[x265] Fwd: coding efficieny comparision between and HM

[idxa at sina.com]

Hi, I have done more tests about x265 using the encoding options described in previous mail. Tested video clips include C class of HEVC official test sequences(832x480) and 3 private video clips(640x360). Test result shows that PSNR of HM is higher than x265(at least 0.3db, worst about 0.85db) at about same bitrate. It seems that the difference of PNSR depends on complexity of video content. The last video clip is very especial.When encoding this video PSNR of x265 is less than x264, and also is about 0.85db less than HM11. I think it is useful if including this video clip into your test sequences. 
 
Command line:
X265
x265.exe --input source\RaceHorses_832x480_30.yuv –o output\RaceHorses_832x480_30_x265.hevc --recon output\RaceHorses_832x480_30_x265_recon.yuv --fps 30 --input-res 832x480 --qp 34 -F 4 --bframes 0 --b-adapt 0  --keyint 300 --log 3
 
x264
x264.exe --preset veryslow --no-mbtree --tune psnr --qp 37 --input-res 832x480 --dump-yuv RaceHorses_832x480_30_x264_recon.yuv -o RaceHorse_832x480_30_x264.264 source\RaceHorses_832x480_30.yuv --bframes 0 --fps 30 --ref 1 --keyint 300 --verbose
 
HM11.0
HM cfg file is modified (see previous mail) to guarantee that all frames are using a same QP, constant lambda, 1 ref and so on. The target is to make the encoding parameters of HM being similar to x265.
 
Here, the parameters are adjusted according to video resolution, fps and number of frames to be encoded, etc. And In x265 and x264, “--qp” value is adjusted to get same size of output file of these 3 encoders. 
 
 
Test Results
First 4 clips are official test sequences.
RaceHorses(832x480, 30fps)




 

Bitrate(kb/s)

PSNR


HM11.0

845.6

31.604


x265

868.8

31.242


x264

884.0

30.866
 
BasketballDrill(832x480, 50fps)




 

Bitrate(kb/s)

PSNR


HM11.0

788.0

32.714


x265

823.2

32.354


x264

844.8

31.587
 
PartyScene(832x480, 50fps)




 

Bitrate(kb/s)

PSNR


HM11.0

1726.4

29.504


x265

1680.0

28.962


x264

1736.8

28.462
 
BQMall(832x480, 60fps)




 

Bitrate(kb/s)

PSNR


HM11.0

883.2

33.132


x265

917.6

32.606


x264

928.0

32.059
 
The following 3 clips are private test sequences.
NBA(640x360, 30fps)




 

Bitrate(kb/s)

PSNR


HM11.0

576.0

29.644


x265

584.8

29.355


x264

593.6

28.929
 
 
Party_1(640x360, 25fps)




 

Bitrate(kb/s)

PSNR


HM11.0

602.4

31.840


x265

637.6

31.542


x264

622.4

31.103
 
Party_2(640x360, 25fps)




 

Bitrate(kb/s)

PSNR


HM11.0

1260.8

30.999


x265

1269.6

30.150


x264

1296.8

30.268
 
 
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