dimakl
30th June 2009, 15:55
Hello.
I'm working with x264 encoder, and try to run different tests and study various quality metrics behavior.
I tried to learn the correlation between bitrate and MOS (for example) when x264 activated with fixed QP, i.e. rate-controller is disabled.
Please help me to analyze the log-file that x264 built.
Here are few lines from the log:
x264 [info]: 352x240 @ 25.00 fps
x264 [info]: using cpu capabilities: MMX2 SSE2 SSE3 Cache64
x264 [info]: profile Main, level 4.0
x264 [debug]: frame= 0 QP=25.00 NAL=3 Slice:I Poc:0 I:330 P:0 SKIP:0 size=13912 bytes PSNR Y:40.35 U:46.49 V:44.37 SSIM Y:0.98723
x264 [debug]: frame= 1 QP=25.00 NAL=2 Slice:P Poc:2 I:0 P:232 SKIP:98 size=2776 bytes PSNR Y:39.24 U:46.51 V:43.58 SSIM Y:0.98626
.
.
x264 [info]: slice I:3 Avg QP:25.00 size: 15196 PSNR Mean Y:39.80 U:46.81 V:44.38 Avg:41.00 Global:40.98
x264 [info]: slice P:528 Avg QP:25.00 size: 3340 PSNR Mean Y:38.72 U:45.94 V:43.10 Avg:39.92 Global:39.89
x264 [info]: mb I I16..4: 5.8% 0.0% 94.2%
x264 [info]: mb P I16..4: 0.1% 0.0% 0.2% P16..4: 43.2% 21.8% 18.7% 0.0% 0.0% skip:16.0%
x264 [info]: SSIM Mean Y:0.9836728
x264 [info]: PSNR Mean Y:38.730 U:45.944 V:43.109 Avg:39.923 Global:39.895 kb/s:681.44
encoded 531 frames, 28.14 fps, 681.64 kb/s
For example, I get the compressed file with size 532,512 bytes with 531 frames (@25fps)
So, I expect to get bitrate = 25 kbytes per sec
Really, if I count the "size" value taken from each line (slice) - I get relevant value.
In the other hand,
According the log file, I see quite different numbers in the last line of average statistics
So, my question is:
How should I read the last line in the log-file?
How can I see the bitrate? is it printed in bits per sec? bytes per sec?
Thank you.
I'm working with x264 encoder, and try to run different tests and study various quality metrics behavior.
I tried to learn the correlation between bitrate and MOS (for example) when x264 activated with fixed QP, i.e. rate-controller is disabled.
Please help me to analyze the log-file that x264 built.
Here are few lines from the log:
x264 [info]: 352x240 @ 25.00 fps
x264 [info]: using cpu capabilities: MMX2 SSE2 SSE3 Cache64
x264 [info]: profile Main, level 4.0
x264 [debug]: frame= 0 QP=25.00 NAL=3 Slice:I Poc:0 I:330 P:0 SKIP:0 size=13912 bytes PSNR Y:40.35 U:46.49 V:44.37 SSIM Y:0.98723
x264 [debug]: frame= 1 QP=25.00 NAL=2 Slice:P Poc:2 I:0 P:232 SKIP:98 size=2776 bytes PSNR Y:39.24 U:46.51 V:43.58 SSIM Y:0.98626
.
.
x264 [info]: slice I:3 Avg QP:25.00 size: 15196 PSNR Mean Y:39.80 U:46.81 V:44.38 Avg:41.00 Global:40.98
x264 [info]: slice P:528 Avg QP:25.00 size: 3340 PSNR Mean Y:38.72 U:45.94 V:43.10 Avg:39.92 Global:39.89
x264 [info]: mb I I16..4: 5.8% 0.0% 94.2%
x264 [info]: mb P I16..4: 0.1% 0.0% 0.2% P16..4: 43.2% 21.8% 18.7% 0.0% 0.0% skip:16.0%
x264 [info]: SSIM Mean Y:0.9836728
x264 [info]: PSNR Mean Y:38.730 U:45.944 V:43.109 Avg:39.923 Global:39.895 kb/s:681.44
encoded 531 frames, 28.14 fps, 681.64 kb/s
For example, I get the compressed file with size 532,512 bytes with 531 frames (@25fps)
So, I expect to get bitrate = 25 kbytes per sec
Really, if I count the "size" value taken from each line (slice) - I get relevant value.
In the other hand,
According the log file, I see quite different numbers in the last line of average statistics
So, my question is:
How should I read the last line in the log-file?
How can I see the bitrate? is it printed in bits per sec? bytes per sec?
Thank you.