Morte66
12th October 2007, 13:32
So I entered the world of HD DVD. And I found it very good, except that I don't really like all that grain they went to so much trouble to retain. So I've been thinking about denoising, which means encoding since I can't run a good denoiser in real time. This is a slow process. Since I don't generally want to watch films more than once (or once per decade), I thought of making "disposable" encodes that I'd watch and delete. I'd give up compression to get speed whilst retaining quality. The ultimate answer would be HuffYUV, but that needs too much disc space. Xvid at q=2 is an option, but I never liked what Xvid's cooling/muting of colour. So I'm pondering x264 settings.
The fastest denoiser that seems worth it (fft3dgpu) does about 4fps. My normal DVD backup settings, which are meant for high quality and good compression, are --crf 18 --ref 3 --mixed-refs --no-fast-pskip --bframes 3 --b-pyramid --b-rdo --bime --weightb --subme 6 --trellis 1 --analyse all --8x8dct --threads auto --thread-input --progress --no-dct-decimate --no-psnr --no-ssim and they give me about 2fps encoding with a ~9kbps result that plays back on 55% CPU. I'd ideally like to get x264 to 2-4x times that encoding speed by expending bitrate, but not push the bitrate so high it interferes with smooth decoding.
I have no idea where to start, it's completely outside my normal experience. Presumably I'd go to --ref 1. Turning off --mixed-refs is a lot faster AFAIR. And I imagine I'd reduce --subme, but I'm not sure how far. But what about the b-frames? Do I turn them off, or just cut the quantity and features? Any other suggestions?
I expect I'll do a lot of fiddling, but I'd appreciate a few pointers on where to start.
The fastest denoiser that seems worth it (fft3dgpu) does about 4fps. My normal DVD backup settings, which are meant for high quality and good compression, are --crf 18 --ref 3 --mixed-refs --no-fast-pskip --bframes 3 --b-pyramid --b-rdo --bime --weightb --subme 6 --trellis 1 --analyse all --8x8dct --threads auto --thread-input --progress --no-dct-decimate --no-psnr --no-ssim and they give me about 2fps encoding with a ~9kbps result that plays back on 55% CPU. I'd ideally like to get x264 to 2-4x times that encoding speed by expending bitrate, but not push the bitrate so high it interferes with smooth decoding.
I have no idea where to start, it's completely outside my normal experience. Presumably I'd go to --ref 1. Turning off --mixed-refs is a lot faster AFAIR. And I imagine I'd reduce --subme, but I'm not sure how far. But what about the b-frames? Do I turn them off, or just cut the quantity and features? Any other suggestions?
I expect I'll do a lot of fiddling, but I'd appreciate a few pointers on where to start.