[FFmpeg-devel] Fwd: [PATCH] Psygnosis YOP demuxer

[Reimar Döffinger]

On Sat, Mar 27, 2010 at 10:57:30PM +0530, Mohamed Naufal wrote:
> On 27 March 2010 22:37, Reimar D?ffinger <Reimar.Doeffinger at gmx.de> wrote:
> > Btw. (I'm not asking you to implement it) you could probably gain quite
> > some speed by using a "tighter" loop for the middle part of the frame that
> > does not do this check and the dstptr - dstbuf check, and thanks to padding
> > the srcptr check could be done much more rarely there as well.
> 
> 
> But wouldn't that entail further checks? Please elaborate.

Checks that you are "in the middle of the frame", yes.
But it's sufficient to do that check e.g. only after each 8
bytes decoded.
So you could decode 8 bytes in a row without any checks, then
do all the checks necessary and then either continue with the
"fast" code or switch to the "careful" code.
Yes, you will have more checks, but those checks will be executed
only 1/8th as often.