dany/libwebp
1
0
Fork 0
mirror of https://github.com/webmproject/libwebp.git synced 2025-07-15 21:39:59 +02:00
Code Issues Actions Packages Projects Releases Wiki Activity

simplify the main loop for downscaling

Browse Source 
(part of bug #254 investigation)

no speed change observed.

Change-Id: Ie21b33171def367f37643fef6a0bd378e49468c7
This commit is contained in:
Pascal Massimino
2015-08-03 16:49:00 +02:00
parent 585d93dbba
commit c455676680
4 changed files with 9 additions and 8 deletions
Download Patch File Download Diff File Expand all files Collapse all files

11
src/dsp/rescaler.c
View File

@ -28,16 +28,17 @@ static void RescalerImportRowC(WebPRescaler* const wrk,
if (!wrk->x_expand) {
int sum = 0;
for (x_out = channel; x_out < x_out_max; x_out += x_stride) {
uint32_t base = 0;
accum += wrk->x_add;
for (; accum > 0; accum -= wrk->x_sub) {
sum += src[x_in];
while (accum > 0) {
accum -= wrk->x_sub;
base = src[x_in];
sum += base;
x_in += x_stride;
}
{ // Emit next horizontal pixel.
const int32_t base = src[x_in];
const int32_t frac = base * (-accum);
x_in += x_stride;
wrk->frow[x_out] = (sum + base) * wrk->x_sub - frac;
wrk->frow[x_out] = sum * wrk->x_sub - frac;
// fresh fractional start for next pixel
sum = (int)MULT_FIX(frac, wrk->fx_scale);
}