maybe an idea for upcoming xvid-versions

[olnima]

Wouldn't it be nice to have a kind of a "limiter" for Quantizer-Mode?
When using Quantizer "x" You'll never know how the filesize will be. If there would be a limiter I still wouldn't know the final filesize but I would the know MAXIMUM filesize to be sure that the resulting avi fits on a cd or on the remaining space on a DVD.

Just a thought...

Greetz,
Olnima

[Koepi]

Nice suggestion, but don't you think it would be there if it were possible?

Fixed quant at fixed size in single pass contradict so much that it even causes my brain to hurt when thinking about it :)

(So now you know why 2 pass was invented at all.)

Regards
Koepi

[RadicalEd]

Hm... a cut-off could be implemented though, couldn't it? It should be possible to calculate the max frame size allowed from a set maximum bitrate, and then any frame over that limit could be re-quantized until it's below the limit. Is that possible to do during 1 pass encoding? A cap would be useful for standalones and some level compliancy, even if max bitrate is only one of the dozen parameters that have to be met for that.
But, again, I'm not sure if that's feasible during a single pass.

[Koepi]

Well, you suggest to enable rate control to reencode a frame several times until it hits target size - but rate control on 1 pass does already something like this, but with a delay (reaction delay factor).

Nothing revolutionary, and it still has nothing to do with fixed quant.
At fixed quant a frame has a fixed size, no matter how often you run the quantization routines over it ;)

Regards
Koepi

[olnima]

If it's not possible -> it's not possible... :D
As I wrote: just a thought.

Thanks anyway
Olnima

[RadicalEd]

Originally posted by Koepi
Well, you suggest to enable rate control to reencode a frame several times until it hits target size - but rate control on 1 pass does already something like this, but with a delay (reaction delay factor).

Nothing revolutionary, and it still has nothing to do with fixed quant.
At fixed quant a frame has a fixed size, no matter how often you run the quantization routines over it ;)

Regards
Koepi

Duh, I forgot we were talking about fixed quant. I was thinking raising the q until you're under the limit.. but that wouldn't be very fixed at all :|

I need to take a closer look at plugin_single.c now ;)