[XviD-devel] Dev-API-4 : Possibility to mark a defined area of the encoded picture as 'BLACK=0' , to encode BlackBars with absolute minimum of bitrate ?

trbarry at trbarry.com trbarry at trbarry.com
Sun Jul 27 09:33:08 CEST 2003


| On the other hand, completely black macroblocks are processed
| very fast
| in ME and marked as SKIP. So if avisynth or whatever
| application creates
| the black bars, XviD slows down only a little.

Since black in NTSC is not usually zero, what actual "black" YV12 values
are recognized to qualify these macroblocks to be skipped? Any idea if
it corresponds to the actual black bars found on DVD's or generated by
the Avisynth AddBorders() function, etc?

- Tom

| -----Original Message-----
| From: xvid-devel-bounces at xvid.org
| [mailto:xvid-devel-bounces at xvid.org]On
| Behalf Of Christoph Lampert
| Sent: Sunday, July 27, 2003 5:46 AM
| To: xvid-devel at xvid.org
| Subject: Re: [XviD-devel] Dev-API-4 : Possibility to mark a
| defined area
| of the encoded picture as 'BLACK=0' , to encode BlackBars
| with absolute
| minimum of bitrate ?
|
|
| On Sun, 27 Jul 2003, ChristianHJW wrote:
|
| >
| > Hi,
| >
| > sorry if i am too dumb to look this up from the specs, but does
| > dev-api-4 allow apps to tell XviD to set certain areas of
| the picture
| > internally to 'BLACK', such that these macroblocks are just
| written as
| > '0' from the encoder ?
|
| No, that's not part of dev-api-4.
| I though about it, too, a while ago, but adding such a feature to not
| encode certain regions would need very big internal changes: At the
| moment, all macroblock loops start at 0 and run till the end of the
| picture. Those would have to be change to start and stop at arbitrary
| positions and special cases would have to be added to treat
| the remaining
| blocks.
| That doesn't sound like much work, but since these loops are
| spread over
| all files, it would surely produce some unwanted side effects and new
| bugs...
| On the other hand, completely black macroblocks are processed
| very fast
| in ME and marked as SKIP. So if avisynth or whatever
| application creates
| the black bars, XviD slows down only a little.
|
| gruel
|
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| XviD-devel at xvid.org
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