Please critique my x264 settings!

[Mixer73]

Thanks, I was wondering about that.

I've just done a test encode, I gotta say the quality vs speed is stunning. Around 2x realtime on my Q6600, wow.

[RunningSkittle]

huh 2x realtime with --preset veryslow ? I dont think so...

[Groucho2004]

Originally Posted by RunningSkittle

huh 2x realtime with --preset veryslow ? I dont think so...

Maybe overclocked to 20 GHz

[MatLz]

I beat him:
Preset veryslow at 6x realtime on my crapold dualcore...
My secret: pointresize(4,4)

[Mixer73]

Originally Posted by RunningSkittle

huh 2x realtime with --preset veryslow ? I dont think so...

The whole thing ran at 66FPS. SD resolution. I'm changing GUIs so I at least have all the current settings at hand.

Now that I have more comments about multi pass quality-based encoding and such I will need to spend some time doing some more tests before I can come back with a 'new' setting that people can critique.

Thanks all for your feedback.

[MatLz]

(Return to serious mode)

Originally Posted by Mixer73

multi pass quality-based encoding

After all the explanations you got on this thread...I hope you simply forgot the ' , ' ? Am I right?

[Mixer73]

Originally Posted by MatLz

(Return to serious mode)After all the explanations you got on this thread...I hope you simply forgot the ' , ' ? Am I right?

Well comments = people saying it doesn't work. Xvid4PSP is certainly doing something with its multiple passes, even if its just basically selecting a bitrate for me. Obviously I'm the only freak around using these settings.

Well I'm going to spend some time playing with Staxrip so I can get a feel for the current settings, my previous GUI doesn't seem really relevant to x264 as its currently implemented so if I'm going to use x264 well I need to take Dark Shikari's advice and use the presets rather than re-inventing the wheel.

I think the job for me now is to try single pass quality encoding vs 2pass encoding and see how the results stack up vs filesize.

I'm very encouraged by what I have learned so far so thanks all for your help and I'm sorry I was so far off the page

[Chengbin]

Originally Posted by Mixer73

Well comments = people saying it doesn't work. Xvid4PSP is certainly doing something with its multiple passes, even if its just basically selecting a bitrate for me. Obviously I'm the only freak around using these settings.

Well I'm going to spend some time playing with Staxrip so I can get a feel for the current settings, my previous GUI doesn't seem really relevant to x264 as its currently implemented so if I'm going to use x264 well I need to take Dark Shikari's advice and use the presets rather than re-inventing the wheel.

I think the job for me now is to try single pass quality encoding vs 2pass encoding and see how the results stack up vs filesize.

I'm very encouraged by what I have learned so far so thanks all for your help and I'm sorry I was so far off the page

Let me make this very clear.

There is ABSOLUTELY NO DIFFERENCE in quality between multi pass and CRF given the same bitrate and settings. You are WASTING TIME if you do 2 pass encoding when you don't care about having a strict final size.

Got that?

[Mixer73]

Originally Posted by Chengbin

There is ABSOLUTELY NO DIFFERENCE in quality between multi pass and CRF given the same bitrate and settings.

I understand this, but I am hoping that by using the quality modes I might be able to achieve smaller files than by setting the bitrate explicitly.

Its my understanding of compression in general that multi pass will let you get a lower bitrate for the same effective quality.

Also quality mode with a higher preset might be a better balance of quality vs time than 2-pass, this is what I want to test.

[LoRd_MuldeR]

Originally Posted by Mixer73

I understand this, but I am hoping that by using the quality modes I might be able to achieve smaller files than by setting the bitrate explicitly.

That makes no sense. By using 2-Pass mode and setting the target bitrate explicitly, you already define final file size!

file_size = bitrate * duration

If you want a smaller file, simply lower the bitrate accordingly. Yes, it really is that easy

Originally Posted by Mixer73

Its my understanding of compression in general that multi pass will let you get a lower bitrate for the same effective quality.

Wrong. 2-Pass mode gives you the best possible quality for a given target bitrate or a given target file size, but it doesn't generally compress more efficient than CRF mode!

In fact a video encoded with 2-Pass mode will have (almost) identical quality compared to a video encoded with 1-Pass CRF mode -- given that both videos have the same average bitrate (file size).

The difference is that with CRF mode the final file size is completely unpredictable, while the final size is known in advance when using 2-Pass mode

Conclusion: If you need to hit a specific file size or a specific bitrate, then go with 2-Pass mode. But if you want to hit a specific level of quality and don't care about filesize, then use CRF mode.

[qyqgpower]

I think there're still some features working better in multi-pass than crf mode, like --direct auto.
But since the frame decision is done in 1st pass, unless one uses high precision 1st pass settings,
they would obtain worse decision with fast 1st pass+slow 2nd pass than simply slow crf mode.

[ajp_anton]

Simplified:
CRF: You choose a quality, x264 will encode.
2-pass: You choose a bitrate (filesize). On the 1st pass x264 finds out what quality will fit into that size, and the 2nd pass it encodes with that quality.

[Chengbin]

Originally Posted by qyqgpower

I think there're still some features working better in multi-pass than crf mode, like --direct auto.

You get such a negligible increase in quality you can probably say you don't get any.

[zamwow]

Originally Posted by Dark Shikari

1. Your commandlines won't even work. You can't use multi-pass with CRF.

Anyone mind giving me the list of things that doesn't work with CRF?

[Dark Shikari]

Originally Posted by zamwow

Anyone mind giving me the list of things that doesn't work with CRF?

--pass > 1
--bitrate

[zamwow]

Originally Posted by Dark Shikari

--pass > 1
--bitrate

oops, thought the things in bold needed more than 1 pass to work. My mistake.

[Carpo]

Ok i dont know if this is x264 related or dgindexnv but will try here first, I am using the latest x264 from x264.nl (at this time 1373) and i am using

D:\>x264.exe --profile high --level 4.1 --preset veryslow --tune film --pass 1 --bitrate 9132 --stats "stats" --slow-firstpass --thread-input --b-adapt 2 --ref 4 --partitions all --me umh --direct auto -o gran.torino.mkv gran.torino.avs

But it seems like x264 is stalling, the cpu useage is at 0%, CUVIDServer is running (used to pipe the dgv to avisynth) can anyone see anything wrong with the above?

Thanks, if this isnt a x264 issue i will post in nvtools thread

[J_Darnley]

I have experienced this a few times and after using VDub and avs2yuv. Make sure that there is not another instance of a script using DGSource. Close it if there is. If not, try restarting the cuvid server then running x264 again.

[LoRd_MuldeR]

Well, if you open the very same AVS file in VirtualDub, can you play it up to the point where x264 freezes and beyond that point?

[Carpo]

Originally Posted by LoRd_MuldeR

Well, if you open the very same AVS file in VirtualDub, can you play it up to the point where x264 freezes and beyond that point?

Yes plays fine, thing is it seems random, i started the encode last night, woke up this morning and it said 32% - 0% cpu usage, i thought the CUVIDServer had stopped but it was still there so i started the encode again, it stopped on 7.3% this time.

I wondering if its something in the above line that is causing x264 to kick out, and therefore i will need to correct it, or if its a dgindexnv issue

Originally Posted by J_Darnley

I have experienced this a few times and after using VDub and avs2yuv. Make sure that there is not another instance of a script using DGSource. Close it if there is. If not, try restarting the cuvid server then running x264 again.

only things running are the server avisynth and x264 and the only things that are in the avs file is:

loadplugin("D:\dgdecnv200b6\DGDecodeNV.dll")
dgsource("D:\gran.torino.dgv", resize_w=1280, resize_h=720)