[Ffmpeg-devel] [PATCH] simple internal lzo decoder

[Reimar Döffinger]

Hi,
On Sat, Jan 14, 2006 at 06:07:04PM +0100, Michael Niedermayer wrote:
> On Sat, Jan 14, 2006 at 04:21:44PM +0100, Reimar D?ffinger wrote:
> [...]
> > -    do {
> > -        *c->out++ = c->out[-back];
> > -    } while (--cnt);
> > +    if (back == 1)
> > +        memset(c->out, c->out[-1], cnt);
> > +    else {
> > +        int blocklen = (cnt > back) ? back : cnt;
> > +        uint8_t *start = &c->out[-back];
> > +        while (cnt > blocklen) {
> > +           memcpy(c->out, start, blocklen);
> > +           c->out += blocklen;
> > +           cnt -= blocklen;
> > +           blocklen <<= 1;
> > +        }
> > +        memcpy(c->out, start, cnt);
> > +    }
> > +    c->out += cnt;
> 
> is that faster then memmove()?

This is not what memmove does, memmove will actually do "the opposite"
by specifically starting to write at the end (as to not overwrite the to
be copied part).

Greetings,
Reimar D?ffinger