x264 log

[xxxThiefxxx]

Lets say we have this log info

x264 [info]: frame I:1484 Avg QP:14.29 size: 90921
x264 [info]: frame P:37244 Avg QP:16.66 size: 34497
x264 [info]: frame B:139328 Avg QP:18.70 size: 14036
x264 [info]: consecutive B-frames: 2.4% 1.7% 4.9% 22.6% 18.3% 31.9% 6.1% 8.6% 1.2% 0.6% 0.5% 0.8% 0.2% 0.1% 0.2%
x264 [info]: mb I I16..4: 5.6% 76.0% 18.4%
x264 [info]: mb P I16..4: 0.6% 13.4% 1.4% P16..4: 28.4% 33.8% 13.2% 2.4% 0.2% skip: 6.6%
x264 [info]: mb B I16..4: 0.1% 1.5% 0.2% B16..8: 34.3% 23.4% 4.9% direct: 5.7% skip:30.0% L0:45.0% L1:44.1% BI:10.9%
x264 [info]: 8x8 transform intra:84.4% inter:55.3%
x264 [info]: coded y,uvDC,uvAC intra: 92.1% 80.4% 61.2% inter: 24.6% 19.1% 4.5%
x264 [info]: i16 v,h,dc,p: 20% 20% 5% 55%
x264 [info]: i8 v,h,dc,ddl,ddr,vr,hd,vl,hu: 10% 8% 10% 10% 13% 12% 13% 11% 13%
x264 [info]: i4 v,h,dc,ddl,ddr,vr,hd,vl,hu: 11% 9% 6% 10% 15% 13% 13% 10% 13%
x264 [info]: i8c dc,h,v,p: 41% 27% 18% 14%
x264 [info]: Weighted P-Frames: Y:8.0% UV:4.1%
x264 [info]: ref P L0: 44.2% 8.2% 17.9% 7.4% 6.1% 4.5% 3.9% 2.2% 2.0% 1.7% 1.6% 0.3% 0.0%
x264 [info]: ref B L0: 68.2% 12.7% 6.9% 3.5% 2.7% 2.3% 1.7% 1.1% 0.6% 0.3%
x264 [info]: ref B L1: 92.0% 8.0%
x264 [info]: kb/s:3636.03
x264 [info]: encoded 178056 frames, 3.11 fps, 3636.03 kb/s, duration 15:54:58.00

I trying to use different setting each time to see if there is improvements... So, how i understand when quality is improved? When number, percentages etc. increasing or when decreasing?

[poisondeathray]

You can't tell from the log numbers only - The numbers by themselves do not necessarily indicate anything - you have to use your eyes

This might be helpful
http://mewiki.project357.com/wiki/X264_Stats_Output

If you use --ssim or --psnr, it will print ssim and psnr numbers - those correlate more with quality but even they don't have perfect correlation (quality is subjective, not objective parameter - it cannot be measured accurately) . Higher numbers are better, but there are a lot of problems with these numbers - your eyes are still the best. For example you can use --tune ssim or psnr and get better numbers, but the "subjective quality" according to most eyes is usually worse

http://en.wikipedia.org/wiki/Peak_signal-to-noise_ratio
http://en.wikipedia.org/wiki/Structural_similarity

You can only compare versions with the same bitrate - so either 2pass or do multiple fractional CRF runs until the bitrates become equal

There is still a lot of information which can be helpful , but none of them can tell you directly about "quality" . For example higher runs of consec b-frames usually indicate more compression (but B-frames have lower quantizer than P or I), in some cases like lower bitrate scenarios it may help overall quality. On very high bitrate scenarios, it will actually be worse

[xxxThiefxxx]

It's so complicated... video encoding is very difficult...

[jagabo]

Be careful about using too many ref-frames, and b-frames, etc. Many standalone players (Blu-ray players that play MKV files, for example) have limitations on what they can handle.

[Hoser Rob]

It's so complicated... video encoding is very difficult...

You're not kidding ... a lot of the problem is there is no decent standardization. I just don't want to be a digital video geek that much. I guess I'll stay an audio geek.

It's not well standardized because video is so hardware dependent. You can't abstract the process that much, you have to get into the nuts and bolts.

I think the main thing is that those video codec standards are not written for people like me who just want to rip/encode their dvds. They are professional standards.

Some computer tasks are relatively simple and can be solved just by plugging in numbers. There are tons of threads here posted by newbies who expect video encoding to work like that.

It doesn't. It's one of those tasks that takes judgment. I.e knowing how to interpret all those numbers.

You shouldn't be discouraged from learning all this stuff just because I don't want to. But be prepared to do research. Lots of it.

[jagabo]

The x264 presets and tunings are adequate for the average user.

http://mewiki.project357.com/wiki/X264_Settings#preset
http://mewiki.project357.com/wiki/X264_Settings#tune

You can also start with those and add your own fine tuning.

[jman98]

Some computer tasks are relatively simple and can be solved just by plugging in numbers. There are tons of threads here posted by newbies who expect video encoding to work like that.

At some point you have to decide that what you are getting is good enough and get on with your life or you headed down the path of insanity. We have a thread here that is due for reactivation any time now. The original poster started it over a year ago and he brings it back to life every month or so. Basically he's trying to record VHS tapes and he is never satisfied with what he gets, so after a year of trying, he's still stuck at the very beginning of his quest, having accomplished nothing. I would encourage like the OP here to just find something he can live with and get on with his life rather than going down this path of "Can I make it a little bit better?" that he seems to be heading towards where nothing he does is ever really good enough, so he keeps redoing it over and over.

[xxxThiefxxx]

Does it matter what program I use to encode? For example if I will use exactly same settings in 3 different program, the speed of encoding, the quality of movie and the size of file will be the same?

[jagabo]

Does it matter what program I use to encode?

In practice, yes. Many front ends for x264 don't give you access to all the settings. And different programs may do different preprocessing. For example, one may inverse telecine an DVD source, another may not, or they may use different methods.

[xxxThiefxxx]

Can you tell me the best out there? I currently using xvid4psp...

[somespirit]

you can look at these .....

x264 [info]: frame I:1484 Avg QP:14.29 size: 90921
x264 [info]: frame P:37244 Avg QP:16.66 size: 34497
x264 [info]: frame B:139328 Avg QP:18.70 size: 14036

lower Average QP means better quality for I, P and B frames respectively

here some explanation about x264 log - http://mewiki.project357.com/wiki/X264_Stats_Output