[XviD-devel] [Fwd: Data partitioning for encoder]

[sigdrak]

Bonsoir/Good evening,

Skal wrote:
> 	Anyway, this step toward data partitioning raises few questions:
> 	a) we'll have to add DP support in decoder too, sure. Or people
> 	won't understand a file created with XviD... can't be played with
> 	XviD.

Indeed, as with time tools may expose such a feature. But then, most 
users, except with streaming in error-prone environments in mind, will 
have no use for such a feature. As for video packets and reversible VLCs 
in fact.

But to quote my very unclear self:
"I have decoder-side pending code, but unfortunately, it is merged with 
my current work on video packetization."
I could extract the decoder part of DP, as it should only be in 
decoder.c and no video packets should interfere with it. Actually, the 
decoder already handles video packets.

> 	b) What about reversible VLCs?

This is indeed the next thing in DP. But they aren't mandatory. For now, 
the bitstream signals that they are not in use at the VOP level. I 
believe it's a part that requires a bit more work actually:
. reversible VLC tables are not used for B frames
. the escape coding is different
So I'd prefer implementing first video packets in the encoder.

In fact, what I really see as missing is error concealment. As far as I 
can see, XviD has none, and nothing has been designed for it.