libwebp: update to 0.5.0

This commit imports libwebp 0.5.0, including AUTHORS, COPYING, ChangeLog,
NEWS, PATENTS, README and src directories. In src, only includes header
and source files.

The patches required to build it in Qt will follow in separate
commit(s).

Change-Id: I96b4961ba63c75cc7fbab158c36a0f403f254c14
Reviewed-by: aavit <eirik.aavitsland@theqtcompany.com>

1 files changed, 352 insertions, 0 deletions

diff --git a/src/3rdparty/libwebp/src/dsp/filters_sse2.c b/src/3rdparty/libwebp/src/dsp/filters_sse2.c
new file mode 100644
index 0000000..bf93342
--- /dev/null
+++ b/src/3rdparty/libwebp/src/dsp/filters_sse2.c
@@ -0,0 +1,352 @@
+// Copyright 2015 Google Inc. All Rights Reserved.
+//
+// Use of this source code is governed by a BSD-style license
+// that can be found in the COPYING file in the root of the source
+// tree. An additional intellectual property rights grant can be found
+// in the file PATENTS. All contributing project authors may
+// be found in the AUTHORS file in the root of the source tree.
+// -----------------------------------------------------------------------------
+//
+// SSE2 variant of alpha filters
+//
+// Author: Skal (pascal.massimino@gmail.com)
+
+#include "./dsp.h"
+
+#if defined(WEBP_USE_SSE2)
+
+#include <assert.h>
+#include <emmintrin.h>
+#include <stdlib.h>
+#include <string.h>
+
+//------------------------------------------------------------------------------
+// Helpful macro.
+
+# define SANITY_CHECK(in, out)                                                 \
+  assert(in != NULL);                                                          \
+  assert(out != NULL);                                                         \
+  assert(width > 0);                                                           \
+  assert(height > 0);                                                          \
+  assert(stride >= width);                                                     \
+  assert(row >= 0 && num_rows > 0 && row + num_rows <= height);                \
+  (void)height;  // Silence unused warning.
+
+static void PredictLineTop(const uint8_t* src, const uint8_t* pred,
+                           uint8_t* dst, int length, int inverse) {
+  int i;
+  const int max_pos = length & ~31;
+  assert(length >= 0);
+  if (inverse) {
+    for (i = 0; i < max_pos; i += 32) {
+      const __m128i A0 = _mm_loadu_si128((const __m128i*)&src[i +  0]);
+      const __m128i A1 = _mm_loadu_si128((const __m128i*)&src[i + 16]);
+      const __m128i B0 = _mm_loadu_si128((const __m128i*)&pred[i +  0]);
+      const __m128i B1 = _mm_loadu_si128((const __m128i*)&pred[i + 16]);
+      const __m128i C0 = _mm_add_epi8(A0, B0);
+      const __m128i C1 = _mm_add_epi8(A1, B1);
+      _mm_storeu_si128((__m128i*)&dst[i +  0], C0);
+      _mm_storeu_si128((__m128i*)&dst[i + 16], C1);
+    }
+    for (; i < length; ++i) dst[i] = src[i] + pred[i];
+  } else {
+    for (i = 0; i < max_pos; i += 32) {
+      const __m128i A0 = _mm_loadu_si128((const __m128i*)&src[i +  0]);
+      const __m128i A1 = _mm_loadu_si128((const __m128i*)&src[i + 16]);
+      const __m128i B0 = _mm_loadu_si128((const __m128i*)&pred[i +  0]);
+      const __m128i B1 = _mm_loadu_si128((const __m128i*)&pred[i + 16]);
+      const __m128i C0 = _mm_sub_epi8(A0, B0);
+      const __m128i C1 = _mm_sub_epi8(A1, B1);
+      _mm_storeu_si128((__m128i*)&dst[i +  0], C0);
+      _mm_storeu_si128((__m128i*)&dst[i + 16], C1);
+    }
+    for (; i < length; ++i) dst[i] = src[i] - pred[i];
+  }
+}
+
+// Special case for left-based prediction (when preds==dst-1 or preds==src-1).
+static void PredictLineLeft(const uint8_t* src, uint8_t* dst, int length,
+                            int inverse) {
+  int i;
+  if (length <= 0) return;
+  if (inverse) {
+    const int max_pos = length & ~7;
+    __m128i last = _mm_set_epi32(0, 0, 0, dst[-1]);
+    for (i = 0; i < max_pos; i += 8) {
+      const __m128i A0 = _mm_loadl_epi64((const __m128i*)(src + i));
+      const __m128i A1 = _mm_add_epi8(A0, last);
+      const __m128i A2 = _mm_slli_si128(A1, 1);
+      const __m128i A3 = _mm_add_epi8(A1, A2);
+      const __m128i A4 = _mm_slli_si128(A3, 2);
+      const __m128i A5 = _mm_add_epi8(A3, A4);
+      const __m128i A6 = _mm_slli_si128(A5, 4);
+      const __m128i A7 = _mm_add_epi8(A5, A6);
+      _mm_storel_epi64((__m128i*)(dst + i), A7);
+      last = _mm_srli_epi64(A7, 56);
+    }
+    for (; i < length; ++i) dst[i] = src[i] + dst[i - 1];
+  } else {
+    const int max_pos = length & ~31;
+    for (i = 0; i < max_pos; i += 32) {
+      const __m128i A0 = _mm_loadu_si128((const __m128i*)(src + i +  0    ));
+      const __m128i B0 = _mm_loadu_si128((const __m128i*)(src + i +  0 - 1));
+      const __m128i A1 = _mm_loadu_si128((const __m128i*)(src + i + 16    ));
+      const __m128i B1 = _mm_loadu_si128((const __m128i*)(src + i + 16 - 1));
+      const __m128i C0 = _mm_sub_epi8(A0, B0);
+      const __m128i C1 = _mm_sub_epi8(A1, B1);
+      _mm_storeu_si128((__m128i*)(dst + i +  0), C0);
+      _mm_storeu_si128((__m128i*)(dst + i + 16), C1);
+    }
+    for (; i < length; ++i) dst[i] = src[i] - src[i - 1];
+  }
+}
+
+static void PredictLineC(const uint8_t* src, const uint8_t* pred,
+                         uint8_t* dst, int length, int inverse) {
+  int i;
+  if (inverse) {
+    for (i = 0; i < length; ++i) dst[i] = src[i] + pred[i];
+  } else {
+    for (i = 0; i < length; ++i) dst[i] = src[i] - pred[i];
+  }
+}
+
+//------------------------------------------------------------------------------
+// Horizontal filter.
+
+static WEBP_INLINE void DoHorizontalFilter(const uint8_t* in,
+                                           int width, int height, int stride,
+                                           int row, int num_rows,
+                                           int inverse, uint8_t* out) {
+  const uint8_t* preds;
+  const size_t start_offset = row * stride;
+  const int last_row = row + num_rows;
+  SANITY_CHECK(in, out);
+  in += start_offset;
+  out += start_offset;
+  preds = inverse ? out : in;
+
+  if (row == 0) {
+    // Leftmost pixel is the same as input for topmost scanline.
+    out[0] = in[0];
+    PredictLineLeft(in + 1, out + 1, width - 1, inverse);
+    row = 1;
+    preds += stride;
+    in += stride;
+    out += stride;
+  }
+
+  // Filter line-by-line.
+  while (row < last_row) {
+    // Leftmost pixel is predicted from above.
+    PredictLineC(in, preds - stride, out, 1, inverse);
+    PredictLineLeft(in + 1, out + 1, width - 1, inverse);
+    ++row;
+    preds += stride;
+    in += stride;
+    out += stride;
+  }
+}
+
+//------------------------------------------------------------------------------
+// Vertical filter.
+
+static WEBP_INLINE void DoVerticalFilter(const uint8_t* in,
+                                         int width, int height, int stride,
+                                         int row, int num_rows,
+                                         int inverse, uint8_t* out) {
+  const uint8_t* preds;
+  const size_t start_offset = row * stride;
+  const int last_row = row + num_rows;
+  SANITY_CHECK(in, out);
+  in += start_offset;
+  out += start_offset;
+  preds = inverse ? out : in;
+
+  if (row == 0) {
+    // Very first top-left pixel is copied.
+    out[0] = in[0];
+    // Rest of top scan-line is left-predicted.
+    PredictLineLeft(in + 1, out + 1, width - 1, inverse);
+    row = 1;
+    in += stride;
+    out += stride;
+  } else {
+    // We are starting from in-between. Make sure 'preds' points to prev row.
+    preds -= stride;
+  }
+
+  // Filter line-by-line.
+  while (row < last_row) {
+    PredictLineTop(in, preds, out, width, inverse);
+    ++row;
+    preds += stride;
+    in += stride;
+    out += stride;
+  }
+}
+
+//------------------------------------------------------------------------------
+// Gradient filter.
+
+static WEBP_INLINE int GradientPredictorC(uint8_t a, uint8_t b, uint8_t c) {
+  const int g = a + b - c;
+  return ((g & ~0xff) == 0) ? g : (g < 0) ? 0 : 255;  // clip to 8bit
+}
+
+static void GradientPredictDirect(const uint8_t* const row,
+                                  const uint8_t* const top,
+                                  uint8_t* const out, int length) {
+  const int max_pos = length & ~7;
+  int i;
+  const __m128i zero = _mm_setzero_si128();
+  for (i = 0; i < max_pos; i += 8) {
+    const __m128i A0 = _mm_loadl_epi64((const __m128i*)&row[i - 1]);
+    const __m128i B0 = _mm_loadl_epi64((const __m128i*)&top[i]);
+    const __m128i C0 = _mm_loadl_epi64((const __m128i*)&top[i - 1]);
+    const __m128i D = _mm_loadl_epi64((const __m128i*)&row[i]);
+    const __m128i A1 = _mm_unpacklo_epi8(A0, zero);
+    const __m128i B1 = _mm_unpacklo_epi8(B0, zero);
+    const __m128i C1 = _mm_unpacklo_epi8(C0, zero);
+    const __m128i E = _mm_add_epi16(A1, B1);
+    const __m128i F = _mm_sub_epi16(E, C1);
+    const __m128i G = _mm_packus_epi16(F, zero);
+    const __m128i H = _mm_sub_epi8(D, G);
+    _mm_storel_epi64((__m128i*)(out + i), H);
+  }
+  for (; i < length; ++i) {
+    out[i] = row[i] - GradientPredictorC(row[i - 1], top[i], top[i - 1]);
+  }
+}
+
+static void GradientPredictInverse(const uint8_t* const in,
+                                   const uint8_t* const top,
+                                   uint8_t* const row, int length) {
+  if (length > 0) {
+    int i;
+    const int max_pos = length & ~7;
+    const __m128i zero = _mm_setzero_si128();
+    __m128i A = _mm_set_epi32(0, 0, 0, row[-1]);   // left sample
+    for (i = 0; i < max_pos; i += 8) {
+      const __m128i tmp0 = _mm_loadl_epi64((const __m128i*)&top[i]);
+      const __m128i tmp1 = _mm_loadl_epi64((const __m128i*)&top[i - 1]);
+      const __m128i B = _mm_unpacklo_epi8(tmp0, zero);
+      const __m128i C = _mm_unpacklo_epi8(tmp1, zero);
+      const __m128i tmp2 = _mm_loadl_epi64((const __m128i*)&in[i]);
+      const __m128i D = _mm_unpacklo_epi8(tmp2, zero);   // base input
+      const __m128i E = _mm_sub_epi16(B, C);  // unclipped gradient basis B - C
+      __m128i out = zero;                     // accumulator for output
+      __m128i mask_hi = _mm_set_epi32(0, 0, 0, 0xff);
+      int k = 8;
+      while (1) {
+        const __m128i tmp3 = _mm_add_epi16(A, E);        // delta = A + B - C
+        const __m128i tmp4 = _mm_min_epi16(tmp3, mask_hi);
+        const __m128i tmp5 = _mm_max_epi16(tmp4, zero);  // clipped delta
+        const __m128i tmp6 = _mm_add_epi16(tmp5, D);     // add to in[] values
+        A = _mm_and_si128(tmp6, mask_hi);                // 1-complement clip
+        out = _mm_or_si128(out, A);                      // accumulate output
+        if (--k == 0) break;
+        A = _mm_slli_si128(A, 2);                        // rotate left sample
+        mask_hi = _mm_slli_si128(mask_hi, 2);            // rotate mask
+      }
+      A = _mm_srli_si128(A, 14);       // prepare left sample for next iteration
+      _mm_storel_epi64((__m128i*)&row[i], _mm_packus_epi16(out, zero));
+    }
+    for (; i < length; ++i) {
+      row[i] = in[i] + GradientPredictorC(row[i - 1], top[i], top[i - 1]);
+    }
+  }
+}
+
+static WEBP_INLINE void DoGradientFilter(const uint8_t* in,
+                                         int width, int height, int stride,
+                                         int row, int num_rows,
+                                         int inverse, uint8_t* out) {
+  const size_t start_offset = row * stride;
+  const int last_row = row + num_rows;
+  SANITY_CHECK(in, out);
+  in += start_offset;
+  out += start_offset;
+
+  // left prediction for top scan-line
+  if (row == 0) {
+    out[0] = in[0];
+    PredictLineLeft(in + 1, out + 1, width - 1, inverse);
+    row = 1;
+    in += stride;
+    out += stride;
+  }
+
+  // Filter line-by-line.
+  while (row < last_row) {
+    if (inverse) {
+      PredictLineC(in, out - stride, out, 1, inverse);  // predict from above
+      GradientPredictInverse(in + 1, out + 1 - stride, out + 1, width - 1);
+    } else {
+      PredictLineC(in, in - stride, out, 1, inverse);
+      GradientPredictDirect(in + 1, in + 1 - stride, out + 1, width - 1);
+    }
+    ++row;
+    in += stride;
+    out += stride;
+  }
+}
+
+#undef SANITY_CHECK
+
+//------------------------------------------------------------------------------
+
+static void HorizontalFilter(const uint8_t* data, int width, int height,
+                             int stride, uint8_t* filtered_data) {
+  DoHorizontalFilter(data, width, height, stride, 0, height, 0, filtered_data);
+}
+
+static void VerticalFilter(const uint8_t* data, int width, int height,
+                           int stride, uint8_t* filtered_data) {
+  DoVerticalFilter(data, width, height, stride, 0, height, 0, filtered_data);
+}
+
+
+static void GradientFilter(const uint8_t* data, int width, int height,
+                           int stride, uint8_t* filtered_data) {
+  DoGradientFilter(data, width, height, stride, 0, height, 0, filtered_data);
+}
+
+
+//------------------------------------------------------------------------------
+
+static void VerticalUnfilter(int width, int height, int stride, int row,
+                             int num_rows, uint8_t* data) {
+  DoVerticalFilter(data, width, height, stride, row, num_rows, 1, data);
+}
+
+static void HorizontalUnfilter(int width, int height, int stride, int row,
+                               int num_rows, uint8_t* data) {
+  DoHorizontalFilter(data, width, height, stride, row, num_rows, 1, data);
+}
+
+static void GradientUnfilter(int width, int height, int stride, int row,
+                             int num_rows, uint8_t* data) {
+  DoGradientFilter(data, width, height, stride, row, num_rows, 1, data);
+}
+
+//------------------------------------------------------------------------------
+// Entry point
+
+extern void VP8FiltersInitSSE2(void);
+
+WEBP_TSAN_IGNORE_FUNCTION void VP8FiltersInitSSE2(void) {
+  WebPUnfilters[WEBP_FILTER_HORIZONTAL] = HorizontalUnfilter;
+  WebPUnfilters[WEBP_FILTER_VERTICAL] = VerticalUnfilter;
+  WebPUnfilters[WEBP_FILTER_GRADIENT] = GradientUnfilter;
+
+  WebPFilters[WEBP_FILTER_HORIZONTAL] = HorizontalFilter;
+  WebPFilters[WEBP_FILTER_VERTICAL] = VerticalFilter;
+  WebPFilters[WEBP_FILTER_GRADIENT] = GradientFilter;
+}
+
+#else  // !WEBP_USE_SSE2
+
+WEBP_DSP_INIT_STUB(VP8FiltersInitSSE2)
+
+#endif  // WEBP_USE_SSE2