What Kbps for x264 would i need to match a Mpeg2 kbps?

[Gruelius]

Hey all
Im making my dvd fileserver array muuch larger :D Anyway atm im just ripping all movies to be 1.5gb x264 mkv files including one ac3 original channel and subs. I want to know what way i can calculate the kbps so that it matches the dvd kbps's quality to make it seem to be a 1 to 1 film. It doesnt have to be perfect 1to1 but i want people to think they are watching dvd rips!

Im using Automkv with the better quality profile and the aq settings on recommended.

Thanks for the help in advance :D
Julius

[Dark Shikari]

It'll never be as good quality as the original; you always lose quality in re-encoding.

[Blue_MiSfit]

True.

There is no way to know how much bitrate will be required to make a movie be transparent to the source.

Don't worry about it.

Encode in CRF mode at CRF 18 - 22, depending on what looks good enough to your eyes. As an added bonus, CRF only needs one pass.

~MiSfit

[Gruelius]

Yeah im not talking 1:1 pixel's and that im more talking if people saw it they would asume its a dvd, the same if you saw vhs footage whether in avi format or a physical tape you would know its vhs footage:P

Im asuming when you say CRF you mean the constant quality profile?

is there a way to preview the quantitizer quality? And should i also apply those AQ Strength + AQ something settings?

Thanks.

[mahsah]

The easiest way to preview quality is to use avisynth's trim() function to cut a small section of video out and encode that.

[J_Darnley]

If you were using MeGUI then yes, it calls this rate control Constant Quality but I guess that AutoMKV calls it this too. Don't use the Constant Quantiser mode (if exists), simply put it will not allow the quality to be varied/shifted between frames.

I use a crf value of 21 which I think looks very good. I know it's not transparent, there are some small problems (banding and blocking) with smooth backgrounds but I fix these on playback. crf 18 produces files between 150 and 200% the size of crf 21 but do look somewhat better. Nearly all of my encodes have come out smaller that 1.5 GiB but then I filter noise out before encoding. Extended versions of LOTR and Gladiator have come out larger and perhaps one or two other longer films.

I don't know if AutoMKV includes the newest Variance AQ patch where it is on by default with safe values. But, I just took a quick look and it mentions "AQ 0.48" so that means that aq should be on with the defauts of --aq-strength 0.5 --aq-sensitivity 13. You shouldn't alter these without doing some testing on your video to see if you think it looks better.

I only have one suggestion about this. I think that on western style cartoons (e.g. The Simpsons, Family Guy, etc.) AQ seems to give no noticeable benefit and only increases file size for crf mode.