Bundled libwebp updated to version 0.5.1

This commit imports libwebp 0.5.1, including AUTHORS, COPYING, ChangeLog,
NEWS, PATENTS, README and src directories. In src, only includes header
and source files.

Upstream changes since 0.5.0 have been merged in.
Also updated version in qt_attribution.json.

Conflicts:
	src/3rdparty/libwebp.pri
	src/3rdparty/libwebp/qt_attribution.json
	src/3rdparty/libwebp/src/webp/config.h

Change-Id: I7d0c15400154c3b4ee8ff37665303307c4b84f9f
Reviewed-by: Oswald Buddenhagen <oswald.buddenhagen@qt.io>
Reviewed-by: Eirik Aavitsland <eirik.aavitsland@qt.io>

1 files changed, 66 insertions, 3 deletions

diff --git a/src/3rdparty/libwebp/src/dsp/enc.c b/src/3rdparty/libwebp/src/dsp/enc.c
index 8899d50..f639f55 100644
--- a/src/3rdparty/libwebp/src/dsp/enc.c
+++ b/src/3rdparty/libwebp/src/dsp/enc.c
@@ -69,7 +69,7 @@ static void CollectHistogram(const uint8_t* ref, const uint8_t* pred,
 
     // Convert coefficients to bin.
     for (k = 0; k < 16; ++k) {
-      const int v = abs(out[k]) >> 3;  // TODO(skal): add rounding?
+      const int v = abs(out[k]) >> 3;
       const int clipped_value = clip_max(v, MAX_COEFF_THRESH);
       ++distribution[clipped_value];
     }
@@ -559,6 +559,7 @@ static int SSE4x4(const uint8_t* a, const uint8_t* b) {
 
 // Hadamard transform
 // Returns the weighted sum of the absolute value of transformed coefficients.
+// w[] contains a row-major 4 by 4 symmetric matrix.
 static int TTransform(const uint8_t* in, const uint16_t* w) {
   int sum = 0;
   int tmp[16];
@@ -636,7 +637,7 @@ static int QuantizeBlock(int16_t in[16], int16_t out[16],
       int level = QUANTDIV(coeff, iQ, B);
       if (level > MAX_LEVEL) level = MAX_LEVEL;
       if (sign) level = -level;
-      in[j] = level * Q;
+      in[j] = level * (int)Q;
       out[n] = level;
       if (level) last = n;
     } else {
@@ -670,7 +671,7 @@ static int QuantizeBlockWHT(int16_t in[16], int16_t out[16],
       int level = QUANTDIV(coeff, iQ, B);
       if (level > MAX_LEVEL) level = MAX_LEVEL;
       if (sign) level = -level;
-      in[j] = level * Q;
+      in[j] = level * (int)Q;
       out[n] = level;
       if (level) last = n;
     } else {
@@ -702,6 +703,68 @@ static void Copy16x8(const uint8_t* src, uint8_t* dst) {
 }
 
 //------------------------------------------------------------------------------
+
+static void SSIMAccumulateClipped(const uint8_t* src1, int stride1,
+                                  const uint8_t* src2, int stride2,
+                                  int xo, int yo, int W, int H,
+                                  VP8DistoStats* const stats) {
+  const int ymin = (yo - VP8_SSIM_KERNEL < 0) ? 0 : yo - VP8_SSIM_KERNEL;
+  const int ymax = (yo + VP8_SSIM_KERNEL > H - 1) ? H - 1
+                                                  : yo + VP8_SSIM_KERNEL;
+  const int xmin = (xo - VP8_SSIM_KERNEL < 0) ? 0 : xo - VP8_SSIM_KERNEL;
+  const int xmax = (xo + VP8_SSIM_KERNEL > W - 1) ? W - 1
+                                                  : xo + VP8_SSIM_KERNEL;
+  int x, y;
+  src1 += ymin * stride1;
+  src2 += ymin * stride2;
+  for (y = ymin; y <= ymax; ++y, src1 += stride1, src2 += stride2) {
+    for (x = xmin; x <= xmax; ++x) {
+      const int s1 = src1[x];
+      const int s2 = src2[x];
+      stats->w   += 1;
+      stats->xm  += s1;
+      stats->ym  += s2;
+      stats->xxm += s1 * s1;
+      stats->xym += s1 * s2;
+      stats->yym += s2 * s2;
+    }
+  }
+}
+
+static void SSIMAccumulate(const uint8_t* src1, int stride1,
+                           const uint8_t* src2, int stride2,
+                           VP8DistoStats* const stats) {
+  int x, y;
+  for (y = 0; y <= 2 * VP8_SSIM_KERNEL; ++y, src1 += stride1, src2 += stride2) {
+    for (x = 0; x <= 2 * VP8_SSIM_KERNEL; ++x) {
+      const int s1 = src1[x];
+      const int s2 = src2[x];
+      stats->w   += 1;
+      stats->xm  += s1;
+      stats->ym  += s2;
+      stats->xxm += s1 * s1;
+      stats->xym += s1 * s2;
+      stats->yym += s2 * s2;
+    }
+  }
+}
+
+VP8SSIMAccumulateFunc VP8SSIMAccumulate;
+VP8SSIMAccumulateClippedFunc VP8SSIMAccumulateClipped;
+
+static volatile VP8CPUInfo ssim_last_cpuinfo_used =
+    (VP8CPUInfo)&ssim_last_cpuinfo_used;
+
+WEBP_TSAN_IGNORE_FUNCTION void VP8SSIMDspInit(void) {
+  if (ssim_last_cpuinfo_used == VP8GetCPUInfo) return;
+
+  VP8SSIMAccumulate = SSIMAccumulate;
+  VP8SSIMAccumulateClipped = SSIMAccumulateClipped;
+
+  ssim_last_cpuinfo_used = VP8GetCPUInfo;
+}
+
+//------------------------------------------------------------------------------
 // Initialization
 
 // Speed-critical function pointers. We have to initialize them to the default