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Copy C code to not have multiplication overflow

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Change-Id: I9375170ce1217921a334c5b93dc3e0084f976688
This commit is contained in:
Vincent Rabaud
2024-03-05 11:33:59 +01:00
parent 1fb9f3dcf1
commit 501d9274a7
12 changed files with 109 additions and 126 deletions
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21
src/dsp/enc.c
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@@ -109,10 +109,6 @@ static WEBP_TSAN_IGNORE_FUNCTION void InitTables(void) {
#define STORE(x, y, v) \
dst[(x) + (y) * BPS] = clip_8b(ref[(x) + (y) * BPS] + ((v) >> 3))
static const int kC1 = 20091 + (1 << 16);
static const int kC2 = 35468;
#define MUL(a, b) (((a) * (b)) >> 16)
static WEBP_INLINE void ITransformOne(const uint8_t* ref, const int16_t* in,
uint8_t* dst) {
int C[4 * 4], *tmp;
@@ -121,8 +117,10 @@ static WEBP_INLINE void ITransformOne(const uint8_t* ref, const int16_t* in,
for (i = 0; i < 4; ++i) { // vertical pass
const int a = in[0] + in[8];
const int b = in[0] - in[8];
const int c = MUL(in[4], kC2) - MUL(in[12], kC1);
const int d = MUL(in[4], kC1) + MUL(in[12], kC2);
const int c =
WEBP_TRANSFORM_AC3_MUL2(in[4]) - WEBP_TRANSFORM_AC3_MUL1(in[12]);
const int d =
WEBP_TRANSFORM_AC3_MUL1(in[4]) + WEBP_TRANSFORM_AC3_MUL2(in[12]);
tmp[0] = a + d;
tmp[1] = b + c;
tmp[2] = b - c;
@@ -134,10 +132,12 @@ static WEBP_INLINE void ITransformOne(const uint8_t* ref, const int16_t* in,
tmp = C;
for (i = 0; i < 4; ++i) { // horizontal pass
const int dc = tmp[0] + 4;
const int a = dc + tmp[8];
const int b = dc - tmp[8];
const int c = MUL(tmp[4], kC2) - MUL(tmp[12], kC1);
const int d = MUL(tmp[4], kC1) + MUL(tmp[12], kC2);
const int a = dc + tmp[8];
const int b = dc - tmp[8];
const int c =
WEBP_TRANSFORM_AC3_MUL2(tmp[4]) - WEBP_TRANSFORM_AC3_MUL1(tmp[12]);
const int d =
WEBP_TRANSFORM_AC3_MUL1(tmp[4]) + WEBP_TRANSFORM_AC3_MUL2(tmp[12]);
STORE(0, i, a + d);
STORE(1, i, b + c);
STORE(2, i, b - c);
@@ -222,7 +222,6 @@ static void FTransformWHT_C(const int16_t* in, int16_t* out) {
}
#endif // !WEBP_NEON_OMIT_C_CODE
#undef MUL
#undef STORE
//------------------------------------------------------------------------------