conversion of Xvid.avi files to Xvid.avi files or Divx.avi files

[kingoffish]

How to convert Xvid.avi files to Xvid.avi files or Divx.avi files with the quality factor from 0.14 to between 0.2 and 0.28.

[G_M_C]

How to convert Xvid.avi files to Xvid.avi files or Divx.avi files with the quality factor from 0.14 to between 0.2 and 0.28.

Google on it, or try reading some other parts and/or threads on this forum and/or the frontpage (EDIT: Googleling and reding the threads here, probably comes down to the same thing ;) ). This whole forum pratically deals with encoding, re-encoding or transcoding. There even are several threads that solely speak about quality-factors, and threads that give ideas on how to try to improve quality of video-clips....

So, my guess is that you've just put a question here, without doing much research or reading yourself. And what do you expect from us now ?

[buzzqw]

and remember that you cannot trasform a ugly divx in a beauty divx... (quality's speaking... without calling Didee filters's..)

BHH

[DarkZell666]

What do you call quality factor ? This means nothing and could mean anything at the same time.

The closest thing I can think about is the bpf (bits per pixel per frame) value, which doesn't mean that much either, but here goes anyway :

total_number_of_pixels = x_resolution * y_resolution * fps * length_in_seconds

filesize_in_bits = filesize_in_MBytes * 1024 * 1024 * 8

bits/pixel = filesize_in_bits / total_number_of_pixels

The bits/pixel value is what you would seem to want to be equal to ~0.2.

Example: a 640*480 movie @ 25fps which lasts 2 hours contains 55,296,000,000 pixels. If you encode that movie to be 700MB (5,872,025,600 bits), you'll achieve: ~0.106 bpf (which isn't much at all).

There are many bitrate calculators out there that will do these calculations for you though.

[kingoffish]

I have search the thread but can't find anything about quality factor, If can, can you give the link about quality factor. What some of you said, do you mean when encording, I can't change the quality factor from 0.14 to 0.2 to 0.28?

[henryho_hk]

I am afraid there is no common single definition of quality factor. Even at the same bit/pixel, there are many other parameters that (greatly) affects the quality.

You can also improve the playback quality by, for example, deblocking, sharpening, etc.

[CWR03]

I have search the thread but can't find anything about quality factor, If can, can you give the link about quality factor. What some of you said, do you mean when encording, I can't change the quality factor from 0.14 to 0.2 to 0.28?
From what source are you getting your reference of quality factor? You asked for a link to "quality factor" when you're the only one who seems to know what this means. kingoffish, please post your reference of "quality factor" so we know what exactly your goals are.

[kingoffish]

What is the quality factor QF ? What are the recommended values ?

The QF corresponds to the number of bits by pixel and by frame. As a rule of thumb, the higher it is, the better the image is. However, the size of the movie is limited by the size of the support (in general, 1 or 2 CD), thus the number of bits is limited, and a compromise has to be found between compression and quality. The QF depends on the bitrate and the image resolution. In general, to increase the QF, the movie resolution is decreased, since the bitrate depends on the support size and the movie length, which are fixed values.
Below 0.18, you obtain often a low quality image, since there are not enough pixels to encode with enough detail : you get a lot of squares, a very "blocky" image. As a rule of thumb, recommended values are 0.20-0.22 for 1CD and 0.26-0.28 for 2 CDs.
The QF value is variable : it is sometimes possible to go as low as 0.18 for Bergman, but not for Matrix. However, going above 0.30 is an overkill.

The --check-comp option is used to make a compressibility check on a sample of the movie, taken at different positions. Thus it helps choosing the optimal QF for that particular movie.

I get it from http://tuxrip.free.fr/faq_en.html

[foxyshadis]

BPF is a Divx3-era concept. It's as outdated as a 55mph speed limit. (I normally drive 105...) It doesn't work at all at HD and QCIF resolutions, the "good" values are totally different. If you lean too heavily on BPF you'll get lower quality movies, because you'll resize down much more than you need to. And if you do it in Gordian Knot you'll overfilter anyway.

Instead, see the "Xvid presets" topic to find out how to configure xvid to best suit your quality needs. This is the modern incarnation of the compressibility check.

Never heard BPF called a "quality factor" though. For good reason - it isn't one.

[DarkZell666]

@kingoffish: Do you know how to read ? Look at my previous post ! It's all about calculating your QF value (which is rather called BPF in fact) !

Dammit, you asked for help and completely ignored it. 'Ya gotta learn to read and understand man ...

+1 for foxy's hint, BPF is a rule of thumb, nothing more (I did say it didn't mean much, either I'm ghastly-transparent, or the guy needs some goggles ... :o)

[HeadBangeR77]

1) One of the most popular AVI analyzing tools, G-Spot (:D), describes BPF as "Qf." and "Frame Quality" - other similar tools might do the same, I don't know for sure, however.

2) Gordian Knot speaks of BPF as "rough output quality indicator".

... hence it might be misleading for beginners, if
... the above progs (and probably some more) didn't speak of BPF at the same time :p

@kingoffish:
As already written in one of the previous posts, you will not gain any visual quality by transcoding video files, you might only loose it.

You could bump up the above mentioned BPF (or "quality" factor, as you call it) by transcoding for instance 1CD rip (XviD) into 2CD rip (DivX or XviD). Then you would see it gave you nothing for the obvious reason - lost details can't be recovered. You have my word that such a transcode would look as bad/good as the original rip. Savvy? ;) ;) ;)

[CruNcher]

@ dasiy0627

http://forum.doom9.org/showthread.php?p=931244#post931244

[BigDid]

... you can convert(encode) them to to compress or reduce the space the data occupies with high quality factor such as mp4,3gp for you can preview profile

http://www.my-video-converter.com/images/profile-ipod.jpg
Hi,

Once again, (see:http://forum.doom9.org/showthread.php?p=969656#post969656) do not take doom9 readers for ...what they are not.
The linked software is not freeware, it should be mentioned and you really should be aware of rule5:
5) Do not spam. No blatant advertising.

Did

[foxyshadis]

Daisy, you were suspended once for breaking the spam rule. Showing up just to spam your software again will certainly result in another suspension and may lead to a permaban. Please stop linking to your software every chance you get, and stop reviving threads to do it.

Also a particularly strange definition of "freeware", which appears to mean nagware/demoware in this care.