[FFmpeg-devel] [PATCH] Electronic Arts TGV decoder

[pross at xvid.org]

On Sat, Jul 19, 2008 at 11:30:38AM +0200, Reimar D?ffinger wrote:
> Hello,
> >  /**
> > - * \brief copy previously decoded bytes to current position
> > - * \param back how many bytes back we start
> > + * \brief deliberate overlapping memcpy implementation
> > + * \param dst destination buffer; must be padded by 12 bytes
> > + * \param back how many bytes back we start (the initial size of the overlapping window)
> >   * \param cnt number of bytes to copy, must be >= 0
> >   *
> >   * cnt > back is valid, this will copy the bytes we just copied,
> >   * thus creating a repeating pattern with a period length of back.
> >   */
> > -static inline void copy_backptr(LZOContext *c, int back, int cnt) {
> > -    register const uint8_t *src = &c->out[-back];
> > -    register uint8_t *dst = c->out;
> > -    if (src < c->out_start || src > dst) {
> > -        c->error |= LZO_INVALID_BACKPTR;
> > -        return;
> > -    }
> > -    if (cnt > c->out_end - dst) {
> > -        cnt = FFMAX(c->out_end - dst, 0);
> > -        c->error |= LZO_OUTPUT_FULL;
> > -    }
> > +void av_memcpy_backptr(uint8_t *dst, int back, int cnt) {
> > +    const uint8_t *src = dst-back;
> >      if (back == 1) {
> >          memset(dst, *src, cnt);
> >          dst += cnt;
> > @@ -157,10 +149,32 @@
> >          }
> >          dst += cnt;
> >      }
> > -    c->out = dst;
> >  }
> >  
> >  /**
> > + * \brief copy previously decoded bytes to current position
> > + * \param back how many bytes back we start
> > + * \param cnt number of bytes to copy, must be >= 0
> > + *
> > + * cnt > back is valid, this will copy the bytes we just copied,
> > + * thus creating a repeating pattern with a period length of back.
> > + */
> > +static inline void copy_backptr(LZOContext *c, int back, int cnt) {
> 
> The diff should be smaller if you change the order of these two
> functions.

Okay, but s/smaller/simpler/.

Updated patch enclosed, addressing your request, and Michael's final
comments.

-- Peter
(A907 E02F A6E5 0CD2 34CD 20D2 6760 79C5 AC40 DD6B)
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