High bitrate a must for good looking rips?

[ChannelK]

Please help to me understnd divx5 a little better. As far as i can see the fundamental building block for vidoe compression is the bitrate. I cannt understand no matter how much postprocessing, filtering etc. a low bitrate movie, say <1000 kbps can be anywhere near dvd quality. I havent been able to acheive using divx5.02 (for 1oo min+ movies) a 1 cd rip that i would class as great quality. Do I need to experiment with divx5 pro a bit more, or is my understanding correct, that if i want what i class great quality, you need bitrate which means 2 cds for over say 100 min. movies.

Of course i realise its also content specific, ie. action, romance movie etc. but is what im saying generally true?

[Hiro2k]

It depends on the movie and how well it compresses. If you encode with Gknot, try to do a compressibility test. You will see that some movies need alot of bitrate (Anime) and some do not. Also activating B Frames in the Pro Version will help compress the movie even more. I just yesterday ripped "From Hell" 122 Mins. The movie is dark and it had 100% quality with a bitrate of 548. The bottom line is that it depends on your source. And if you are willing to sacrifice some video size, you can get it to fit on 1 CD and still look good.

[NeVeRLiFt]

I use between 700-900 and my 1cd rips look very good.
Some scenes or even the whole movie may need higher bitrate.
If a movie has water, fire are lots of fast motion then it can always use the higher bitrate, if the movie is dark that helps.
Also I guess if the DVD itself is not the best source, like some DVD's of older movies.

[geocapital]

I ripped the Planet of Apes and tried from 1000 to 2500 bitrate with 5.0.2.
At all cases, it was only 620MB. Since max quality for the resolution I used (504*240- I don't recall exactly - the movie is has 2,34:1 aspect though) was reached at the first case, the encoder did not use more that 1000 (or less) for the movie. And it is around 115 minutes.

What I do now is using 2500 and I let the encoder get the max of quality, whatever the MB of the movie, finally, are.

Also, I have found that the limit for my movies to look find is a resolution around 500*sth, and it usually fits one CD.

[DJ Bobo]

@ geocapital
Havn't you seen an option called "1-pass quality based"?! -.-
You set this to 100% and you'll get the maximum quality you can get with the codec -.-

[geocapital]

DJ Bobo,

If in that way you get the maximum quality, then what's the need to do a double pass?

I thought it was the quality proportional to that of the original avi.
So, if you set it to 50% you will get an avi with "half" the quality of the original one.

But if you are sure of it, then ok.

[Mac Sidewinder]

There is no need for a double pass if you use 100% single pass to achieve max quality. The reason for a double pass is to distribute the bits to best encode the dvd in a limited filesize/bitrate. If you set no limit to the filesize or bitrate then by all means use a single pass. It will save you tons of time.

Mac

[geocapital]

I don't disagree.

However, my first statement was that with a double pass at eg.2000 bitrate and resolution of 500+sth*sth,
I usually get the max quality + the avi fits in 1CD.
With 1-pass, it might not fit.

Anyway, I tought something out of this discussion.

See you around.

[Mac Sidewinder]

If you are using a high enough bitrate to "max" out the encode with 2 pass then it will be the same size as a 1 pass 100% encode. It wouldn't matter if you put 10000 for the bitrate, it would be the same size maxed out. My point was that if you wanted 100% quality then it makes no sense to do a 2 pass encode (imho)

Mac

[DJ Bobo]

@ Mac Sidewinder
Not IMHO, it's true! ;)

@ geocapital
Try it and see for yourself, there is nothing I can tell you more! well, may be one thing, quality based 50% or 0 or 100% has no relation with the original AVI or MPEG file, every percentage will encode the movie at a constant quantizer. 50% means: encode the whole movie with a fixed quantizer of 16.6 and it will look like shit, no matter how good the original file looks like!
100% means the whole movie will be encoded at quantizer 2, which means optimal quality all the way.

As said, try it and see for yourself! 2-pass (at an exactly calculated bitrate!) is only usefull when you wanna fit a given size! any other variation is a waste of time and won't bring anything in matters of quality!

[ChannelK]

I went to experient with 1 pass quality based via virtual dub, but i keep getting an avsynth access violation error, this (appart from a string of numbers) is all i can give, any ideas?

[geocapital]

When it happens to me, I just do it again. Usually it goes ok.

[DJ Bobo]

@ channelk
You have somewhere an error in your avisynth script. This has nothing to do, with you having chosen "1-pass quality based" or not.

[ChannelK]

strangely enough, the error constistantly occurs with 1 pass quality based, but never for 2 passes.

[DJ Bobo]

Well, that's a new one, never happened to me.
Can you post you avs file for us to see?
Which versions are you using? (I'm using AVS 1.05 & VD 1.4.10)

[BrainBug]

Originally posted by geocapital
I don't disagree.

However, my first statement was that with a double pass at eg.2000 bitrate and resolution of 500+sth*sth,
I usually get the max quality + the avi fits in 1CD.
With 1-pass, it might not fit.

Anyway, I tought something out of this discussion.

See you around.

@Geocapital
U use a Bitrate at 2000 (in 2pass encoding) with a resolution of 500x* and the final avi is fit in 1 cd??????????????......:eek:
all of these is in GKnot/Vdub encoding?

[DJ Bobo]

@ brainbug
Of course it never reaches 2000 average! it is already saturated somewhere under 1000kbps, but he is (was?) not aware of this.

[geocapital]

I knew it was not reaching 2000 bitrate.
But in this way, I think that I could get the best for each scene.
A low bitrate for a slow scene and a higher for a fast. Never 2000, cause I checked it. The movie encoded from 1200 to 2500 bitrate was the same MB.

Maybe it's the same with 1-pass quality. However, this worked only for the planet of apes. The other movies that I did needed around 850 to fit in the cd.

What I never understood was why two encodings, having every setting the same, sometimes had different image quality.

[geocapital]

By the way, when i encode a movie at 600* and make it fit in 1cd, I see macroblocks while on full screen.
This does not happen when I use 500* resolution and fit it in 1cd. The image is perfect, usually only on full screen (1024*)
I suppose because it gives more space to each pixel, so the image is smoother.

However, I saw some people saying that they never encode to lower than 600* and fits in 1cd and it is ok. Ok in full screen, or in 600*?
That was a question I always had, but never searched for an answer.