Trying to get the filesize of a video up

CaTaClYsM · Post by **CaTaClYsM** » Sat Apr 05, 2003 2:47 am

Well I was backing up a DVD and I was using the XVID guide on Doom9.org (just to see what it was like. I have no real need to.) and a funny thing happened.

The file was about 613 megs (for the audio and video) , the CD's I have are 700. So I decided to try and get the movie a bit bigger to fit the size of the DVD. I did several 2 pass encodes and they never got bigger than 604 megs. Eventually I said 'screw it' and did single pass CBR encodes. Heres the funny part. I did a 6500 7500 8500 and 9000 bitrate encodes all within megabytes of each other. The size increase went from 633 at 6500 to 634 at 9000. Anyone know why that is?

trythil · Post by **trythil** » Sat Apr 05, 2003 3:10 am

CaTaClYsM wrote:Well I was backing up a DVD and I was using the XVID guide on Doom9.org (just to see what it was like. I have no real need to.) and a funny thing happened.

The file was about 613 megs (for the audio and video) , the CD's I have are 700. So I decided to try and get the movie a bit bigger to fit the size of the DVD. I did several 2 pass encodes and they never got bigger than 604 megs. Eventually I said 'screw it' and did single pass CBR encodes. Heres the funny part. I did a 6500 7500 8500 and 9000 bitrate encodes all within megabytes of each other. The size increase went from 633 at 6500 to 634 at 9000. Anyone know why that is?

Because the bitrate you set does not have a linear correlation to the final file size. If you were to plot encode size as a function of bitrate for a particular data set, you'd probably find it to loosely resemble an exponential curve that is asymptotic to some encode size. (Note "loosely resemble", as I doubt that the function would be exponential in nature, not knowing enough about the specific transforms involved.)

Most likely, the encoder simply isn't finding any more data to work with, or at least, any more data of consequence.

Filling up 634 / 700 megabytes should be good enough...

the Black Monarch · Post by **the Black Monarch** » Sat Apr 05, 2003 4:45 am

You could always increase the filesize by simply not compressing it, but I think that would give you a completely different and much worse problem...

Zarxrax · Post by **Zarxrax** » Sat Apr 05, 2003 12:13 pm

The codec is maxed out, it has achieved all it can achieve. Try changing the quantizer type to MPEG instead of H.236. If you are using B-frames, disable them. If neither of those can help, under the quantizer tab, allow it to use quantizer 1.

AbsoluteDestiny · Post by **AbsoluteDestiny** » Sat Apr 05, 2003 12:26 pm

CaTaClYsM wrote:The size increase went from 633 at 6500 to 634 at 9000. Anyone know why that is?

It will only use the full bitrate if the scene needs that many bits.

What you have is maximum quality at those settings - there is no way of making it bigger without:

1) higher resolution

2) quantizer 1

3) turning off space saving options such as b-frames, gcm, qpel lumi masking etc etc

In short, don't complain... it's as nice looking as you are going to get.

CaTaClYsM · Post by **CaTaClYsM** » Sat Apr 05, 2003 1:28 pm

Time to UP THE RESOLUTION!

AnimeMusicVideos.org

Trying to get the filesize of a video up

Trying to get the filesize of a video up

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Re: Trying to get the filesize of a video up