compare quality of h264 streams encoded by x264

[msm_007]

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]

Personaly, I compare with my eyes.

[LoRd_MuldeR]

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]

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]

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 ;)

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]

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