Megabytes per minute.

[Stan64]

The guides says that you should always use a filesize to limit the bitrate to. That's easy when you do CD rips or similiar. But when you record alot of clips that can vary from 1-15 minutes, are there some good size per minute that people prefer. What do you like and what is your opinion. I think that 12 meg per minute is good.

[Audionut]

I've always just used a target bitrate.
Always get about 5kbps under set target.

[Stan64]

What target bitrate do you use then?

[Tuning]

I would advise to do a compressibility test on every clip you encode. Some times, the clip may not be compressible as other ones.

Therefore doing a compressibility check will ensure same compressibility is obtained..and no wastage of bitrate for highly compressible clips.

[Stan64]

"compressibility check"?

I do 2 passes. O_o And you two got off topic.

What bitrate/filesize settnigs do you use and throw in an opinion?

[manono]

Hi-

No, he didn't go off topic, and I thought his point was a good one. If you choose a common bitrate (which is equivalent to a fixed MB/Minute), and they all have the same resolution and other settings, because the different videos will compress differently, the result will be videos of differing quality. His suggestion was to run a compress test on all of them first, to help choose the bitrate for each, so that the resulting videos will have roughly the same quality.

My suggestion would be slightly different, and faster as well. Do them all with one pass and a common quantizer. So, for decent quality for them all, you might consider running one pass at quant 3.

are there some good size per minute that people prefer
What bitrate/filesize settnigs do you use

Those questions are so vague as to be almost meaningless. There are so many variables that come into play-resolution, filters used, matrix, B-Frame settings, etc.

[Stan64]

I understand your point. And I'm not out to get the same quality on all captures (I capture game recordings). I record new ones all the time and can't line them all up. And pople who download don't want a file that is 3 minutes and 110 megabytes. My question concerned mostly what filesize a minute should be around in general.

I don't care if a anime episode take 170 or 230 megabytes but some people do. The bigger one do mostly have better quality but some people don't care.

I got some tips though that I can use. ^^

And I wan't to do a good looking rip. All the guides is for making a rip fit onto a cd. I know how to make rips. I have done them that way myself. Since you started with divx3.11 SBC. I have read many mpeg-4 tech (and XviD) docs and I know how all the options work in XviD. This is a thing that isn't covered though.

And I didn't like to be told to do 1-pass when I have spent the last week reading all guides and reading much of the forum threads and so on. And read complementary documents faqs have linked to and so on. =P

[ObiKenobi]

Well how big of a file do you want? Once you decide, from there you just do Filesize in MB/number of seconds. And from there you will get the bitrate you will want to use. There is no universal setting for anything, so asking what filesize should be used in general really isn't a question that can be answered objectively. You have to decide on your own and test, and if you don't like the results change your settings.

This post is sort of bordering on breaking the "Do not ask "what's best" because this question cannot be answered objectively. Each and everyone has their own view about what's best in a certain area. The best is what works best for you!" rule.

[Stan64]

I didn't ask for guidance. I wanted impact on what settings others used in the filesize area. I'm not asking for a optimum setting. I use a filesize that is around 12 meg per minute. A game-rip in that quality isn't really large and you can see everything well. I use 1300 in bitrate. The guides say that you should use filesize setting. And I asked what others used. I did not believe that there was a optimum setting nor that the filesize setting was the best one. That's why I clearly ask for what others use and their opinion in my first post.

But I got roughly misjusted and we went away talking about something else. Excuse my bad english and poor sentence making skills. it must be because of those everyone seems to misunderstood/judged me.

[Tuning]

Stan64, your first question cannot be answered correctly, because all of us have experience on different kinds of clips and all of them needed some tweaking etc.

What we ususally do is to setup everything except bitrate. Then we do a compressibility check which will give the approx compressibility of the used clip. Here compressibility means 'How much compression can be done' so that the final output is small in size and best in quality.

What I'm trying to say is bitrate 1300kbps (as you said) may be good for some clip, while insufficient for some other.

Even sometimes, this bitrate is a overkill..eg, highly compressible movies. (Film with lot of darkness...Like The Matrix ). In this case you may not need 1300kbps, it requires only less than that. The result is lower file size.

Therefore by doing compressibility check you can have lower file size if clip is highly compressible.

[Stan64]

Ok, how do I do a compressbility check then? ^^

Ok, fooled around a little. I might tell you what I use as source and what I use to encode.

I capture film in full NTSC to huffyuv, interlaced of course (VirtualDub_sync). I then load it into VirtualDubMod. I apply these settings:

Filter:
Crop (some pixles)
Discard field 2 (I want to do progressive scan at the best setting but the file is going for double size then.)
Resize it as near the original it can be with correct aspect ratio

XviD:
Quant: MPEG
Adaptive Quantization
GMC
B-VOPs (default numbers)
Closed GOV

1st - Full quality, discard
2nd - all defaults

Target bitrate: 1300

Zones - one zone with chroma optimizer

Advanced:
Motion Search 6
VHQ 4
Use chroma motion
Maximum I-frame intervall 300 (29.9697fps on source)
Quantization: all defaults


I tried to do a compressbility check in auto gknot, I had to open the captutre file in a avs. And when it was done it said:
Result: 180224 pixels 704 Blocks
Result: 0.000 Bits per pixel

And how do I do a compressbility check with the filters I want to use? If I wanna do a Progressive Scan movie (100fps.com way) then it has another compressbility. O_O

[OBcecado]

Ok, you should've read the guides ;)
Look here (http://www.doom9.org/gknot-main5.htm), more specifically right here (http://www.doom9.org/gknot-xvid.htm).


Greetz.

[Stan64]

I have read them, read my edited post above.

[Audionut]

Just run a first pass on the material at any settings you want.

Take note of the bitrate used for the first pass.

If the bitrate used for the first pass was 2500kbps then obviously or not, using a bitrate of 2500kbps for the second pass, will ensure a high quality encode.

What I generally do is run the first pass through. Then do the second pass for as long as I could be bothered waiting.

Load unfinished pass 2 file and look at the quality.

Quality = shite = increase bitrate.
Quality = good = leave or decrease bitrate.

[Tuning]

Originally posted by Stan64
And how do I do a compressbility check with the filters I want to use? If I wanna do a Progressive Scan movie (100fps.com way) then it has another compressbility. O_O

Just as normal create the AVS file with all required filters...then load in GK and do the compressibility check. ;)

[pogo stick]

Or if you don't want to use AviSynth and Gordian Knot you can do this way:
Run first pass with whatever VirtualDub filters you want.
Download Bugsan's Xvid Stats Viewer here (http://forum.doom9.org/showthread.php?s=&threadid=67639).
Load first pass Stats file in Viewer.
Look for "Total video size".
That will be max filesize you will get in second pass using min Quantizer=2 (http://www.vslcatena.nl/~ronald/docs/xvidfaq.html#C13) .
Than you can take 60-80% of max filesize and if you don't like resulting video increase it.

And you also can look here (http://forum.doom9.org/showthread.php?threadid=44414), if you didn't.

Or use Koepi's StatsReader instead of Bugsan's Xvid Stats Viewer if you don't have Java Sun JVM.

[unmei]

my rule of thumb is 10 mo/min including audio, but recently i often end up in the 8 mo/min range.

[Stan64]

Thanx for all the info. Are there any AviSynth FAQs that explains how to load vdub filters and set them and so on? O_o

Then I should be ready to test some more myself. =D

[ObiKenobi]

Yeah from the avisynth's site's own faq.

http://www.avisynth.org/index.php?page=Section+4%3A+Importing+filters+from+VirtualDub

[Stan64]

Thanx! ^^