Need advice when encoding x264/no-bframes

[HOLiC]

Hi, I'm trying to encode using x264/no-b frames. I don't care about the size, since I just want to compare the quality. But i need some advice regarding how to configure the options in x264.. well, I guess, i need somebody to tell me if my settings are wrong or correct.


C:\Program Files\Codec\x264\x264.exe --crf 14 --no-fast-pskip --filter 1,1 --subme 7 --trellis 1 --analyse all --8x8dct --qcomp 0.8 --direct none --scenecut 80 --me umh --cqmfile "C:\Program Files\Codec\custom_matrices_x264\eqm_avc_hr.cfg" --progress --no-psnr --output "C:\DVDrip\Trinity02\test.mp4" "C:\DVDrip\Trinity02\test.avs"



Hmm.. my question is.. should I turn on the deblock filter with 1,1 when using no-b frame? Is it okey that I'm using cqm file, Constant Quality instead of Constant Quantizer, trellis 1 when I'm not using b-frames? Oh, the source is anime by the way.
Thank You!!

[foxyshadis]

Do you really need to screw with scenecut for this? Trinity Blood uses fades like mad, there's probably only a half-dozen real cuts in the entire series. (Exaggerating a bit, but still.) I don't really know if the scenecut parameter is effective for fades. direct none is kind of redundant with no b-frames to apply it to. 1,1 filter is dependant on the effect you'd like to achieve, b-frames don't affect it at all, but it'll probably hardly affect anything since many frames will be right on or under the filtering threshold.

[HOLiC]

Oopse, I was thinking fade = scenechange. Yes, it does contain too much fading scenes, and thats why i thought extra i-frames would be better. I'll try with the default value, get rid of direct-none, and deblock..hmm, i'll first test with 1,1... Thank you very very very much foxyshadis. If you ever come to seattle, LET ME KNOW!! lol

[akupenguin]

Fades really want B-frames, not I. Or explicit weighted prediction, but I haven't written that yet.
The fact that fades do induce I-frames in many codecs just means that fades confuse scenecut detection, not that I-frames are desirable there.
I-frames in x264 never improve quality, the only reason they're used is to allow seeking. The purpose of scenecut detection is to put them where they cause the least damage.

[GodofaGap]

I-frames in x264 never improve quality, the only reason they're used is to allow seeking.
Can I ask then what the rationale is behind the default setting of ipratio 1.4 for is. If I frames never improve anything, it seems like a waste of bits (well a little bit of waste anyway). Or is it just a default setting that doesn't necessarily have anything to do with quality?

Or asked differently, would you say it would be safe to use ipratio 1.0?

[akupenguin]

Reducing the quantizer of the first frame in a scene helps. It would help just as much if that were a P-frame.
To put it another way: I give a quality boost to scenecuts. I put I-frames on scenecuts. One does not cause the other, it's just convenient for me to treat them together sometimes.

[HOLiC]

The purpose of scenecut detection is to put them where they cause the least damage.

Ahh, I see now..
Thank you akupenguin, for clear explanations!