1 files changed, 140 insertions, 0 deletions
diff --git a/media/base/video_frame_impl.cc b/media/base/video_frame_impl.cc
new file mode 100644
index 0000000..8d9ae59
--- /dev/null
+++ b/media/base/video_frame_impl.cc
@@ -0,0 +1,140 @@
+// Copyright (c) 2009 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "media/base/video_frame_impl.h"
+
+namespace media {
+
+// static
+void VideoFrameImpl::CreateFrame(VideoSurface::Format format,
+                                 size_t width,
+                                 size_t height,
+                                 base::TimeDelta timestamp,
+                                 base::TimeDelta duration,
+                                 scoped_refptr<VideoFrame>* frame_out) {
+  DCHECK(width > 0 && height > 0);
+  DCHECK(width * height < 100000000);
+  DCHECK(frame_out);
+  bool alloc_worked = false;
+  scoped_refptr<VideoFrameImpl> frame =
+      new VideoFrameImpl(format, width, height);
+  if (frame) {
+    frame->SetTimestamp(timestamp);
+    frame->SetDuration(duration);
+    switch (format) {
+      case VideoSurface::RGB555:
+      case VideoSurface::RGB565:
+        alloc_worked = frame->AllocateRGB(2u);
+        break;
+      case VideoSurface::RGB24:
+        alloc_worked = frame->AllocateRGB(3u);
+        break;
+      case VideoSurface::RGB32:
+      case VideoSurface::RGBA:
+        alloc_worked = frame->AllocateRGB(4u);
+        break;
+      case VideoSurface::YV12:
+      case VideoSurface::YV16:
+        alloc_worked = frame->AllocateYUV();
+        break;
+      default:
+        NOTREACHED();
+        alloc_worked = false;
+        break;
+    }
+  }
+  *frame_out = alloc_worked ? frame : NULL;
+}
+
+static inline size_t RoundUp(size_t value, size_t alignment) {
+  // Check that |alignment| is a power of 2.
+  DCHECK((alignment + (alignment - 1)) == (alignment | (alignment - 1)));
+  return ((value + (alignment - 1)) & ~(alignment-1));
+}
+
+bool VideoFrameImpl::AllocateRGB(size_t bytes_per_pixel) {
+  // Round up to align at a 64-bit (8 byte) boundary for each row.  This
+  // is sufficient for MMX reads (movq).
+  size_t bytes_per_row = RoundUp(surface_.width * bytes_per_pixel, 8);
+  surface_.planes = VideoSurface::kNumRGBPlanes;
+  surface_.strides[VideoSurface::kRGBPlane] = bytes_per_row;
+  surface_.data[VideoSurface::kRGBPlane] = new uint8[bytes_per_row *
+                                                     surface_.height];
+  DCHECK(surface_.data[VideoSurface::kRGBPlane]);
+  DCHECK(!(reinterpret_cast<int>(surface_.data[VideoSurface::kRGBPlane]) & 7));
+  COMPILE_ASSERT(0 == VideoSurface::kRGBPlane, RGB_data_must_be_index_0);
+  return (NULL != surface_.data[VideoSurface::kRGBPlane]);
+}
+
+bool VideoFrameImpl::AllocateYUV() {
+  DCHECK(surface_.format == VideoSurface::YV12 ||
+         surface_.format == VideoSurface::YV16);
+  // Align Y rows at 32-bit (4 byte) boundaries.  The stride for both YV12 and
+  // YV16 is 1/2 of the stride of Y.  For YV12, every row of bytes for U and V
+  // applies to two rows of Y (one byte of UV for 4 bytes of Y), so in the
+  // case of YV12 the strides are identical for the same width surface, but the
+  // number of bytes allocated for YV12 is 1/2 the amount for U & V as YV16.
+  // We also round the height of the surface allocated to be an even number
+  // to avoid any potential of faulting by code that attempts to access the Y
+  // values of the final row, but assumes that the last row of U & V applies to
+  // a full two rows of Y.
+  size_t alloc_height = RoundUp(surface_.height, 2);
+  size_t y_bytes_per_row = RoundUp(surface_.width, 4);
+  size_t uv_stride = RoundUp(y_bytes_per_row / 2, 4);
+  size_t y_bytes = alloc_height * y_bytes_per_row;
+  size_t uv_bytes = alloc_height * uv_stride;
+  if (surface_.format == VideoSurface::YV12) {
+    uv_bytes /= 2;
+  }
+  uint8* data = new uint8[y_bytes + (uv_bytes * 2)];
+  if (data) {
+    surface_.planes = VideoSurface::kNumYUVPlanes;
+    COMPILE_ASSERT(0 == VideoSurface::kYPlane, y_plane_data_must_be_index_0);
+    surface_.data[VideoSurface::kYPlane] = data;
+    surface_.data[VideoSurface::kUPlane] = data + y_bytes;
+    surface_.data[VideoSurface::kVPlane] = data + y_bytes + uv_bytes;
+    surface_.strides[VideoSurface::kYPlane] = y_bytes_per_row;
+    surface_.strides[VideoSurface::kUPlane] = uv_stride;
+    surface_.strides[VideoSurface::kVPlane] = uv_stride;
+    return true;
+  }
+  NOTREACHED();
+  return false;
+}
+
+VideoFrameImpl::VideoFrameImpl(VideoSurface::Format format,
+                               size_t width,
+                               size_t height) {
+  locked_ = false;
+  memset(&surface_, 0, sizeof(surface_));
+  surface_.format = format;
+  surface_.width = width;
+  surface_.height = height;
+}
+
+VideoFrameImpl::~VideoFrameImpl() {
+  // In multi-plane allocations, only a single block of memory is allocated
+  // on the heap, and other |data| pointers point inside the same, single block
+  // so just delete index 0.
+  delete[] surface_.data[0];
+}
+
+bool VideoFrameImpl::Lock(VideoSurface* surface) {
+  DCHECK(!locked_);
+  if (locked_) {
+    memset(surface, 0, sizeof(*surface));
+    return false;
+  }
+  locked_ = true;
+  COMPILE_ASSERT(sizeof(*surface) == sizeof(surface_), surface_size_mismatch);
+  memcpy(surface, &surface_, sizeof(*surface));
+  return true;
+}
+
+void VideoFrameImpl::Unlock() {
+  DCHECK(locked_);
+  locked_ = false;
+}
+
+}  // namespace media