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View Full Version : x264's PSNR calculation


ramprasad85
12th January 2009, 11:36
Hi All
I am using "x264 core:65 r1065 0e1a92c"


E:\copied\std_yuv_files\vga>x264 -B 512 --dump-yuv raw_dump.yuv -o raw.264 raw.yuv 640x480 --progress
x264 : using cpu capabilities: MMX2 SSE2 SSE3 Cache64
x264 [info]: profile Main, level 3.0
x264 [info]: slice I:3 Avg QP:29.19 size: 9745 PSNR Mean Y:35.84 U:63.82 V:62.44 Avg:37.45 Global:36.84
x264 [info]: slice P:556 Avg QP:32.68 size: 2444 PSNR Mean Y:35.93 U:48.32 V:46.90 Avg:37.40 Global:37.11
x264 [info]: mb I I16..4: 55.9% 0.0% 44.1%
x264 [info]: mb P I16..4: 0.9% 0.0% 4.0% P16..4: 16.7% 5.6% 2.3% 0.0% 0.0% skip:70.5%
x264 [info]: final ratefactor: 28.31
x264 [info]: SSIM Mean Y:0.9568894
x264 [info]: PSNR Mean Y:35.933 U:48.401 V:46.983 Avg:37.397 Global:37.110 kb/s:496.67

encoded 559 frames, 2.85 fps, 496.90 kb/s

E:\copied\std_yuv_files\vga>

Using the [I]MSU Video Quality Measurement Tool v 1.52
I calculated the PSNR values. and i got
Y=43.65441
U=46.07288
V=47.19964
AVG=(47.19964+ 46.07288+ 43.65441)/3=45.64231

Please tell me Which is the correct PSNR
:thanks:

Esurnir
12th January 2009, 12:44
Y psnr is the psnr of the luminosity, U and V psnr are the psnr of the chroma information.

The average should be the correct one :)

Sagittaire
12th January 2009, 12:44
with your average qp it's x264 ... there are problem with MSU here.