bluray profile overkill?

[gahz]

i'm not asking if this profile i have chosen for the average bluray is the best, i'm just wondering if most people think it is overkill.

program --preset veryslow --tune film --crf 21.0 --bframes 5 --ref 10 --aq-mode 2 --subme 9 --no-dct-decimate --no-fast-pskip --output "output" "input"

any input on tuning it would be appreciated. oh i almost forgot, this is the settings i use for archiving and all are at 1080p.

[mp3dom]

What's the purpose? Is this a profile for encode a (source) bluray or for authoring a (destination) bluray? In the latter case, you're completely out of specs.

[AlekseiV]

Is it too slow? Then it's overkill.

[gahz]

@mp3dom - goes on my media server. direct play via mediaportal with no intention of ever worrying if it will play on stand alone products or not.

@alekseiv - well too slow is relative but i am comfortable how much time it takes right now since i have a dedicated computer on the side that does the transcoding 24/7 and i'm not on a time table. right now the most i'll go is 20 hours per movie. i suppose if my computer was slower i'd have to turn the settings down a bit.

do my parameters look ok though? are there any redundant settings or anything else funky i did? thanks guys for the replies.

[Sharktooth]

no they dont.
use --preset slow --tune film --aq-mode 2 --crf 21
that's all. if it's too "fast" try --preset veryslow.
the remaining options you added are useless.
if you want to make it blu-ray compatible then there are other options and most of them are mandatory (--level 4.1 --keyint 24 --min-keyint 2 --open-gop bluray --b-pyramid strict --ref 4 --weightp 0 --slices 4 --vbv-bufsize 30000 --vbv-maxrate 40000 --aud --nal-hrd vbr --colorprim "bt709" --transfer "bt709" --colormatrix "bt709"). plus the video should be in a supported resolution and framerate.

[mp3dom]

open-gop/weightp 0/colorprim/transfer/colormatrix are not really mandatory :)

[moviefan]

With regard to your multimedia equipment, I would recommend to obey DXVA specs as they - from my point of view - don't hurt quality and give you the option to decode the movies with your PC's graphics card. Also, such a high number of reference frames probably slows things down without a real gain. 4 or 5 reference frames should be enough for most movies.

[Sharktooth]

open-gop/weightp 0/colorprim/transfer/colormatrix are not really mandatory :)

infact i said "most of them"

[gahz]

@sharktooth - i don't need it to be bluray compliant. i play these movies off a dedicated pc using mediaportal. what i had originaly done was set it to preset slower and made a couple tweaks. i think the only thing i changed was aq mode and subme. can you please explain which options you view as useless?

@moviefan - i dont need dxva compliancy. i dont even need it to decode via graphics card as i have an i3 doing the deed. yes i know an i3 is probably overkill for an htpc but i got a decent deal on it. i actually decreased the ref frames from the slower setting (at least i think it's slower, 1 down from placebo). as far as encode time goes i'm really ok with the duration right now. i dont want it to take longer than what it is at though is why i didnt go even higher on some settings like bframe.

what i'm after is to be as transparent as possible with at least a 50-60% reduction in size. i know it's not going to be a perfect copy and i'm ok with that. i also know that i can fine tune each setting per source but i would rather have a universal profile.

the setting that really confuses me though is the aq mode i have chosen because i couldnt really find much to read on the experimental setting one.

[Sharktooth]

--no-dct-decimate, --no-fast-pskip, the changing of ref frames and b-frames numbers (since you have already specified --tune film) and --subme 9 (since you have already specified --preset veryslow).
those are the useless options.

[mp3dom]

i dont even need it to decode via graphics card as i have an i3 doing the deed. yes i know an i3 is probably overkill for an htpc but i got a decent deal on it.
Small OT: i3 is a great processor for HTPC since it require few watts to work and doesn't dissipate so much heat. With proper heatsink and a small undervolt you could think to work near-fanless. Anyway DXVA compliancy could be a great thing if you're using the integrated GPU as this completely offload the CPU (so less heat and power).
As stated above, so much refs and bframes probably slowdown the encoding without adding so much quality. You could think to lower the CRF value to gain some quality with an increased bitrate.

[Sharktooth]

http://www.asrock.com/nettop/overview.asp?Model=ION%20330HT

... or build it by yourself: http://www.zotacusa.com/products/motherboards/intel/ion

[gahz]

i'm sorry i had made the mistake of saying that i started with the slower slide setting when in fact i start it on very slow setting.

@sharktooth - are you saying that those settings are already checked off in the very slow setting? when i choose advanced after moving the slider to slower i dont see those 2 settings checked. as far as changing the vales for r and b frames what i did was lower the values for both because it was taking longer than i liked.

@mp3dom - temp isn't much of an issue and yes i undervolt everything i can. i dont need it to be dead silent as the computer is in a diff room.

@sharktooth - i did build it myself. i guess i shouldnt have said htpc since most people use mini/micro cases for those. the case i use is pretty large: http://www.xoxide.com/lian-li-pc-343b-case.html reason i went this route because i didnt want to setup a rack just for storage. this case allows me to keep everything in it which is much simpler (it also doubles as an end table haha). i know most people tell me to not even transcode due to the storage capacity i have but i just like to do it :)

[pokazene_maslo]

IMHO you should always obey L4.1 unless you have a pretty good reason not to. i3 has integrated graphics chip that has integrated hardware decoder for h264. Everything that you need to change in your settings is to lower number of refs. Lowering refs to around 4-5 will speedup encoding with small quality loss, that quality loss can be compensated with for example increasing subme to 10.

[Sharktooth]

im saying that those settings are unnecessary and give a very small quality boost (if any at all) at the expense of speed.
setting a high number of b-frames is ok unless you set also --b-adapt 2 (since it's not multithreaded). however a high number of ref frames slow down the encoding in any case.
so keeping a sane number of b (in case of --b-adapt 2) and ref frames makes it possible to set the subme higher and gain more quality/compression at the same speed cost.

[gahz]

@pokazene - setting L4.1 is for hardware decoding via graphics card yes? is there a good reason i should choose to have video decoding over cpu if my cpu does it fine?

@sharktooth - wow thank you for that explanation. that actually helps out a whole lot. is subme 10 really that much better than 9? last i read up on it people weren't very convinced. you had stated that b-adapt 2 is not multithreaded. does this mean that i would actually gain a small amount of time if i did multiple encodes at the same time vs just 1 at a time?

[Sharktooth]

i dont know if subme 10 is really so much better but having to much refs is not usefull at all, it just wastes your CPU time. IMHO doing multiple encodes and rising b-frames with b-adapt 2 is not a good choice either.
i would prefer a 100% CPU utilization (or very close to it) and 1 encode at a time. so i would optimize the settings to get that result.

[Audionut]

@Sharktooth,

x264 now automatically sets --min-keyint with the formula

keyint/10

[gahz]

@sharktooth - is the reasoning behind lowering the number of ref and b frames just for the sole purpose of speeding up the encode? if so, then would it still not make sense to keep the number of frames i have set if i was entirely comfortable with the amount of encoding time? i dont mind having a single movie take 20 hours to complete as i have the option of using multiple oc'd i7's if i so choose to. actually i suppose i could take a trip down to sony films and use multi cpu xeon transcoding servers if i was really wanting to speed things up :)

hmm i didnt mean to make myself sound arrogant, i guess i was just trying to convey that i am totally ok with how much time it takes to encode a single file right now with my settings. i just dont want to waste time though if i have redundant settings or settings that dont make sense. thanks for all your input sharktooth.

[AnonCrow]

Is there a good reason i should choose to have video decoding over cpu if my cpu does it fine?
Because decoding with a GPU can be close to an order of magnitude more efficient than decoding with the CPU.

Btw, you haven't mentioned if you use the IGP in i3, or a discrete card ?


After encoding a few movies with --bframes 5 --ref 10 ,
did you check x264 output to see how often the max number
of frames were actually used ?

[pokazene_maslo]

@pokazene - setting L4.1 is for hardware decoding via graphics card yes? is there a good reason i should choose to have video decoding over cpu if my cpu does it fine?
Not only graphics card, also standalone hdd players like popcorn hour use hardware acceleration. Decoding via graphics card will consume much less power and will produce less heat.

[Sharktooth]

@audionut: thank for the info :)

@gahz: what i tried to say is subme 10 is probably more "convenient" than a high number of b or ref frames coz those could be not used depending on the source and just slow down the encoding. a higher subme is always better instead... even if slightly.

[gahz]

@anoncrow - i use a dedicated vid card, ati 4550 i think it is. what's odd is that my vid card gets really hot and my cpu does not even though i'm decoding with my cpu. at least that's what windows tells me i'm doing. as far as the frame usage, i havent checked the ref frames part but most of my stuff is having the highest usage at 5bframes. they might use higher but at badapt 2 it slows down quite a bit when i go over 5bframes.

@sharktooth - i never thought of it that way. it makes perfect sense now. the way i had it set would only be better IF my encode actually used that many ref and b's yes?

[Sharktooth]

exactly.

[creamyhorror]

For live action DVDs, it seems to me that many films use significant numbers of 5, 6 or 7 b-frames. I'd advise staying at at least 5 b-frames (little point going over 7). For reference frames, 6 is about as many as you'd want AFAICT. It's quite possibly different for Blu-rays, though.

[me7]

With my --preset veryslow 720p encodes, I usually see a lot of usage for up to 8 reference frames. B-frames go up to 11 with >1% usage according to the stats on many sources.

[Sharktooth]

on what --b-adapt settings?

[me7]

--b-adapt 2 (implied by -preset veryslow), but there are also a lot of sources that don't go higher then 8 consecutive b-frames at all. Maybe I just had a few "lucky" encodes in a row that cloud my judgment, but my experience is that >8 b-frames are used with b-adapt 2 and b-pyramid from time to time (though it's still possible that they only add little to compression efficiency).

EDIT: from the stats of my Shutter Island encode (BluRay source, downscaled with Spline36Resize to 720p):

x264 [info]: consecutive B-frames: 1.5% 1.9% 5.5% 15.2% 15.0% 41.1% 7.6% 3.0% 2.5% 1.5% 1.4% 1.3% 0.6% 0.5% 0.6% 0.4% 0.4%

encoded with --preset veryslow --crf 18 --bframes 16 --open-gop display

[gahz]

@me7 - i had also started to notice this. i had my bframes set to 8-9 at one point but proved to take too long to encode for my taste. two of my sources, firefly and terminator tv series both, were showing 6-7 bframes as the highest count.

[me7]

Another interesting observation: Kick Ass, downsized to 720p with Spline36Resize, encoded with "--preset veryslow --tune film --crf 18.0 --bframes 16 --open-gop normal"

x264 [info]: consecutive B-frames: 1.7% 2.2% 7.0% 18.6% 16.7% 38.6% 6.3% 2.0% 1.0% 0.7% 0.5% 0.6% 0.2% 0.1% 0.1% 3.7% 0.1%

A lot of 15 frames usage, 14 and 16 are barely used though.

[Sharktooth]

more than 5 bframs starts to be almost useless when you compare the encoding time.
on that situation i would use 5 b-frames and rise some other option (like subme for example).