compare quality of h264 streams encoded by x264

msm_007 · 11th October 2009, 19:41

Hi all,
plz how can we compare quality of 2 h264 streams encoded by x264 for the same input but with different configuration of x264

MatLz · 11th October 2009, 19:45

Personaly, I compare with my eyes.

LoRd_MuldeR · 11th October 2009, 19:49

With x264's Psy-optimizations enabled (and they are enabled by default), you can only use your eyes for comparison

If you want to compare PSNR or SSIM, you should use "--tune psnr" or "--tune ssim", otherwise the results will be misleading...

msm_007 · 11th October 2009, 20:53

you have reason; eyes are the best way to compare quality
but always there are some details cannot be seen by eyes specially when the encoding time and the size of each streams are different

plz how can we use psnr or ssim to compare quality, I've used them but I've didn't manage to compare quality of streams

thx for your help, MSM

LoRd_MuldeR · 11th October 2009, 21:01

Quote:

Originally Posted by msm_007

you have reason; eyes are the best way to compare quality
but always there are some details cannot be seen by eyes specially when the encoding time and the size of each streams are different

1. Detail that cannot be seen by the human eye is irrelevant, isn't it? ^^

2. The encoding time is irrelevant for a visual comparison. Of course we expect a stream encoded with "slower" settings to look better, but that's it.

3. Because we cannot visually compare streams of different size, we use 2-Pass mode and compare streams of identical size

Quote:

Originally Posted by msm_007

plz how can we use psnr or ssim to compare quality, I've used them but I've didn't manage to compare quality of streams

x264.exe --psnr --tune psnr [your settings here]

x264.exe --ssim --tune ssim [your settings here]

dstln · 12th October 2009, 23:50

You can use a compare script in avsp, for example.

11th October 2009, 19:41	#1 \| Link
msm_007 Registered User Join Date: Jan 2009 Posts: 34	compare quality of h264 streams encoded by x264 Hi all, plz how can we compare quality of 2 h264 streams encoded by x264 for the same input but with different configuration of x264

11th October 2009, 19:45	#2 \| Link
MatLz I often say "maybe"... Join Date: Jul 2009 Location: France Posts: 583	Personaly, I compare with my eyes. __________________ We are spitting food to these hungry eyes. You see they ask, we know they are greedy of our rot. Better than to give jam to pigs. x264 r2146 MOD

11th October 2009, 19:49	#3 \| Link
LoRd_MuldeR Software Developer Join Date: Jun 2005 Location: Last House on Slunk Street Posts: 13,248	With x264's Psy-optimizations enabled (and they are enabled by default), you can only use your eyes for comparison If you want to compare PSNR or SSIM, you should use "--tune psnr" or "--tune ssim", otherwise the results will be misleading... __________________ Go to https://standforukraine.com/ to find legitimate Ukrainian Charities 🇺🇦✊

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11th October 2009, 20:53	#4 \| Link
msm_007 Registered User Join Date: Jan 2009 Posts: 34	you have reason; eyes are the best way to compare quality but always there are some details cannot be seen by eyes specially when the encoding time and the size of each streams are different plz how can we use psnr or ssim to compare quality, I've used them but I've didn't manage to compare quality of streams thx for your help, MSM

12th October 2009, 23:50	#6 \| Link
dstln Person Join Date: Jul 2009 Posts: 58	You can use a compare script in avsp, for example.