Bundled libwebp updated to version 0.6.0

This commit imports libwebp 0.6.0, including AUTHORS, COPYING, ChangeLog,
NEWS, PATENTS, README and src directories. In src, only includes header
and source files.

Upstream changes since 0.5.1 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: I001aa7a3fabf0130b54f9005c23aa822bc1d0ec1
Reviewed-by: Eirik Aavitsland <eirik.aavitsland@qt.io>

1 files changed, 327 insertions, 0 deletions

diff --git a/src/3rdparty/libwebp/src/dsp/filters_neon.c b/src/3rdparty/libwebp/src/dsp/filters_neon.c
new file mode 100644
index 0000000..4d6e50c
--- /dev/null
+++ b/src/3rdparty/libwebp/src/dsp/filters_neon.c
@@ -0,0 +1,327 @@
+// Copyright 2017 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.
+// -----------------------------------------------------------------------------
+//
+// NEON variant of alpha filters
+//
+// Author: Skal (pascal.massimino@gmail.com)
+
+#include "./dsp.h"
+
+#if defined(WEBP_USE_NEON)
+
+#include <assert.h>
+#include "./neon.h"
+
+//------------------------------------------------------------------------------
+// Helpful macros.
+
+# 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.
+
+// load eight u8 and widen to s16
+#define U8_TO_S16(A) vreinterpretq_s16_u16(vmovl_u8(A))
+#define LOAD_U8_TO_S16(A) U8_TO_S16(vld1_u8(A))
+
+// shift left or right by N byte, inserting zeros
+#define SHIFT_RIGHT_N_Q(A, N) vextq_u8((A), zero, (N))
+#define SHIFT_LEFT_N_Q(A, N) vextq_u8(zero, (A), (16 - (N)) % 16)
+
+// rotate left by N bytes
+#define ROTATE_LEFT_N(A, N)   vext_u8((A), (A), (N))
+// rotate right by N bytes
+#define ROTATE_RIGHT_N(A, N)   vext_u8((A), (A), (8 - (N)) % 8)
+
+static void PredictLine_NEON(const uint8_t* src, const uint8_t* pred,
+                             uint8_t* dst, int length) {
+  int i;
+  assert(length >= 0);
+  for (i = 0; i + 16 <= length; i += 16) {
+    const uint8x16_t A = vld1q_u8(&src[i]);
+    const uint8x16_t B = vld1q_u8(&pred[i]);
+    const uint8x16_t C = vsubq_u8(A, B);
+    vst1q_u8(&dst[i], C);
+  }
+  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_NEON(const uint8_t* src, uint8_t* dst, int length) {
+  PredictLine_NEON(src, src - 1, dst, length);
+}
+
+//------------------------------------------------------------------------------
+// Horizontal filter.
+
+static WEBP_INLINE void DoHorizontalFilter_NEON(const uint8_t* in,
+                                                int width, int height,
+                                                int stride,
+                                                int row, int num_rows,
+                                                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;
+
+  if (row == 0) {
+    // Leftmost pixel is the same as input for topmost scanline.
+    out[0] = in[0];
+    PredictLineLeft_NEON(in + 1, out + 1, width - 1);
+    row = 1;
+    in += stride;
+    out += stride;
+  }
+
+  // Filter line-by-line.
+  while (row < last_row) {
+    // Leftmost pixel is predicted from above.
+    out[0] = in[0] - in[-stride];
+    PredictLineLeft_NEON(in + 1, out + 1, width - 1);
+    ++row;
+    in += stride;
+    out += stride;
+  }
+}
+
+static void HorizontalFilter_NEON(const uint8_t* data, int width, int height,
+                                  int stride, uint8_t* filtered_data) {
+  DoHorizontalFilter_NEON(data, width, height, stride, 0, height,
+                          filtered_data);
+}
+
+//------------------------------------------------------------------------------
+// Vertical filter.
+
+static WEBP_INLINE void DoVerticalFilter_NEON(const uint8_t* in,
+                                              int width, int height, int stride,
+                                              int row, int num_rows,
+                                              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;
+
+  if (row == 0) {
+    // Very first top-left pixel is copied.
+    out[0] = in[0];
+    // Rest of top scan-line is left-predicted.
+    PredictLineLeft_NEON(in + 1, out + 1, width - 1);
+    row = 1;
+    in += stride;
+    out += stride;
+  }
+
+  // Filter line-by-line.
+  while (row < last_row) {
+    PredictLine_NEON(in, in - stride, out, width);
+    ++row;
+    in += stride;
+    out += stride;
+  }
+}
+
+static void VerticalFilter_NEON(const uint8_t* data, int width, int height,
+                               int stride, uint8_t* filtered_data) {
+  DoVerticalFilter_NEON(data, width, height, stride, 0, height,
+                        filtered_data);
+}
+
+//------------------------------------------------------------------------------
+// Gradient filter.
+
+static WEBP_INLINE int GradientPredictor_C(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_NEON(const uint8_t* const row,
+                                       const uint8_t* const top,
+                                       uint8_t* const out, int length) {
+  int i;
+  for (i = 0; i + 8 <= length; i += 8) {
+    const uint8x8_t A = vld1_u8(&row[i - 1]);
+    const uint8x8_t B = vld1_u8(&top[i + 0]);
+    const int16x8_t C = vreinterpretq_s16_u16(vaddl_u8(A, B));
+    const int16x8_t D = LOAD_U8_TO_S16(&top[i - 1]);
+    const uint8x8_t E = vqmovun_s16(vsubq_s16(C, D));
+    const uint8x8_t F = vld1_u8(&row[i + 0]);
+    vst1_u8(&out[i], vsub_u8(F, E));
+  }
+  for (; i < length; ++i) {
+    out[i] = row[i] - GradientPredictor_C(row[i - 1], top[i], top[i - 1]);
+  }
+}
+
+static WEBP_INLINE void DoGradientFilter_NEON(const uint8_t* in,
+                                              int width, int height,
+                                              int stride,
+                                              int row, int num_rows,
+                                              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_NEON(in + 1, out + 1, width - 1);
+    row = 1;
+    in += stride;
+    out += stride;
+  }
+
+  // Filter line-by-line.
+  while (row < last_row) {
+    out[0] = in[0] - in[-stride];
+    GradientPredictDirect_NEON(in + 1, in + 1 - stride, out + 1, width - 1);
+    ++row;
+    in += stride;
+    out += stride;
+  }
+}
+
+static void GradientFilter_NEON(const uint8_t* data, int width, int height,
+                               int stride, uint8_t* filtered_data) {
+  DoGradientFilter_NEON(data, width, height, stride, 0, height,
+                        filtered_data);
+}
+
+#undef SANITY_CHECK
+
+//------------------------------------------------------------------------------
+// Inverse transforms
+
+static void HorizontalUnfilter_NEON(const uint8_t* prev, const uint8_t* in,
+                                    uint8_t* out, int width) {
+  int i;
+  const uint8x16_t zero = vdupq_n_u8(0);
+  uint8x16_t last;
+  out[0] = in[0] + (prev == NULL ? 0 : prev[0]);
+  if (width <= 1) return;
+  last = vsetq_lane_u8(out[0], zero, 0);
+  for (i = 1; i + 16 <= width; i += 16) {
+    const uint8x16_t A0 = vld1q_u8(&in[i]);
+    const uint8x16_t A1 = vaddq_u8(A0, last);
+    const uint8x16_t A2 = SHIFT_LEFT_N_Q(A1, 1);
+    const uint8x16_t A3 = vaddq_u8(A1, A2);
+    const uint8x16_t A4 = SHIFT_LEFT_N_Q(A3, 2);
+    const uint8x16_t A5 = vaddq_u8(A3, A4);
+    const uint8x16_t A6 = SHIFT_LEFT_N_Q(A5, 4);
+    const uint8x16_t A7 = vaddq_u8(A5, A6);
+    const uint8x16_t A8 = SHIFT_LEFT_N_Q(A7, 8);
+    const uint8x16_t A9 = vaddq_u8(A7, A8);
+    vst1q_u8(&out[i], A9);
+    last = SHIFT_RIGHT_N_Q(A9, 15);
+  }
+  for (; i < width; ++i) out[i] = in[i] + out[i - 1];
+}
+
+static void VerticalUnfilter_NEON(const uint8_t* prev, const uint8_t* in,
+                                  uint8_t* out, int width) {
+  if (prev == NULL) {
+    HorizontalUnfilter_NEON(NULL, in, out, width);
+  } else {
+    int i;
+    assert(width >= 0);
+    for (i = 0; i + 16 <= width; i += 16) {
+      const uint8x16_t A = vld1q_u8(&in[i]);
+      const uint8x16_t B = vld1q_u8(&prev[i]);
+      const uint8x16_t C = vaddq_u8(A, B);
+      vst1q_u8(&out[i], C);
+    }
+    for (; i < width; ++i) out[i] = in[i] + prev[i];
+  }
+}
+
+// GradientUnfilter_NEON is correct but slower than the C-version,
+// at least on ARM64. For armv7, it's a wash.
+// So best is to disable it for now, but keep the idea around...
+// #define USE_GRADIENT_UNFILTER
+
+#if defined(USE_GRADIENT_UNFILTER)
+#define GRAD_PROCESS_LANE(L)  do {                                             \
+  const uint8x8_t tmp1 = ROTATE_RIGHT_N(pred, 1);  /* rotate predictor in */   \
+  const int16x8_t tmp2 = vaddq_s16(BC, U8_TO_S16(tmp1));                       \
+  const uint8x8_t delta = vqmovun_s16(tmp2);                                   \
+  pred = vadd_u8(D, delta);                                                    \
+  out = vext_u8(out, ROTATE_LEFT_N(pred, (L)), 1);                             \
+} while (0)
+
+static void GradientPredictInverse_NEON(const uint8_t* const in,
+                                        const uint8_t* const top,
+                                        uint8_t* const row, int length) {
+  if (length > 0) {
+    int i;
+    uint8x8_t pred = vdup_n_u8(row[-1]);   // left sample
+    uint8x8_t out = vdup_n_u8(0);
+    for (i = 0; i + 8 <= length; i += 8) {
+      const int16x8_t B = LOAD_U8_TO_S16(&top[i + 0]);
+      const int16x8_t C = LOAD_U8_TO_S16(&top[i - 1]);
+      const int16x8_t BC = vsubq_s16(B, C);  // unclipped gradient basis B - C
+      const uint8x8_t D = vld1_u8(&in[i]);   // base input
+      GRAD_PROCESS_LANE(0);
+      GRAD_PROCESS_LANE(1);
+      GRAD_PROCESS_LANE(2);
+      GRAD_PROCESS_LANE(3);
+      GRAD_PROCESS_LANE(4);
+      GRAD_PROCESS_LANE(5);
+      GRAD_PROCESS_LANE(6);
+      GRAD_PROCESS_LANE(7);
+      vst1_u8(&row[i], out);
+    }
+    for (; i < length; ++i) {
+      row[i] = in[i] + GradientPredictor_C(row[i - 1], top[i], top[i - 1]);
+    }
+  }
+}
+#undef GRAD_PROCESS_LANE
+
+static void GradientUnfilter_NEON(const uint8_t* prev, const uint8_t* in,
+                                 uint8_t* out, int width) {
+  if (prev == NULL) {
+    HorizontalUnfilter_NEON(NULL, in, out, width);
+  } else {
+    out[0] = in[0] + prev[0];  // predict from above
+    GradientPredictInverse_NEON(in + 1, prev + 1, out + 1, width - 1);
+  }
+}
+
+#endif   // USE_GRADIENT_UNFILTER
+
+//------------------------------------------------------------------------------
+// Entry point
+
+extern void VP8FiltersInitNEON(void);
+
+WEBP_TSAN_IGNORE_FUNCTION void VP8FiltersInitNEON(void) {
+  WebPUnfilters[WEBP_FILTER_HORIZONTAL] = HorizontalUnfilter_NEON;
+  WebPUnfilters[WEBP_FILTER_VERTICAL] = VerticalUnfilter_NEON;
+#if defined(USE_GRADIENT_UNFILTER)
+  WebPUnfilters[WEBP_FILTER_GRADIENT] = GradientUnfilter_NEON;
+#endif
+
+  WebPFilters[WEBP_FILTER_HORIZONTAL] = HorizontalFilter_NEON;
+  WebPFilters[WEBP_FILTER_VERTICAL] = VerticalFilter_NEON;
+  WebPFilters[WEBP_FILTER_GRADIENT] = GradientFilter_NEON;
+}
+
+#else  // !WEBP_USE_NEON
+
+WEBP_DSP_INIT_STUB(VP8FiltersInitNEON)
+
+#endif  // WEBP_USE_NEON