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WebP-Lossless encoding improvements.

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Lossy (with Alpha) image compression gets 2.3X speedup.
Compressing lossless images is 20%-40% faster now.

Change-Id: I41f0225838b48ae5c60b1effd1b0de72fecb3ae6
This commit is contained in:
Vikas Arora
2013-05-08 17:19:04 -07:00
parent 4cb234d5b5
commit 8eae188a62
6 changed files with 159 additions and 94 deletions
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21
src/dsp/lossless.c
View File

@ -1325,6 +1325,27 @@ void VP8LConvertFromBGRA(const uint32_t* const in_data, int num_pixels,
}
}
// Bundles multiple (1, 2, 4 or 8) pixels into a single pixel.
void VP8LBundleColorMap(const uint8_t* const row, int width,
int xbits, uint32_t* const dst) {
int x;
if (xbits > 0) {
const int bit_depth = 1 << (3 - xbits);
const int mask = (1 << xbits) - 1;
uint32_t code = 0xff000000;
for (x = 0; x < width; ++x) {
const int xsub = x & mask;
if (xsub == 0) {
code = 0xff000000;
}
code |= row[x] << (8 + bit_depth * xsub);
dst[x >> xbits] = code;
}
} else {
for (x = 0; x < width; ++x) dst[x] = 0xff000000 | (row[x] << 8);
}
}
//------------------------------------------------------------------------------
#if defined(__cplusplus) || defined(c_plusplus)

3
src/dsp/lossless.h
View File

@ -83,6 +83,9 @@ static WEBP_INLINE uint32_t VP8LSubPixels(uint32_t a, uint32_t b) {
return (alpha_and_green & 0xff00ff00u) | (red_and_blue & 0x00ff00ffu);
}
void VP8LBundleColorMap(const uint8_t* const row, int width,
int xbits, uint32_t* const dst);
//------------------------------------------------------------------------------
#if defined(__cplusplus) || defined(c_plusplus)