MeGui and lossless x264

[Selur]

Can someone say something whether or not motion estimation&co, trellis, number of reference frames etc. have any influence on the size of the output file when the lossless mode is selected?

Will some even cause that the lossless mode is no longer lossless? (e.g. noise reduction ;) )

:thanks:

Cu Selur

Ps.: for those who are interessted, I did some tests:

Lossless 1
--qp 0 --ref 6 --mixed-refs --no-fast-pskip --bframes 6 --b-pyramid --b-rdo --bime --weightb --direct auto --nf --subme 7 --trellis 2 --analyse all --8x8dct --b-bias 20 --me esa --threads auto --thread-input --progress --no-psnr --no-ssim --output "G:\lossless1.mp4" "G:\filmworks\Wunder.avs"
Speed: 6,87fps
Size: 77,6 MB

Lossless 2
--qp 0 --no-cabac --subme 1 --analyse p8x8,b8x8,i4x4 --me dia --threads auto --thread-input --progress --no-psnr --no-ssim --output "G:\lossless1.mp4" "G:\filmworks\Wunder.avs"
Speed: 36,46fps
Size: 90,8 MB

Lossless 3 (Load Default + High Profile + Lossless)
--qp 0 --analyse p8x8,b8x8,i4x4 --threads auto --thread-input --progress --no-psnr --no-ssim --output "G:\lossless 3.mp4" "G:\filmworks\Wunder.avs"
Speed: 19,9fps
Size: 78,4 MB

Lossless 4 (Load Default + High Profile + Lossless + Deblocking off)
--qp 0 --nf --analyse p8x8,b8x8,i4x4 --threads auto --thread-input --progress --no-psnr --no-ssim --output "G:\filmworks\Wunder.mp4" "G:\filmworks\Wunder.avs"
Speed: 19,98fps
Size: 78,4 MB

Lossless 5 (Load Default + High Profile + Lossless + CABAC off)
--qp 0 --no-cabac --analyse p8x8,b8x8,i4x4 --threads auto --thread-input --progress --no-psnr --no-ssim --output "G:\lossless 8.mp4" "G:\filmworks\Wunder.avs"
Speed: 29,8fps
Size: 89,9 MB


Lossless 6 (Load Default + High Profile + Lossless + Subpixel Refinement 7)
--qp 0 --subme 7 --analyse p8x8,b8x8,i4x4 --threads auto --thread-input --progress --no-psnr --no-ssim --output "G:\lossless 5.mp4" "G:\filmworks\Wunder.avs"
Speed: 12,01fps
Size: 78,1 MB

Lossless 7 (Load Default + High Profile + Lossless + Number of Reference Frames 6)
--qp 0 --ref 6 --analyse p8x8,b8x8,i4x4 --threads auto --thread-input --progress --no-psnr --no-ssim --output "G:\lossless 6.mp4" "G:\filmworks\Wunder.avs"
Speed: 17,4fps
Size: 77,6MB

Lossless 8 (Load Default + High Profile + Lossless + Macoblock Options -> All)
--qp 0 --analyse all --8x8dct --threads auto --thread-input --progress --no-psnr --no-ssim --output "G:\lossless 6.mp4" "G:\filmworks\Wunder.avs"
Speed: 17,08fps
Size: 78,8MB

[bond]

what does this have to do with megui?

[Selur]

The connection with MeGui is, that MeGui restricts you in some options when selecting lossles and I was wandering if the restrictions make any sense. ;)
e.g. additional to the features I used above one can still modify Quantizer settings and iirc, there should be no quantization when encoding lossless ;)

Cu Selur

[check]

settings that do not affect lossless output in x264 will just be ignored by x264 if you pass them to it. Either that, or it will chuck a wobbly and crash. Either way, if you are looking to report a bug use the tracker.

[Selur]

@check: It's more the question if this is a bug or if this is intended. ;)