[Mplayer-cvslog] CVS: main/DOCS/tech mpcf.txt,1.7,1.8

[Andreas Hess]

On Fri, Feb 07, 2003 at 02:44:27PM +0100, Michael Niedermayer wrote:
> On Friday 07 February 2003 13:57, Andreas Hess wrote:
> > And what about no checksum at all in plain frames, allowing the
> > checksum (or frame_checksum) just in keyframes, and there the
> > checksum is the checksum (or frame_checksum) over all previous
> > frames.
> hmm if only the keyframes contain the checksum, then each keyframe would 
> contain the checksum for the previous frames ...
> the last frames after the last keyframe would have no checksum
> and if we cut the stream at a keyaframe than its checksum would cover frames 
> which are no longer there, this seems bad, so IMHO the current way of 
> requireing the checksum to be in the last frame before a keyframe (or more 
> often) is better 

Ok, I see, but what about making the checksum forward calculated?

And the checksum, over what part is it calculated, over the header,
the payload or over the whole frame? Maybe it would just be enough
to calculate the checksum over the headers to guarantee, that the
structure of the file itself is ok, and leave the correctness of
the payload to the respective codecs.


Andreas