[XviD-devel] 2pass credits - draft 2

[suxen_drol]

On Fri, 11 Apr 2003 22:19:14 +1000 suxen_drol <suxen_drol at hotmail.com> wrote:
> On Thu, 10 Apr 2003 21:42:08 +1000 suxen_drol <suxen_drol at hotmail.com> wrote:
> > hi,
> > 
> > anyone got anyideas what to do with credits in 2pass?
> > my ideas are pretty lame,

ive thought about it futher:

we should have *one* target bitrate slider (as opposed to many) and let
the user specifiy a 'forced quantizer' or 'desired quality ratio' for
each section.

when encoding, xvid will scale the bitrate/2pass-frame-size by the
desired quality, whilst maintaining the target bitrate.
for example, in during [80000,82000) we'd allocate 30% more bits.

> +---------------------------------------+
> |                                       |
> | Profile         [AS at L1        ] [..]  |
> | RC mode:        [Twopass-2    ] [..]  |
> | Target (kbps):  [708          ]       |
> |                 |----*--------|       |
> |                                       |
> | --frames-----mult(q)------ flags---AA |
> | |      0       (5)          +G     || |
> | |    260       100                 || |
> | |  80000       130                 || |
> | |  82000       100                 || |
> | | 125000       (5)          +G     || |
> | |                                  || |
> | |                                  || |
> | -----------------------------------VV |
> | [Add] [Remove]               [Edit]   |
> |                                       |
> |          [ Advanced... ]              |
> |          [Load defaults]              |
> |          [    OK       ]              |
> +---------------------------------------+

any one with comments, suggestions?
e.g. should we stick to decimal "100" "130", or 
use floats like "1.0" "1.3" ?

-- pete