x264 BD compliant "perfect" settings

[Valeyard]

Okay, so let's have a look at the settings I generally use. First this is what the --preset values mean...

- medium: default settings:
(--b-adapt: 1 --direct spatial --me hex --rc-lookahead 40 --ref 3 --subme 7)
- slow:
--b-adapt 2 --direct auto --me umh --rc-lookahead 50 --ref 5 --subme 8
- slower:
--b-adapt 2 --direct auto --me umh --partitions all --rc-lookahead 60 --ref 8 --subme 9 --trellis 2

Those are probably the ones you want to look at for the most part. Note that of course blu-ray compatibility (/L4.1) is limited to 4 reference frames for 1080p and 5 for 720p (not 9, although it is a legal value for L4.1 it's not for BD), and the default partitions setting (so setting --ref above "5" or --partitions to "all" has no effect).

Here are my usual settings:

Code:

--tune film --profile high --level 4.1 --bluray-compat --threads 8 --keyint 230 --open-gop --b-adapt 2 --b-bias 3 --slices 4 --vbv-bufsize 14000 --vbv-maxrate 14000 --aq-strength 1.5 --me umh --ref 4

[spoRv]

Thanks for your hints!

I left out --open-gop because I noted some standalone players seem to not like it a lot... am I wrong?

[Feallan]

--open-gop (or open_gop=1 ?) seems to be necessary for MPC-HC to seek properly.

[Valeyard]

Andrea- Closed GOP has advantages, each GOP is self-contained so you'll be able to split the file losslessly at any GOP. Open GOP means if you want to split your (already encoded) file losslessly you have to find a closed GOP (and most will be open) - if you cut the video at an Open GOP your last B-frame will suffer a loss of information. That might be required if you were planning on making a mutli-angle video for instance, but you can get around that limitation by simply encoding the file in parts in the first place.

I believe seeking is only a problem for the MP4 container, which hardly anyone would want to use over MKV nowadays. It shouldn't cause any issues with M2TS files. I believe it's because MP4 thinks that GOPs are the seek points rather than the RAPs (random access points) encoded in the x264 bitstream. But yes, you're right, the MP4 container can't correctly handle Open-GOP material.

[Feallan]

I had the seeking problem with both M2TS and MKV.

[Valeyard]

Well it certainly shouldn't, because it's a part of the blu-ray spec. Although you don't have to use it when encoding, players must support it.

Did you have any trouble with the Jurassic Park MKV seeking (assuming that you downloaded it)?

[Feallan]

No, because JP release has open gop.

It's a part of BD spec, but I'm only talking about MPC-HC (and likely other players) having problems with closed gop.

[Valeyard]

That's interesting because my MPC-HC has no issues (1.7.9 x64) - it can even seek from MP4 files which have open-gop x264 streams in them. My guess is it's an issue with the decoder and not MPC itself. Although if you're already using the latest version of LAV then I'm out of ideas.

[Feallan]

It happened on various versions of MPC-HC and LAV, including the most recent one, for me and at least one more person. No idea why, VLC played the file fine.

[spoRv]

...it seems I should use the open gop at the end!