Re: HDF5 bitfields...

Hi John,

> >>If we have the ability to store variable length "compressed formats", 
> >>then it seems like we can define some simple format for this, say a sequence
> >>
> >>  n  (int)
> >>  nbits (byte)
> >>  scale (float/double)
> >>  offset (float/double)
> >>  n nbit integers
> >>
> >>so that the compressed data is self contained, with no need for auxilary 
> >>variables or info stored outside the chunk.
> >>    
> >>
> >    I thought you wanted the predefined scale/offset values to vary according
> >to the chunk's location in the dataspace?
> >  
> >
> The above format would describe the compressed data format for one 
> chunk. So the scale, offset could vary for each chunk.
> 
> I was proposing that we start with the case where the scale and offset 
> are automatically calculated by the compression filter. I think that 
> will be the most common case.
> 
> Not sure if im missing something.
    This is fine for the "adaptive" case, but it's not sufficient for the
"predefined" scale/offset that varies according to the coordinates of the
chunk.  If that's OK for now, then we won't have a problem.

    Quincey