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near lossless: fix unsigned int overflow warnings.

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Change-Id: Ic1111a66761b5821cbbea1c91b038b2327dd20b5
This commit is contained in:
Vincent Rabaud 2017-05-22 15:52:33 +02:00
parent 972104b34b
commit 9bbc0891c6
2 changed files with 11 additions and 7 deletions
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13
src/enc/predictor_enc.c
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@ -180,6 +180,8 @@ static uint8_t NearLosslessComponent(uint8_t value, uint8_t predict,
// max_quantization which is a power of 2, smaller than max_diff). Take care if // max_quantization which is a power of 2, smaller than max_diff). Take care if
// value and predict have undergone subtract green, which means that red and // value and predict have undergone subtract green, which means that red and
// blue are represented as offsets from green. // blue are represented as offsets from green.
#define NEAR_LOSSLESS_DIFF(a, b) \
(uint8_t)((((int)((a) >> 16) - (int)(b))) & 0xff)
static uint32_t NearLossless(uint32_t value, uint32_t predict, static uint32_t NearLossless(uint32_t value, uint32_t predict,
int max_quantization, int max_diff, int max_quantization, int max_diff,
int used_subtract_green) { int used_subtract_green) {
@ -196,7 +198,7 @@ static uint32_t NearLossless(uint32_t value, uint32_t predict,
} }
if ((value >> 24) == 0 || (value >> 24) == 0xff) { if ((value >> 24) == 0 || (value >> 24) == 0xff) {
// Preserve transparency of fully transparent or fully opaque pixels. // Preserve transparency of fully transparent or fully opaque pixels.
a = ((value >> 24) - (predict >> 24)) & 0xff; a = NEAR_LOSSLESS_DIFF(value >> 24, predict >> 24);
} else { } else {
a = NearLosslessComponent(value >> 24, predict >> 24, 0xff, quantization); a = NearLosslessComponent(value >> 24, predict >> 24, 0xff, quantization);
} }
@ -209,15 +211,16 @@ static uint32_t NearLossless(uint32_t value, uint32_t predict,
// The amount by which green has been adjusted during quantization. It is // The amount by which green has been adjusted during quantization. It is
// subtracted from red and blue for compensation, to avoid accumulating two // subtracted from red and blue for compensation, to avoid accumulating two
// quantization errors in them. // quantization errors in them.
green_diff = (new_green - (value >> 8)) & 0xff; green_diff = NEAR_LOSSLESS_DIFF(new_green, value >> 8);
} }
r = NearLosslessComponent(((value >> 16) - green_diff) & 0xff, r = NearLosslessComponent(NEAR_LOSSLESS_DIFF(value >> 16, green_diff),
(predict >> 16) & 0xff, 0xff - new_green, (predict >> 16) & 0xff, 0xff - new_green,
quantization); quantization);
b = NearLosslessComponent((value - green_diff) & 0xff, predict & 0xff, b = NearLosslessComponent(NEAR_LOSSLESS_DIFF(value, green_diff),
0xff - new_green, quantization); predict & 0xff, 0xff - new_green, quantization);
return ((uint32_t)a << 24) | ((uint32_t)r << 16) | ((uint32_t)g << 8) | b; return ((uint32_t)a << 24) | ((uint32_t)r << 16) | ((uint32_t)g << 8) | b;
} }
#undef NEAR_LOSSLESS_DIFF
// Stores the difference between the pixel and its prediction in "out". // Stores the difference between the pixel and its prediction in "out".
// In case of a lossy encoding, updates the source image to avoid propagating // In case of a lossy encoding, updates the source image to avoid propagating

5
src/enc/vp8l_enc.c
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@ -1261,12 +1261,13 @@ static WEBP_INLINE uint32_t ApplyPaletteHash0(uint32_t color) {
static WEBP_INLINE uint32_t ApplyPaletteHash1(uint32_t color) { static WEBP_INLINE uint32_t ApplyPaletteHash1(uint32_t color) {
// Forget about alpha. // Forget about alpha.
return ((color & 0x00ffffffu) * 4222244071u) >> (32 - PALETTE_INV_SIZE_BITS); return ((uint32_t)((color & 0x00ffffffu) * 4222244071ull)) >>
(32 - PALETTE_INV_SIZE_BITS);
} }
static WEBP_INLINE uint32_t ApplyPaletteHash2(uint32_t color) { static WEBP_INLINE uint32_t ApplyPaletteHash2(uint32_t color) {
// Forget about alpha. // Forget about alpha.
return (color & 0x00ffffffu) * ((1u << 31) - 1) >> return ((uint32_t)((color & 0x00ffffffu) * ((1ull << 31) - 1))) >>
(32 - PALETTE_INV_SIZE_BITS); (32 - PALETTE_INV_SIZE_BITS);
} }