[XviD-devel] multiple reference frames

[suxen_drol]

On Mon, 31 Mar 2003 17:02:34 +0200 Nicolas Dumoulin <news at bobuse.fr.st> wrote:
> yop,

that would be "yo"

> In the fonction encoder_encode(...) (decoder.c), there is the line :
> SWAP(pEnc->current, pEnc->reference);
> So I think it's the place where I could intervene to encode a P-Frame 
> with a choosen reference frame. Is it ?

yes, but, xvid only stores the last reference frame. so you if you wish
to experiment with multiple reference frames, you will need to add an 
additional buffer to store all the references frames.

note: multiple refernce frames will break mpeg-4 compatiblity with
simple and advanced-simple profiles. the advanced-realtime-simple
supports multiple reference frames, however this profile is not widely
supported by commerical decoders.

> In order to could use reference frame in the next of the sequence, I 
> would first encode all the I-Frame, and then work with the P-Frame. I've 
> looked the file xvid_stat.c, and I think it's possible to modify the 
> main loop.

i dont fully understand what you are saying.

to support multiple reference frames you will, at the very mimimum, need
to modify the Encoder struct (encoder.h), and the encoder_encoder()
function (encoder.c).

-- pete