我又做了一个简单的测试,使用的片源是Chobits的NCOP。
首先我使用我一直以来做DVDRip用的参数,在crf18下,以r1195版本进行了1pass的压制。- avis [info]: 704x480 @ 23.98 fps (2336 frames)
- x264 [info]: using SAR=40/33
- x264 [info]: using cpu capabilities: MMX2 SSE2Fast SSSE3 Cache64
- x264 [info]: profile High, level 4.1
- x264 [info]: slice I:39 Avg QP:13.23 size: 21536 PSNR Mean Y:53.35 U:55.41V:56.60 Avg:53.75 Global:49.70
- x264 [info]: slice P:930 Avg QP:15.56 size: 11159 PSNR Mean Y:48.90 U:54.54V:55.38 Avg:49.78 Global:47.02
- x264 [info]: slice B:1367 Avg QP:17.43 size: 2578 PSNR Mean Y:46.41 U:52.17V:52.82 Avg:47.34 Global:45.86
- x264 [info]: consecutive B-frames: 8.9% 32.8% 26.1% 12.7% 9.4% 2.6% 4.9% 1.0% 1.6%
- x264 [info]: mb I I16..4: 44.9% 29.2% 25.9%
- x264 [info]: mb P I16..4: 11.4% 8.8% 5.7% P16..4: 36.5% 16.2% 9.3% 0.0% 0.0% skip:12.1%
- x264 [info]: mb B I16..4: 3.5% 1.8% 0.4% B16..8: 29.5% 1.8% 2.2% direct: 3.0% skip:57.8% L0:46.5% L1:44.6% BI: 8.9%
- x264 [info]: 8x8 transform intra:32.8% inter:51.8%
- x264 [info]: direct mvs spatial:88.1% temporal:11.9%
- x264 [info]: coded y,uvDC,uvAC intra:64.3% 69.6% 35.9% inter:18.7% 21.9% 6.2%
- x264 [info]: ref P L0 64.4% 14.6% 8.5% 4.0% 3.1% 2.3% 1.9% 1.1%
- x264 [info]: ref B L0 75.9% 11.1% 5.5% 2.8% 2.0% 1.5% 1.2%
- x264 [info]: SSIM Mean Y:0.9903087
- x264 [info]: PSNR Mean Y:47.518 U:53.165 V:53.901 Avg:48.422 Global:46.332 kb/s:1210.44
- encoded 2336 frames, 5.67 fps, 1210.63 kb/s
复制代码 r1195的crf18得到了码率1200K,接下来,我用r1268,在保持所有参数不变的前提下,关闭了mbtree,以1200K码率进行了2pass的编码- avis [info]: 704x480 @ 23.98 fps (2336 frames)
- x264 [info]: using SAR=40/33
- x264 [info]: using cpu capabilities: MMX2 SSE2Fast SSSE3 Cache64
- x264 [info]: profile High, level 4.1
- x264 [info]: frame I:39 Avg QP:13.52 size: 20717 PSNR Mean Y:53.32 U:55.32V:56.53 Avg:53.69 Global:49.66
- x264 [info]: frame P:932 Avg QP:15.50 size: 10972 PSNR Mean Y:48.90 U:54.48V:55.40 Avg:49.75 Global:47.44
- x264 [info]: frame B:1365 Avg QP:17.60 size: 2607 PSNR Mean Y:46.49 U:52.26V:52.90 Avg:47.41 Global:46.25
- x264 [info]: consecutive B-frames: 8.8% 32.4% 28.3% 11.5% 10.7% 2.1% 3.7% 1.0% 1.6%
- x264 [info]: mb I I16..4: 42.1% 26.3% 31.6%
- x264 [info]: mb P I16..4: 7.8% 6.4% 8.2% P16..4: 38.9% 16.6% 9.4% 0.0% 0.0% skip:12.6%
- x264 [info]: mb B I16..4: 3.4% 1.5% 0.6% B16..8: 33.7% 1.9% 2.2% direct: 3.3% skip:53.4% L0:46.2% L1:43.9% BI: 9.9%
- x264 [info]: 8x8 transform intra:28.1% inter:39.7%
- x264 [info]: direct mvs spatial:70.8% temporal:29.2%
- x264 [info]: coded y,uvDC,uvAC intra: 56.1% 55.1% 31.3% inter: 18.5% 17.7% 6.6%
- x264 [info]: i16 v,h,dc,p: 45% 26% 22% 7%
- x264 [info]: i8 v,h,dc,ddl,ddr,vr,hd,vl,hu: 29% 15% 38% 2% 2% 5% 2% 4% 3%
- x264 [info]: i4 v,h,dc,ddl,ddr,vr,hd,vl,hu: 33% 13% 40% 2% 2% 4% 1% 2% 1%
- x264 [info]: ref P L0: 62.0% 15.3% 9.1% 4.4% 3.4% 2.5% 2.0% 1.2%
- x264 [info]: ref B L0: 75.4% 11.4% 5.7% 2.7% 2.0% 1.5% 1.2%
- x264 [info]: SSIM Mean Y:0.9905871
- x264 [info]: PSNR Mean Y:47.561 U:53.195 V:53.958 Avg:48.450 Global:46.727 kb/s:1198.19
- encoded 2336 frames, 6.08 fps, 1198.19 kb/s
复制代码 参数不变,打开mbtree,2pass编码- avis [info]: 704x480 @ 23.98 fps (2336 frames)
- x264 [info]: using SAR=40/33
- x264 [info]: using cpu capabilities: MMX2 SSE2Fast SSSE3 Cache64
- x264 [info]: profile High, level 4.1
- x264 [info]: frame I:39 Avg QP:14.38 size: 21184 PSNR Mean Y:52.98 U:54.21V:55.63 Avg:53.22 Global:50.16
- x264 [info]: frame P:934 Avg QP:17.07 size: 11250 PSNR Mean Y:49.13 U:54.56V:55.55 Avg:49.96 Global:47.98
- x264 [info]: frame B:1363 Avg QP:19.28 size: 2412 PSNR Mean Y:46.39 U:52.53V:53.11 Avg:47.32 Global:46.58
- x264 [info]: consecutive B-frames: 8.7% 33.6% 27.2% 11.0% 10.2% 1.8% 4.9% 1.0% 1.6%
- x264 [info]: mb I I16..4: 44.4% 25.4% 30.2%
- x264 [info]: mb P I16..4: 10.0% 6.3% 6.2% P16..4: 38.1% 15.3% 8.8% 0.0% 0.0% skip:15.3%
- x264 [info]: mb B I16..4: 1.7% 1.1% 0.5% B16..8: 32.7% 1.8% 1.8% direct: 3.0% skip:57.5% L0:47.4% L1:41.8% BI:10.8%
- x264 [info]: 8x8 transform intra:28.4% inter:41.8%
- x264 [info]: direct mvs spatial:64.9% temporal:35.1%
- x264 [info]: coded y,uvDC,uvAC intra: 45.6% 47.7% 24.1% inter: 17.1% 15.8% 6.0%
- x264 [info]: i16 v,h,dc,p: 54% 26% 13% 8%
- x264 [info]: i8 v,h,dc,ddl,ddr,vr,hd,vl,hu: 30% 15% 36% 2% 2% 6% 2% 4% 3%
- x264 [info]: i4 v,h,dc,ddl,ddr,vr,hd,vl,hu: 35% 12% 37% 2% 3% 5% 1% 3% 1%
- x264 [info]: ref P L0: 62.0% 15.9% 9.3% 4.3% 3.3% 2.4% 1.9% 1.1%
- x264 [info]: ref B L0: 77.2% 11.3% 5.4% 2.4% 1.6% 1.2% 0.9%
- x264 [info]: SSIM Mean Y:0.9908447
- x264 [info]: PSNR Mean Y:47.597 U:53.371 V:54.127 Avg:48.477 Global:47.137 kb/s:1200.50
- encoded 2336 frames, 7.99 fps, 1200.50 kb/s
复制代码 PSNR我只是顺便计算了,不过我们无视掉它好了,只看SSIM就够了
r1195 crf 18: SSIM Mean Y:0.9903087
r1268 no-mbtree: SSIM Mean Y:0.9905871
r1268 mbtree: SSIM Mean Y:0.9908447
这是SSIM的比较结果,再看看各自的平均QP
r1195 crf 18:
x264 [info]: slice I:39 Avg QP:13.23
x264 [info]: slice P:930 Avg QP:15.56
x264 [info]: slice B:1367 Avg QP:17.43
r1268 no-mbtree:
x264 [info]: profile High, level 4.1
x264 [info]: frame I:39 Avg QP:13.52
x264 [info]: frame P:932 Avg QP:15.50
x264 [info]: frame B:1365 Avg QP:17.60
r1268 mbtree:
x264 [info]: frame I:39 Avg QP:14.38
x264 [info]: frame P:934 Avg QP:17.07
x264 [info]: frame B:1363 Avg QP:19.28
结果很有意思,打开了mbtree之后,平均的QP都比前两个有所提高,但是SSIM却没有降低,不知道这是不是dark shikari嘴里所说的Magic XD |