% 36.840s 6.15:1 1m59.747s 5.52:1
VP9 85,613,755 24.77% 1m15.534s 12.61:1 2m20.185s 6.47:1
AV1[1] 118,300,962 34.23% 19m21.654s 194.00:1 60m12.302s 166.60:1
pxz 124,903,768 36.14% 1m05.077s 10.87:1 3m13.756s 8.94:1
  1. Though encoded in the lossless mode, the result of AV1 is not lossless. If it is lossless, PSNR should be "inf" (infinity). 
    SSIM Y:1.000000 (68.378644) U:1.000000 (68.364410) V:1.000000 (67.624717) All:1.000000 (68.654537)
PSNR y:95.817232 u:97.454878 v:97.277848 average:96.274602 min:77.131648 max:inf
    Encoding using only single thread gives better quality but the result is still not lossless.

Commands

Encode

AV1: aomenc --lossless=1 --cpu-used=4 --tile-columns=4 --webm -o output source
     ffmpeg -i av1.webm -c copy av1.mkv # Time of this part wasn't counted.
VP9: ffmpeg -i source -c:v libvpx-vp9 -lossless 1 output.mkv
x264: ffmpeg -i source -c:v libx264 -qp 0 output.mkv
x265: ffmpeg -i source -c:v libx265 -x265-params lossless=1 output.mkv
lzma: pxz -k source

Get the first 1000 frames:

ffmpeg -i source -vframes 1000 -f yuv4mpegpipe output

Calculate PSNR and SSIM

ffmpeg -i encoded-video -f yuv4mpegpipe output
ffmpeg -i output -i source -lavfi "ssim;[0:v][1:v]psnr" -f null -

Codec version

AV1: aomenc 1.0.0-21-g96ee0eb45, source files downloaded from https://aomedia.googlesource.com/aom, Jun 28 2018
VP9: LAVC (h264)58.20.104 libvpx-vp9, source files downloaded from https://chromium.googlesource.com/webm/libvpx.git, Jun 28 2018
x264: core 155, source files downloaded from http://git.videolan.org/git/x264, Jun 28 2018
x265: 2.8+24-289b8a3730ae:[Linux][GCC 8.0.1][64 bit] 8bit, source file downloaded from https://bitbucket.org/multicoreware/x265, Jun 28 2018
ffmpeg: N-91378-g3f95337, source files downloaded from https://ffmpeg.org/releases/ffmpeg-snapshot.tar.bz2, Jun 28 2018
LZMA: Parallel PXZ 4.999.9beta (build 20180209), Fedora 28
      liblzma: 5.2.3, Fedora 28

Environment

  • OS: GNU/Linux (Fedora 28)
  • CPU: Intel Core i5 @ 4.0GHz

Related

Comments

  1. locNovember 18, 2018 at 4:32 PM

    If you try adding `-preset veryfast` to your x264 lossless command you a big speedup with only a small penalty in size.

    ReplyDelete

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