why do I loose quality when going form AVI to MPEG2 same siz

[smokedvw]

why do I loose quality when going form AVI to MPEG2 same size?
Like if it is a 600mb avi and i make the mpeg2 file 600mb it looks way worse?
is there somting i should do, should i change it to mpeg1? or do I have to make the file large to have good qulitly?
Thanks

[ohbwian]

So your converting a 600mb avi into a 600mb mpeg2? Are you getting the full movie? How are you doing it and what programs are you using?

[puertorican138]

Yes, but it won't be very noticeable. :P

[Donny661]

Whenever you convert from a different type of lossy compression you will ALWAYS loose quality, even if you recompress to the same compression you will still loose quality. Do you know what compression your .avi file uses? If you downloaded it from the internet it is most likely a DivX encoded file, DivX is based on mpeg-4 which can produce much smaller files with better quality than mpeg-2(especially if your trying to achieve same filesize), but DivX is only compatible with maybe 4 DVD players and those only came out within the past year and are rather expensive. Try reading different articles/guides/faqs on this site and also try www.doom9.org to learn more.

[vhelp]

.
.
..and don't forget that those DVD players were built w/ divX in mind.
Only they support divX 4x and 5x - I think its so that they don't
violate any copyright laws or something like that, by using divX v3.11
(was a hacked version of M$ mpeg-4 codec)

And, yes, it's quite obvious that you have a divX clip. And, at 600mb,
I would say that it's not in the best quality (more than likely) especially
if its more than 60 minutes and D/L'ed off the web.

Also, don't forget other factors/specs that the user forgot to mention.
* resolution - his is probably 320x240 maybe
* framerate - 15fps or some odd 18fps etc.
* time - 60 minute 90 minute 2 hours, etc. ??
* size - 600mb for example (see time)
* and a few other things I might have missed here

All these above will factor into this users poor quality video conversion
experience.

I say, no standards, no quality - thats all.
In my divX endeavors, so far, I haven't come up w/ a standard to stick to.
I'm still working on this. But, I can conclude thus far, that two standards
may need to be made - one for FullScreen and other, for WideScreen.
Sound, is another, to factor into this so called standard.. bitrate, format,
etc., then comes the actual size per time per media capacity etc.
hmmm, I guess I should say, process too. ie, how one Encodes to divX and
w/ what settings, etc. hmmm.. No-one whats to do ANY work on this. That's
why we have so many issues. Oh well.

-vhelp

[smokedvw]

Yes, but it won't be very noticeable. :P

it is very noticable, because if the is a change in camera position or a quick movemnt the screen will blur or create boxes.
I usually just do a 2 disc 80min svcd.
But I like the 1 disc option but it makes the quality pritty poor.
Most of my AVI are 25 or 29.97 fps and most are dvix.
I guess it comes down to how bad of quality I want.
Thanks,
Also when you said there are players which play dvix is it copied as an ISO or how is it created and burned on the cd's?
Thanks

[Conquest10]

you can use one of kwags templates and get pretty good quality on one disc.

[ricardo2]

If you have an uncompressed avi file,you won't see the difference.But divx compressed avi's are already highly compressed,so the result will be poor.And remember,an extension "avi" does mean a hell lot of variables.

[Conquest10]

but on the net .avi always means a highly compressed divx file.

[crahak]

Well, I don't bither with avi's from the web, quality isn't really there. As for conversions from them, it only gets uglier. And even with anyone's templates, you can only fit so much per disc and keep good quality. I have yet to see a good quality 1 CD movie (unless it's like 45 minutes long), regardless of the format.

DivX isn't standard, that is also one of it's strenghts. A Properly encoded DivX with high enough reolution, proper AR, and high enough bits/(pixel*frame) do look good. On the web, you get bad AR's, bad IVTC's, ridiculously low bits/(pixel*frame), low resolutions and the like. So anyone who tries to convert them and expects quality... Especially if the source and destination are both on a single CD, and the movie is like 2 hours...

We could speak about this for ages anyhow...

[smokedvw]

you can use one of kwags templates and get pretty good quality on one disc.

what do you mean?

[Conquest10]

i mean you can use his templates instead of the video cd templates that are bundled with tmpgenc.