On Wed, Feb 12, 2014 at 02:14:01PM +0100, Niels Möller wrote: > Christophe Gisquet <[email protected]> writes: > > > Are you sure it's not just a convenience to output the more practical, > > aligned 24bits? Like something in the bitstream actually indicating > > "shift left 4 bits", and the audio is *actually* 20 bits? > > My inderstanding is that it really is 20 bit samples, shifted left to > fill 24-bits. From page 142 of the spec (close to the end of the section > on the XLL lossless extension): > > To obtain the output words, the resulting samples still need to be > shifted left by NumEmptyLSBs places. > > I haven't really digested the spec yet, but I think the least > significant bits are transmitted without compression. Which makes sense, > since they ought to be pretty close to white noise, which is > uncompressible by any lossless algorithm.
IIRC there's even a picture later about MSB and LSB recombining. _______________________________________________ libav-devel mailing list [email protected] https://lists.libav.org/mailman/listinfo/libav-devel
