Isn't DivX really low quality?

[Gameshow Host]

I keep hearing people here talking about using DivX for capturing their videos.

Maybe I'm wrong about this, but I have always understood that DivX was ONLY a Web format, and not an option for storing your own videos. DivX, is very low quality and should only be used for making a tiny video file that can be quickly streamed or downloaded over the Internet. I have downloaded DivX files and they're really small (maybe a couple of megs per minute). I thought DivX was not an option for home usage, and if your video isn't going to be transferred over the Internet then you should never use DivX, and stick with MPEG2 (or MPEG1). But I have heard DivX mentioned so many times here that I'm starting to wonder if DivX can somehow be set up to store high quality video.

[Mirror_Image]

http://www.divx.com/support/faq.php

[Gameshow Host]

Thanks. I read the FAQ. The DivX website says that it can be used for anything, but it's heavily implied that Internet transfer is its main objective. It also says that you can set the bitrate to anything you like, however the "suggested" example bitrate given is extremely low, and I suspect DivX is not designed to be used for high quality video such as MPEG1 and MPEG2. Later in the FAQ they say that they think their codec is better than "the others" - presumably meaning MPEGs 1 and 2.

I still don't know if DivX should - or can - be used for home use. But I suspect it shouldn't.

One thing I certainly do not like about the DivX movies I have downloaded in the past is that they are really unresponsive when you move the playback head. They always take a few seconds to respond. For me, this is not acceptable. I want my movies to instantly update when I slide the playback head. So I wouldn't use it for that reason alone.

[pacmania_2001]

DivX can be off very high quality if encoded correctly. Divx usually has comparable quality to MPEG(1 or 2) but with smaller file sizes. The disadvantages are that it cant be played on DVD players

[Mirror_Image]

Begging the Question
( petitio principii )

--------------------------------------------------------------------------------
Definition:
The truth of the conclusion is assumed by the premises.
Often, the conclusion is simply restated in the premises in a
slightly different form. In more difficult cases, the premise is
a consequence of the conclusion.

[Greg12]

DIVX was orignally a hack of MS MPEG 4 (the drivers were forbid to be used for AVI)

DIVX is designed to deliever near DVD quality, while fitting onto a standard CD-ROM.

DIVX is kind of like how MP3 is.

MP3 made it possible to transmit songs in minutes.

It used to take days to download videos, if anyone would even try.

Now with DIVX, anyone with a cable modem or dsl can download in a few hours

[Gameshow Host]

you said:

>DIVX is designed to deliever near DVD quality, while fitting onto a >standard CD-ROM.

and

> DIVX is kind of like how MP3 is.
> MP3 made it possible to transmit songs in minutes.

So DivX is near DVD quality, but can be quickly transmitted over the Inernet. I wish that were true, but surely that can't be right. The DivX movies I have seen were fairly small files, and full resolution; but they were not MPEG2 quality by any means.

[ovejon]

it all depends on the source and how they encoded it. the same thing happens when a person rips a dvd to vcd or svcd. And yes divx quality can be compared to dvd, u should see X_tv series that i dwl from the net they look sweet!!!!!!!!!!!!!!!!! :D

[Sulik]

Divx, like MPEG4 and H.263 are optimized for low-bitrates, so they will look much better than MPEG1/MPEG2 at low bitrates (ie for internet or other low-bandwidth transmission).

The main reason why they look better is the de-ringing and de-blocking filters that removes the blocking and ringing artifacts that you see in MPEG1/2.

At high bitrates, ie 6-8Mbps for DVD resolutions, you will not see any difference between DivX and MPEG1/2.

[Greg12]

you can't directly compare mp3 and divx though.

What i'm saying


Orignally a wav file (the only way to transmit sound) was 20-40 megs. Then came MP3 and they were shrunk to 4-5 megs.


Orignally AVI was the only way to transmit video. AVI's were several gigabytes. Videos' could be 6 gigs or so

DIVX shrinks them down to 200-700 megs.

[dumwaldo]

dont judge something by what you have downloaded.

a poor quality encode is a poor quality encode no matter what format it comes in.

in my experience i would have to say they are all excellent formats when used right with the only real difference being the file size.

the exception to that rule would be low bitrate files where divx out performs mpeg 1 or 2. encode a divx at 500 Kb/s and it will look far better than an mpeg 1 or 2 encoded at 500 Kb/s. encode a divx at 1150 Kb/s and it will look about the same as a mpeg encoded at 1150 Kb/s. for that reason divx is often associated with low quality video simply because its better at low quality than others not because it can not produce high quality.

divx does have a bitrate ceiling though because the very high level of compression it uses. basically you will get to a point where you have achieved full compression and your source has no more information to offer.

i hope that clears up some of your confusion about divx. if you want to know more i would suggest checking out www.divx-digest.com and avoiding divx.com. the divx site itself is rather biased and has their own intrests in mind, divx-digest is more independent, like this site, and would probably offer a better perspective

[FiEND]

Theres soooo much more to it than that. and please don't try saying a divx at 1150 is equal to mpeg at 1150. mpeg isn't 1/3 the quality of a divx. Mpeg2 (SVCD) is comparable but twice the size _and_ the audio in the mpeg2 isn't as good.

Divx3x is a hack of mpeg4. Divx4 and 5 are not. They are separate and quite different codecs.

Yes, divx can be a web format. It is very scaleable in quality and size. The same video can be done 2MB or 200MB. Same as one could do with mpeg, but the quality is much better for size.

If there is a cap on divx, it is because divx has no hardware assist. when you play a mpeg, your video card has hardware to assist in the decoding. Divx has none, meaning it is 100% CPU. But then again, there is also overkill. I cannot imagine a divx encode that requires a 6000kbit encode. VBR peaks maybe, but that is pushing it also.

here are a couple samples. I saved em in .png so I wouldn't make the quality worse thus they are a bit large.

sample 1 - right click open new window
sample 2 - right click open new window

[Thorn]

Divx as a format suffers from the same problem as all other formats: the people encoding with it. It is technically capable of providing amazing video quality, but any codec will produce crap when the resolution and bitrate are too low. VCDs and SVCDs are a little more reliable because if you started with a good source you can't compress it into oblivion. Since there are so many modem users still, many people encode to a certain bitrate, regardless of quality. With divx you have the option of encoding well or encoding to be as small as possible, and most free content on the web is usually encoded for size, not quality.

[Gameshow Host]

Greg12>> You're comparing DivX to mp3, and I see your point - that DivX is a solution to allow high quality yet small files to be transferred over the Internet. However, mp3s - despite being lossy - aren't audibly different to the original, whereas DivX is visibly different to the original. At least I think it is. If you could encode something in DivX so that it appeared identical to the original to the human eye then DivX would be a miracle!


Sulik>> Thanks. A very useful summary of DivX application.

dumwaldo>> Again, thanks for the info. Very interesting.

FiEND>> When you say that MPEG isn't 1/3 the quality of a Divx, do you mean at low bitrates or at ALL bitrates? Sulik pointed out that DivX is optimised for low-bitrates - so isn't there a chance that its optimisation for low bitrates could make it lesser quality at higher bitrates?

What do you mean by "cap", by the way? Do you mean how slow it is to playback?

Interesting pictures. I'm intrigued... which episode of TNG was that? And have you bought all 7 seasons?


Everyone>> I don't remember where I've read it, but I've read it many times: Divx is low quality and should only be used for transferring small files over the Web. It may be just a myth - but I've heard it so many times I always assumed it was true.

[jeex]

this is the way i see.. divx (well encoded) is good for watching once.. but if you plan on keeping the movie, svcd is the way to go. it may take up more discs, but the quality is atleast equal to or better than divx, plus you can play it on the vast majority of dvd players.. and later on when dvd recording becomes more prevelant svcd will look heaps better than divx..

[FiEND]

FiEND>> When you say that MPEG isn't 1/3 the quality of a Divx, do you mean at low bitrates or at ALL bitrates? Sulik pointed out that DivX is optimised for low-bitrates - so isn't there a chance that its optimisation for low bitrates could make it lesser quality at higher bitrates?

all bitrates. but you have to think like this (but ignore the names). divx low motion is like mpeg1. and divx fast motion is like mpeg2. low motion is much better for smaller caps, 352*240, whereas fast motion is better for large resolutions.

What do you mean by "cap", by the way? Do you mean how slow it is to playback?

i didn't mention a cap, the other guy did. I dont believe there is a cap on divx. I just think there is a point where quality meets overkill. same as mpeg, you can capture at 9000kb but the last 5000Kb will be overkill and not do much for the image. also as i mentioned pure cpu power is a limiting factor. it is easy to create a divx that only a p4-2600 can play, but the quality wont be better - just overkill.

Interesting pictures. I'm intrigued... which episode of TNG was that? And have you bought all 7 seasons?

that one is eps 1x20 - Heart of Glory. I havent bought any, just capped em all. I just downloaded that DVD rip cause I didn't burn the cd yet so I replaced my own cap. I think only the first season was released on DVD so far.

I don't remember where I've read it, but I've read it many times: Divx is low quality and should only be used for transferring small files over the Web. It may be just a myth - but I've heard it so many times I always assumed it was true.

i guess codec is like cars or cpu's. i have rarely run into anyone who praises Ford and Chevy or Intel and AMD or DivX and Mpeg.

personally, I like one of each as well. Though I do enjoy svcd's alot, I wouldnt keep one. I have a dvd drive and decoder card with svid and audio out to TV. so svcd is great. i also have tv out on my video card for watching divx. in the end i prefer divx.

fortunately with the release of divx5 alot more movies will be ripped onto 1 cd rather than 2 cds which was normal for a long time with HQ Divx movies.

fyi. some game makers will be using divx for their in game movies... I heard Blizzard was one of them.

also I read in europe they are or will be soon, testing divx streams from satelite. i give mpeg a few more years being mainstream, then divx will start taking over. everything from videophone to satelite to digital cable etc. never know though, technology only moves as fast as money allows, so it could be 20 years like HDTV.