Adding libwebp: Adding clean copy of libwebp 0.4.0

This commit imports libwebp 0.4.0, 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).

Task-number: QTBUG-14205
Change-Id: I747918fe2a07716f66cffb795129f7aa5e067759
Reviewed-by: Lars Knoll <lars.knoll@digia.com>

1 files changed, 210 insertions, 0 deletions

diff --git a/src/3rdparty/libwebp/src/dec/buffer.c b/src/3rdparty/libwebp/src/dec/buffer.c
new file mode 100644
index 0000000..1e852ef
--- /dev/null
+++ b/src/3rdparty/libwebp/src/dec/buffer.c
@@ -0,0 +1,210 @@
+// Copyright 2011 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.
+// -----------------------------------------------------------------------------
+//
+// Everything about WebPDecBuffer
+//
+// Author: Skal (pascal.massimino@gmail.com)
+
+#include <stdlib.h>
+
+#include "./vp8i.h"
+#include "./webpi.h"
+#include "../utils/utils.h"
+
+//------------------------------------------------------------------------------
+// WebPDecBuffer
+
+// Number of bytes per pixel for the different color-spaces.
+static const int kModeBpp[MODE_LAST] = {
+  3, 4, 3, 4, 4, 2, 2,
+  4, 4, 4, 2,    // pre-multiplied modes
+  1, 1 };
+
+// Check that webp_csp_mode is within the bounds of WEBP_CSP_MODE.
+// Convert to an integer to handle both the unsigned/signed enum cases
+// without the need for casting to remove type limit warnings.
+static int IsValidColorspace(int webp_csp_mode) {
+  return (webp_csp_mode >= MODE_RGB && webp_csp_mode < MODE_LAST);
+}
+
+static VP8StatusCode CheckDecBuffer(const WebPDecBuffer* const buffer) {
+  int ok = 1;
+  const WEBP_CSP_MODE mode = buffer->colorspace;
+  const int width = buffer->width;
+  const int height = buffer->height;
+  if (!IsValidColorspace(mode)) {
+    ok = 0;
+  } else if (!WebPIsRGBMode(mode)) {   // YUV checks
+    const WebPYUVABuffer* const buf = &buffer->u.YUVA;
+    const uint64_t y_size = (uint64_t)buf->y_stride * height;
+    const uint64_t u_size = (uint64_t)buf->u_stride * ((height + 1) / 2);
+    const uint64_t v_size = (uint64_t)buf->v_stride * ((height + 1) / 2);
+    const uint64_t a_size = (uint64_t)buf->a_stride * height;
+    ok &= (y_size <= buf->y_size);
+    ok &= (u_size <= buf->u_size);
+    ok &= (v_size <= buf->v_size);
+    ok &= (buf->y_stride >= width);
+    ok &= (buf->u_stride >= (width + 1) / 2);
+    ok &= (buf->v_stride >= (width + 1) / 2);
+    ok &= (buf->y != NULL);
+    ok &= (buf->u != NULL);
+    ok &= (buf->v != NULL);
+    if (mode == MODE_YUVA) {
+      ok &= (buf->a_stride >= width);
+      ok &= (a_size <= buf->a_size);
+      ok &= (buf->a != NULL);
+    }
+  } else {    // RGB checks
+    const WebPRGBABuffer* const buf = &buffer->u.RGBA;
+    const uint64_t size = (uint64_t)buf->stride * height;
+    ok &= (size <= buf->size);
+    ok &= (buf->stride >= width * kModeBpp[mode]);
+    ok &= (buf->rgba != NULL);
+  }
+  return ok ? VP8_STATUS_OK : VP8_STATUS_INVALID_PARAM;
+}
+
+static VP8StatusCode AllocateBuffer(WebPDecBuffer* const buffer) {
+  const int w = buffer->width;
+  const int h = buffer->height;
+  const WEBP_CSP_MODE mode = buffer->colorspace;
+
+  if (w <= 0 || h <= 0 || !IsValidColorspace(mode)) {
+    return VP8_STATUS_INVALID_PARAM;
+  }
+
+  if (!buffer->is_external_memory && buffer->private_memory == NULL) {
+    uint8_t* output;
+    int uv_stride = 0, a_stride = 0;
+    uint64_t uv_size = 0, a_size = 0, total_size;
+    // We need memory and it hasn't been allocated yet.
+    // => initialize output buffer, now that dimensions are known.
+    const int stride = w * kModeBpp[mode];
+    const uint64_t size = (uint64_t)stride * h;
+
+    if (!WebPIsRGBMode(mode)) {
+      uv_stride = (w + 1) / 2;
+      uv_size = (uint64_t)uv_stride * ((h + 1) / 2);
+      if (mode == MODE_YUVA) {
+        a_stride = w;
+        a_size = (uint64_t)a_stride * h;
+      }
+    }
+    total_size = size + 2 * uv_size + a_size;
+
+    // Security/sanity checks
+    output = (uint8_t*)WebPSafeMalloc(total_size, sizeof(*output));
+    if (output == NULL) {
+      return VP8_STATUS_OUT_OF_MEMORY;
+    }
+    buffer->private_memory = output;
+
+    if (!WebPIsRGBMode(mode)) {   // YUVA initialization
+      WebPYUVABuffer* const buf = &buffer->u.YUVA;
+      buf->y = output;
+      buf->y_stride = stride;
+      buf->y_size = (size_t)size;
+      buf->u = output + size;
+      buf->u_stride = uv_stride;
+      buf->u_size = (size_t)uv_size;
+      buf->v = output + size + uv_size;
+      buf->v_stride = uv_stride;
+      buf->v_size = (size_t)uv_size;
+      if (mode == MODE_YUVA) {
+        buf->a = output + size + 2 * uv_size;
+      }
+      buf->a_size = (size_t)a_size;
+      buf->a_stride = a_stride;
+    } else {  // RGBA initialization
+      WebPRGBABuffer* const buf = &buffer->u.RGBA;
+      buf->rgba = output;
+      buf->stride = stride;
+      buf->size = (size_t)size;
+    }
+  }
+  return CheckDecBuffer(buffer);
+}
+
+VP8StatusCode WebPAllocateDecBuffer(int w, int h,
+                                    const WebPDecoderOptions* const options,
+                                    WebPDecBuffer* const out) {
+  if (out == NULL || w <= 0 || h <= 0) {
+    return VP8_STATUS_INVALID_PARAM;
+  }
+  if (options != NULL) {    // First, apply options if there is any.
+    if (options->use_cropping) {
+      const int cw = options->crop_width;
+      const int ch = options->crop_height;
+      const int x = options->crop_left & ~1;
+      const int y = options->crop_top & ~1;
+      if (x < 0 || y < 0 || cw <= 0 || ch <= 0 || x + cw > w || y + ch > h) {
+        return VP8_STATUS_INVALID_PARAM;   // out of frame boundary.
+      }
+      w = cw;
+      h = ch;
+    }
+    if (options->use_scaling) {
+      if (options->scaled_width <= 0 || options->scaled_height <= 0) {
+        return VP8_STATUS_INVALID_PARAM;
+      }
+      w = options->scaled_width;
+      h = options->scaled_height;
+    }
+  }
+  out->width = w;
+  out->height = h;
+
+  // Then, allocate buffer for real
+  return AllocateBuffer(out);
+}
+
+//------------------------------------------------------------------------------
+// constructors / destructors
+
+int WebPInitDecBufferInternal(WebPDecBuffer* buffer, int version) {
+  if (WEBP_ABI_IS_INCOMPATIBLE(version, WEBP_DECODER_ABI_VERSION)) {
+    return 0;  // version mismatch
+  }
+  if (buffer == NULL) return 0;
+  memset(buffer, 0, sizeof(*buffer));
+  return 1;
+}
+
+void WebPFreeDecBuffer(WebPDecBuffer* buffer) {
+  if (buffer != NULL) {
+    if (!buffer->is_external_memory)
+      free(buffer->private_memory);
+    buffer->private_memory = NULL;
+  }
+}
+
+void WebPCopyDecBuffer(const WebPDecBuffer* const src,
+                       WebPDecBuffer* const dst) {
+  if (src != NULL && dst != NULL) {
+    *dst = *src;
+    if (src->private_memory != NULL) {
+      dst->is_external_memory = 1;   // dst buffer doesn't own the memory.
+      dst->private_memory = NULL;
+    }
+  }
+}
+
+// Copy and transfer ownership from src to dst (beware of parameter order!)
+void WebPGrabDecBuffer(WebPDecBuffer* const src, WebPDecBuffer* const dst) {
+  if (src != NULL && dst != NULL) {
+    *dst = *src;
+    if (src->private_memory != NULL) {
+      src->is_external_memory = 1;   // src relinquishes ownership
+      src->private_memory = NULL;
+    }
+  }
+}
+
+//------------------------------------------------------------------------------
+