| Message ID | 20181219220003.27225-2-matthew.w.fearnley@gmail.com |
|---|---|
| State | New |
| Headers | show |
ons 2018-12-19 klockan 22:00 +0000 skrev matthew.w.fearnley@gmail.com: > > From: Matthew Fearnley <matthew.w.fearnley@gmail.com> > > Store the value of *xored computed within block_cmp() in a local variable, > and only update the *xored parameter at the same time as *mx,*my are set. > This ensures that the value of *xored is accurate for the value of *mx,*my > whenever the function ends. > > Note that the local variable is not needed in the intial block_cmp for (0,0) > because *mx,*my and *xored are all set there. > > The previous logic worked by exiting early if ever !*xored, but put implicit > requirements on block_cmp() to: > - always return 0 if !xored > - never return a negative value > --- > libavcodec/zmbvenc.c | 4 +++- Looks good /Tomas
diff --git a/libavcodec/zmbvenc.c b/libavcodec/zmbvenc.c index 2f041dae32..0e8ee5ce31 100644 --- a/libavcodec/zmbvenc.c +++ b/libavcodec/zmbvenc.c @@ -100,6 +100,7 @@ static int zmbv_me(ZmbvEncContext *c, uint8_t *src, int sstride, uint8_t *prev, int pstride, int x, int y, int *mx, int *my, int *xored) { int dx, dy, tx, ty, tv, bv, bw, bh; + int txored; *mx = *my = 0; bw = FFMIN(ZMBV_BLOCK, c->avctx->width - x); @@ -111,11 +112,12 @@ static int zmbv_me(ZmbvEncContext *c, uint8_t *src, int sstride, uint8_t *prev, if(tx == x && ty == y) continue; // we already tested this block dx = tx - x; dy = ty - y; - tv = block_cmp(c, src, sstride, prev + dx + dy * pstride, pstride, bw, bh, xored); + tv = block_cmp(c, src, sstride, prev + dx + dy * pstride, pstride, bw, bh, &txored); if(tv < bv){ bv = tv; *mx = dx; *my = dy; + *xored = txored; if(!bv) return 0; } }
From: Matthew Fearnley <matthew.w.fearnley@gmail.com> Store the value of *xored computed within block_cmp() in a local variable, and only update the *xored parameter at the same time as *mx,*my are set. This ensures that the value of *xored is accurate for the value of *mx,*my whenever the function ends. Note that the local variable is not needed in the intial block_cmp for (0,0) because *mx,*my and *xored are all set there. The previous logic worked by exiting early if ever !*xored, but put implicit requirements on block_cmp() to: - always return 0 if !xored - never return a negative value --- libavcodec/zmbvenc.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)