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PreprocessARGB: use relative pointer offsets

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avoids int rollover when working with large input

BUG=webp:312

Change-Id: I2881bec2884b550c966108beeff1bf0d8ef9f76b
This commit is contained in:
James Zern 2016-11-07 23:26:54 +00:00
parent e4cd4daf74
commit 1147ab4ee7
1 changed files with 48 additions and 37 deletions
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85
src/enc/picture_csp.c
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@ -438,9 +438,9 @@ static int ConvertWRGBToYUV(const fixed_y_t* best_y, const fixed_t* best_uv,
#define SAFE_ALLOC(W, H, T) ((T*)WebPSafeMalloc((W) * (H), sizeof(T)))
static int PreprocessARGB(const uint8_t* const r_ptr,
const uint8_t* const g_ptr,
const uint8_t* const b_ptr,
static int PreprocessARGB(const uint8_t* r_ptr,
const uint8_t* g_ptr,
const uint8_t* b_ptr,
int step, int rgb_stride,
WebPPicture* const picture) {
// we expand the right/bottom border if needed
@ -454,17 +454,21 @@ static int PreprocessARGB(const uint8_t* const r_ptr,
// TODO(skal): allocate one big memory chunk. But for now, it's easier
// for valgrind debugging to have several chunks.
fixed_y_t* const tmp_buffer = SAFE_ALLOC(w * 3, 2, fixed_y_t); // scratch
fixed_y_t* const best_y = SAFE_ALLOC(w, h, fixed_y_t);
fixed_y_t* const target_y = SAFE_ALLOC(w, h, fixed_y_t);
fixed_y_t* const best_y_base = SAFE_ALLOC(w, h, fixed_y_t);
fixed_y_t* const target_y_base = SAFE_ALLOC(w, h, fixed_y_t);
fixed_y_t* const best_rgb_y = SAFE_ALLOC(w, 2, fixed_y_t);
fixed_t* const best_uv = SAFE_ALLOC(uv_w * 3, uv_h, fixed_t);
fixed_t* const target_uv = SAFE_ALLOC(uv_w * 3, uv_h, fixed_t);
fixed_t* const best_uv_base = SAFE_ALLOC(uv_w * 3, uv_h, fixed_t);
fixed_t* const target_uv_base = SAFE_ALLOC(uv_w * 3, uv_h, fixed_t);
fixed_t* const best_rgb_uv = SAFE_ALLOC(uv_w * 3, 1, fixed_t);
fixed_y_t* best_y = best_y_base;
fixed_y_t* target_y = target_y_base;
fixed_t* best_uv = best_uv_base;
fixed_t* target_uv = target_uv_base;
const uint64_t diff_y_threshold = (uint64_t)(3.0 * w * h);
int ok;
if (best_y == NULL || best_uv == NULL ||
target_y == NULL || target_uv == NULL ||
if (best_y_base == NULL || best_uv_base == NULL ||
target_y_base == NULL || target_uv_base == NULL ||
best_rgb_y == NULL || best_rgb_uv == NULL ||
tmp_buffer == NULL) {
ok = WebPEncodingSetError(picture, VP8_ENC_ERROR_OUT_OF_MEMORY);
@ -478,42 +482,46 @@ static int PreprocessARGB(const uint8_t* const r_ptr,
const int is_last_row = (j == picture->height - 1);
fixed_y_t* const src1 = tmp_buffer;
fixed_y_t* const src2 = tmp_buffer + 3 * w;
const int off1 = j * rgb_stride;
const int off2 = off1 + rgb_stride;
const int uv_off = (j >> 1) * 3 * uv_w;
fixed_y_t* const dst_y = best_y + j * w;
// prepare two rows of input
ImportOneRow(r_ptr + off1, g_ptr + off1, b_ptr + off1,
step, picture->width, src1);
ImportOneRow(r_ptr, g_ptr, b_ptr, step, picture->width, src1);
if (!is_last_row) {
ImportOneRow(r_ptr + off2, g_ptr + off2, b_ptr + off2,
ImportOneRow(r_ptr + rgb_stride, g_ptr + rgb_stride, b_ptr + rgb_stride,
step, picture->width, src2);
} else {
memcpy(src2, src1, 3 * w * sizeof(*src2));
}
StoreGray(src1, dst_y, 2 * w); // convert two lines at a time
StoreGray(src1, best_y, 2 * w); // convert two lines at a time
UpdateW(src1, target_y + (j + 0) * w, w);
UpdateW(src2, target_y + (j + 1) * w, w);
UpdateChroma(src1, src2, target_uv + uv_off, uv_w);
memcpy(best_uv + uv_off, target_uv + uv_off, 3 * uv_w * sizeof(*best_uv));
UpdateW(src1, target_y, w);
UpdateW(src2, target_y + w, w);
UpdateChroma(src1, src2, target_uv, uv_w);
memcpy(best_uv, target_uv, 3 * uv_w * sizeof(*best_uv));
best_y += 2 * w;
best_uv += 3 * uv_w;
target_y += 2 * w;
target_uv += 3 * uv_w;
r_ptr += 2 * rgb_stride;
g_ptr += 2 * rgb_stride;
b_ptr += 2 * rgb_stride;
}
// Iterate and resolve clipping conflicts.
for (iter = 0; iter < kNumIterations; ++iter) {
const fixed_t* cur_uv = best_uv;
const fixed_t* prev_uv = best_uv;
const fixed_t* cur_uv = best_uv_base;
const fixed_t* prev_uv = best_uv_base;
uint64_t diff_y_sum = 0;
best_y = best_y_base;
best_uv = best_uv_base;
target_y = target_y_base;
target_uv = target_uv_base;
for (j = 0; j < h; j += 2) {
const int uv_off = (j >> 1) * 3 * uv_w;
fixed_y_t* const src1 = tmp_buffer;
fixed_y_t* const src2 = tmp_buffer + 3 * w;
{
const fixed_t* const next_uv = cur_uv + ((j < h - 2) ? 3 * uv_w : 0);
InterpolateTwoRows(best_y + j * w, prev_uv, cur_uv, next_uv,
w, src1, src2);
InterpolateTwoRows(best_y, prev_uv, cur_uv, next_uv, w, src1, src2);
prev_uv = cur_uv;
cur_uv = next_uv;
}
@ -524,16 +532,19 @@ static int PreprocessARGB(const uint8_t* const r_ptr,
// update two rows of Y and one row of RGB
for (i = 0; i < 2 * w; ++i) {
const int off = i + j * w;
const int diff_y = target_y[off] - best_rgb_y[i];
const int new_y = (int)best_y[off] + diff_y;
best_y[off] = clip_y(new_y);
const int diff_y = target_y[i] - best_rgb_y[i];
const int new_y = (int)best_y[i] + diff_y;
best_y[i] = clip_y(new_y);
diff_y_sum += (uint64_t)abs(diff_y);
}
for (i = 0; i < 3 * uv_w; ++i) {
const int diff_uv = (int)target_uv[uv_off + i] - best_rgb_uv[i];
best_uv[uv_off + i] += diff_uv;
const int diff_uv = (int)target_uv[i] - best_rgb_uv[i];
best_uv[i] += diff_uv;
}
best_y += 2 * w;
best_uv += 3 * uv_w;
target_y += 2 * w;
target_uv += 3 * uv_w;
}
// test exit condition
if (iter > 0) {
@ -543,13 +554,13 @@ static int PreprocessARGB(const uint8_t* const r_ptr,
prev_diff_y_sum = diff_y_sum;
}
// final reconstruction
ok = ConvertWRGBToYUV(best_y, best_uv, picture);
ok = ConvertWRGBToYUV(best_y_base, best_uv_base, picture);
End:
WebPSafeFree(best_y);
WebPSafeFree(best_uv);
WebPSafeFree(target_y);
WebPSafeFree(target_uv);
WebPSafeFree(best_y_base);
WebPSafeFree(best_uv_base);
WebPSafeFree(target_y_base);
WebPSafeFree(target_uv_base);
WebPSafeFree(best_rgb_y);
WebPSafeFree(best_rgb_uv);
WebPSafeFree(tmp_buffer);