[x264-devel] Custom slice support

[List, Peter]

> From: Mojtaba Hosseini [mailto:Mojtaba.Hosseini at magorcorp.com]
> On Wed, 2007-11-14 at 13:23 +0100, List, Peter wrote:
> 
> > Yes, it does, but only if you HAVE ACTIVATED SLICES, which is not
> > supported anymore.
> >
>   Hello Peter,
> You are right.
> I was referring to my patch. With the patch, you can activate slices
> if you want, in which case slice headers come before every NAL and
> prediction between slices is not done.

Dear Mojtaba,
I'm sorry; it seems I don't really get it...
How do you guarantee that "prediction between slices is not done"
(Mojtaba) when "Current x264 doesn't support slices at all" (Loren)

How is this patch working...
The process starts with x264 producing macroblocks until one packet is 
full, right? Than your patch produces a slice header and completes one
NALU.
If x264 then continues, how does it know that it needs to produce a new
slice? Does the x264code still have all the necessary variables and
methods to obey the H264 slice restrictions, so that your patch can
feedback the fact, that a new slice is to be coded into the original
x264 code? 
If that is true what else could we want?? Why is Loren saying then:

>> Current x264 doesn't support slices at all. It will support
horizontal 
>> slices when I get around to merging that patch. 

> You are correct that if the first NAL is lost and frame level
> information has changed, the subsequent NALs can't be decoded
> properly. In this case, perhaps you could augment the patch with
> insertion of frame level headers before every NAL?

What are frame level headers? There are only slice headers in H.264
...and you say yourself:
> With the patch, you can activate slices if you want, in which 
> case slice headers come before every NAL
If that is true, we have no problem, because slice headers (at least
H264-slice headers) DO HAVE all the information in them we need. 

>    The original point was that, with the help of people on this list,
> there is a patch that tries to bring back splitting of frame into
NALs.
> If you are using such a feature, then you may want to try the patch
> and help make it better or more complete.

To me that only makes sense if a NALU is equivalent to a slice in the
H264-definition (or multiple complete slices, or parts of slices, that
become complete with multiple complete NALU's).
Is that the case??? 


 
> Mojtaba Hosseini
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