Speeding up 1st pass?

[Manaka]

Currently I'm using the same settings on both passes. Is there anyway to disable some settings to speed up 1st pass but still keep up the quality ?

Here my settings


start /b /low x264_64.exe --pass 1 --bitrate 12011 --stats ".stats" --level 4.1 --ref 4 --mixed-refs --no-fast-pskip --bframes 3 --b-adapt 2 --b-pyramid --weightb --direct auto --deblock -3:-3 --subme 9 --trellis 2 --psy-rd 0.9:0.1 --partitions p8x8,b8x8,i4x4,i8x8 --8x8dct --chroma-qp-offset -4 --vbv-bufsize 50000 --vbv-maxrate 50000 --me umh --merange 32 --threads auto --aq-strength 0.8 --progress --no-dct-decimate --no-psnr --no-ssim --output NUL "underworld32.avs" 2> outputfile1.log

start /b /low x264_64.exe --pass 2 --bitrate 12011 --stats ".stats" --level 4.1 --ref 4 --mixed-refs --no-fast-pskip --bframes 3 --b-adapt 2 --b-pyramid --weightb --direct auto --deblock -3:-3 --subme 9 --trellis 2 --psy-rd 0.9:0.1 --partitions p8x8,b8x8,i4x4,i8x8 --8x8dct --chroma-qp-offset -4 --vbv-bufsize 50000 --vbv-maxrate 50000 --me umh --merange 32 --threads auto --aq-strength 0.8 --progress --no-dct-decimate --no-psnr --no-ssim --output "underworld.mkv" "underworld32.avs" 2> outputfile2.log


Sorry about my bad english :o

[Dark Shikari]

--chroma-qp-offset -4what are you doing?

[LoRd_MuldeR]

Use "--me dia" and remove "--trellis" for the first pass.

[Sharktooth]

you can also reduce the number of reference frames to 1, subme to 2 and partitions none (this is on the first pass).
also you can safely remove --no-dct-decimate and --chroma-qp-offset -4 from BOTH passes.

[Manaka]

thank guys :D

and what about --merange and --b-adapt ? Should I use on both passes?

[Sharktooth]

frametype decisions are made on first pass, so... --b-adapt 2 should stay.
merange can be lowered instead, but if you use --me dia on first pass there is no point in lowering it. just remove the merange option from the first pass.

[Manaka]

thanks again. But I wonder does it hurt the PQ? Gonna make some tests though :D

[LoRd_MuldeR]

thanks again. But I wonder does it hurt the PQ? Gonna make some tests though :D

All the settings that have been suggested to lower in the first pass will NOT hurt the final encode from the second pass in a noteworthy way.

GUI encoders like MeGUI will lower these options automatically for you in the first pass when you run a 2-Pass encode (unless you disable the "Turbo" option).

[Manaka]

Fantastic!!! I went from 4.75 fps to 19.49 fps on 1st pass :D. BTW it just used only 30% of my CPU though(i7 920@3.2Ghz). Any suggestions? Should I run two 1st pass of two different movies at the same time? :P

[Sharktooth]

you should try to use a multithreaded/accelerated DEcoder for your source and check what happens
oh... you can remove --no-fast-pskip too (from both passes)...

[Manaka]

you should try to use a multithreaded/accelerated DEcoder for your source.

My source is AVC H264 and I used ffdshow x64 to decode it(already set decoding threads in decoder options to 8) :(

[Sharktooth]

uhm... what filters are you using in your .avs script?
(--no-fast-pskip can be removed in the "fast" 1st pass too... just in case you want to keep it for the 2nd pass...).

[Manaka]

uhm... what filters are you using in your .avs script?
(--no-fast-pskip can be removed in the "fast" 1st pass too... just in case you want to keep it for the 2nd pass...).

My AVS

DirectShowSource("underworld3.grf",audio=false)
Crop(0,140,0,-140)

I encode HD on vista x64 so I have limited filter to use though :(

[Sharktooth]

ah... maybe you could ask neuron 2 for a 64bit build of DGAVCdecNV (http://forum.doom9.org/showthread.php?t=141104) (if you have a supported videocard).

[Comatose]

Last time I checked Vista x64 runs 32-bit programs just fine...

[Manaka]

Last time I checked Vista x64 runs 32-bit programs just fine...

But I want to use x264 x64. I have 6GB RAM so..;)

BTW Is it possible to encode 2 movies at the same time? (1st pass only )

[Sharktooth]

sure.

[roozhou]

But I want to use x264 x64. I have 6GB RAM so..;)

BTW Is it possible to encode 2 movies at the same time? (1st pass only )

Of course you can. This is the best way to increase CPU usage.

BTW try using ffdshow's built-in cropping filter instead of avisynth's.

[nm]

My source is AVC H264 and I used ffdshow x64 to decode it(already set decoding threads in decoder options to 8) :(
Have you also set "ffmpeg-mt" as H.264 decoder instead of "libavcodec"?

[kemuri-_9]

Have you also set "ffmpeg-mt" as H.264 decoder instead of "libavcodec"?

last i checked, the ffdshow mt branch was x86 only, the x64 version does not exist....

[nm]

last i checked, the ffdshow mt branch was x86 only, the x64 version does not exist....
Could be so, I can't install the x64 version of ffdshow in Wine to check. At least the 32-bit branches of ffdshow and ffdshow-mt have been merged.

Anyway, if ffmpeg-mt or some other multi-threaded decoder is not in use, that could be a major bottleneck in the first encoding pass. In that case a 32-bit chain might be faster overall. The standard libavcodec H.264 decoder is also threaded, but it only works for sliced streams.