4th i7 better than 6th i5 in h.264 encoding?

[高__超]

Hi,

I have used sample_encode in Intel Media SDK Samples 2016 6.0.0.142 to convert video from YUV420p to h.264, and used Evalvid to calculate PSNR  and SSIM.

I have found that PSNR and SSIM performed better in i7-4702mq than i3-4160 and i5-6400.

The enviroment is : 

i7-4702mq + 4G DDR3 1600MHz * 2 + Win 8.1 x64

i3-4160 + 2G DDR3 1600MHz * 2 + Win7 x64

i5-6400 + 8G DDR4 2133MHz * 2 + Win7 x64

The command line is :

sample_encode h264 -w 1920 -h 1080 -f 24 -b 1000 -i input.yuv -o output.264 -hw

I have run the encoding program in the same command line, and changed the resolution and bitrate as follow.

500kbps 1000kbps 2000kbps in 720p

1000kbps 2000kpbs 4000kbps in 1080p

The result is :

video	resolution	bitrate	PSNR			SSIM
			i3-4160	i7-4702m	i5-6400	i3-4160	i7-4702m	i5-6400
afd	1080	1000	37.198	38.208	37.237	0.919	0.925	0.919
		2000	40.676	41.506	40.715	0.951	0.956	0.950
		4000	43.449	44.200	43.514	0.970	0.973	0.970
	720	500	36.185	37.014	36.156	0.898	0.905	0.897
		1000	39.435	40.246	39.500	0.937	0.942	0.937
		2000	42.312	43.096	42.299	0.962	0.966	0.962
ring	1080	1000	38.820	40.273	38.675	0.937	0.944	0.938
		2000	44.344	45.622	44.399	0.966	0.971	0.967
		4000	48.389	49.178	48.430	0.981	0.983	0.981
	720	500	37.789	39.097	37.615	0.921	0.930	0.922
		1000	42.955	44.186	42.947	0.956	0.961	0.956
		2000	46.760	47.737	46.850	0.974	0.977	0.975

PSNR in i7-4702mq is about 1dB higher than i3-4160 and i5-6400 and SSIM in i7-4702mq is also higher than i3-4160 and i5-6400.

Is there a big different between i7 and i3, i5 when h.264 encoding?

[高__超]

There may be something wrong with the table.

[Anna_B_Intel]

Hi Gao,

Thank you for a report. Could you please provide me input video files that you used?

Best wishes,

Anna

[高__超]

Hi Anna,

Thank you for your reply.

I have used two videos:

afd_source_1080p_8000kbps.mov: http://pan.baidu.com/s/1dFuiQ5b

ring_source_1080p_10000kbps.mov: http://pan.baidu.com/s/1hrMSN5a

I use ffmpeg to convert them to YUV420p. And because they are too large, I only use parts of them. Below are the comand lines:

ffmpeg -ss 00:00:00 -i afd_source_1080p_8000kbps.mov -t 00:00:42 -s 1920x1080 -y -an -pix_fmt yuv420p  afd_1080.yuv

ffmpeg -ss 00:00:00 -i afd_source_1080p_8000kbps.mov -t 00:00:42 -s 1280x720 -y -an -pix_fmt yuv420p  afd_720.yuv

ffmpeg -ss 00:00:30 -i ring_source_1080p_10000kbps.mov -t 00:00:18 -s 1920x1080 -y -an -pix_fmt yuv420p  ring_1080.yuv

ffmpeg -ss 00:00:30 -i ring_source_1080p_10000kbps.mov -t 00:00:18 -s 1920x1080 -y -an -pix_fmt yuv420p  ring_1080.yuv

[Anna_B_Intel]

I can't download video from these links because of network error. Could you please compress files and attach to a comment at this topic?

Best wishes,

Anna 

[高__超]

The videos are uploaded in the attachment.

[Anna_B_Intel]

Thanks for providing files. What exact PSNR and SSIM did you use: PSNR-Y, PSNR-U, PSNR-V or PSNR-O? Is it average PSNR/SSIM or you measured worst case numbers?

Best wishes,

Anna

[高__超]

I get PSNR(among Y, U and V)/SSIM of each frame, and calculate the average of them.

[高__超]

Hi Anna,

Have you got the results of encoding performances between 4th i7 and 6th i5?

Look forward to your soonest reply. Thanks.

[david123456]

Hi Anna,

It's very interesting from gao c's results. Could you confirm the results?

Best regards,

David

[Anna_B_Intel]

Hello,

Sorry for delayed reply. I tried to reproduce the problem on i5-6260U (Skylake) and i7-4770K (Haswell), but PSNR and SSIM results were similar or even Skylake produced a little bit better quality. Check that you have the latest drivers and Media SDK/ Media Server Studio versions. Also you can update Samples version from here: https://github.com/Intel-Media-SDK/samples 

Best wishes,

Anna