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~30% faster smart-yuv (-pre 4) with early-out criterion

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we look at average global improvement and stop when things are
moving slow, or when we had a quite good first iteration already
(means: the picture is "not difficult")

Change-Id: I8ab7d100353039b5b32bb5fac3fe03c8440c78d5
This commit is contained in:
Pascal Massimino 2015-03-06 14:57:07 -08:00
parent 44bd95612e
commit b1bdbbabfb
1 changed files with 35 additions and 8 deletions
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43
src/enc/picture_csp.c
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@ -277,14 +277,18 @@ static WEBP_INLINE void UpdateW(const fixed_y_t* src, fixed_y_t* dst, int len) {
}
}
static WEBP_INLINE void UpdateChroma(const fixed_y_t* src1,
const fixed_y_t* src2,
fixed_t* dst, fixed_y_t* tmp, int len) {
static int UpdateChroma(const fixed_y_t* src1,
const fixed_y_t* src2,
fixed_t* dst, fixed_y_t* tmp, int len) {
int diff = 0;
while (len--> 0) {
const int r = ScaleDown(src1[0], src1[3], src2[0], src2[3]);
const int g = ScaleDown(src1[1], src1[4], src2[1], src2[4]);
const int b = ScaleDown(src1[2], src1[5], src2[2], src2[5]);
const int W = RGBToGray(r, g, b);
const int r_avg = (src1[0] + src1[3] + src2[0] + src2[3] + 2) >> 2;
const int g_avg = (src1[1] + src1[4] + src2[1] + src2[4] + 2) >> 2;
const int b_avg = (src1[2] + src1[5] + src2[2] + src2[5] + 2) >> 2;
dst[0] = (fixed_t)FixedYToW(r - W);
dst[1] = (fixed_t)FixedYToW(g - W);
dst[2] = (fixed_t)FixedYToW(b - W);
@ -292,10 +296,12 @@ static WEBP_INLINE void UpdateChroma(const fixed_y_t* src1,
src1 += 6;
src2 += 6;
if (tmp != NULL) {
tmp[0] = tmp[1] = clip_y((int)(W + .5));
tmp[0] = tmp[1] = clip_y(W);
tmp += 2;
}
diff += abs(RGBToGray(r_avg, g_avg, b_avg) - W);
}
return diff;
}
//------------------------------------------------------------------------------
@ -454,6 +460,10 @@ static int PreprocessARGB(const uint8_t* const r_ptr,
fixed_t* const target_uv = SAFE_ALLOC(uv_w * 3, uv_h, fixed_t);
fixed_t* const best_rgb_uv = SAFE_ALLOC(uv_w * 3, 1, fixed_t);
int ok;
int diff_sum = 0;
const int first_diff_threshold = (int)(2.5 * w * h);
const int min_improvement = 5; // stop if improvement is below this %
const int min_first_improvement = 80;
if (best_y == NULL || best_uv == NULL ||
target_y == NULL || target_uv == NULL ||
@ -486,7 +496,7 @@ static int PreprocessARGB(const uint8_t* const r_ptr,
}
UpdateW(src1, target_y + (j + 0) * w, w);
UpdateW(src2, target_y + (j + 1) * w, w);
UpdateChroma(src1, src2, target_uv + uv_off, dst_y, uv_w);
diff_sum += UpdateChroma(src1, src2, target_uv + uv_off, dst_y, uv_w);
memcpy(best_uv + uv_off, target_uv + uv_off, 3 * uv_w * sizeof(*best_uv));
memcpy(dst_y + w, dst_y, w * sizeof(*dst_y));
}
@ -496,10 +506,11 @@ static int PreprocessARGB(const uint8_t* const r_ptr,
int k;
const fixed_t* cur_uv = best_uv;
const fixed_t* prev_uv = best_uv;
const int old_diff_sum = diff_sum;
diff_sum = 0;
for (j = 0; j < h; j += 2) {
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,
@ -510,7 +521,7 @@ static int PreprocessARGB(const uint8_t* const r_ptr,
UpdateW(src1, best_rgb_y + 0 * w, w);
UpdateW(src2, best_rgb_y + 1 * w, w);
UpdateChroma(src1, src2, best_rgb_uv, NULL, uv_w);
diff_sum += UpdateChroma(src1, src2, best_rgb_uv, NULL, uv_w);
// update two rows of Y and one row of RGB
for (i = 0; i < 2 * w; ++i) {
@ -532,7 +543,23 @@ static int PreprocessARGB(const uint8_t* const r_ptr,
}
}
}
// TODO(skal): add early-termination criterion
// test exit condition
if (diff_sum > 0) {
const int improvement = 100 * abs(diff_sum - old_diff_sum) / diff_sum;
// Check if first iteration gave good result already, without a large
// jump of improvement (otherwise it means we need to try few extra
// iterations, just to be sure).
if (iter == 0 && diff_sum < first_diff_threshold &&
improvement < min_first_improvement) {
break;
}
// then, check if improvement is stalling.
if (improvement < min_improvement) {
break;
}
} else {
break;
}
}
// final reconstruction