Motown: Video renderer library code

mojo/services/media/common/cpp/video_packet_layout.h

+// Copyright 2016 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.
+
+#ifndef MOJO_SERVICES_MEDIA_COMMON_CPP_VIDEO_PACKET_LAYOUT_H_
+#define MOJO_SERVICES_MEDIA_COMMON_CPP_VIDEO_PACKET_LAYOUT_H_
+
+#include <memory>
+
+#include "mojo/services/media/common/interfaces/media_transport.mojom.h"
+
+namespace mojo {
+namespace media {
+
+// Describes the layout of a video packet.
+class VideoPacketLayout {
+ public:
+  static const size_t kFrameSizeAlignment = 16;
+  static const size_t kFrameSizePadding = 16;
+  static const size_t kYPlaneIndex = 0;
+  static const size_t kARGBPlaneIndex = 0;
+  static const size_t kUPlaneIndex = 1;
+  static const size_t kUVPlaneIndex = 1;
+  static const size_t kVPlaneIndex = 2;
+  static const size_t kAPlaneIndex = 3;
+  static const size_t kMaxPlaneIndex = 3;
+
+  // Width and height.
+  struct Extent {
+    Extent() : width_(0), height_(0) {}
+    Extent(int width, int height) : width_(width), height_(height) {}
+    size_t width() const { return width_; }
+    size_t height() const { return height_; }
+
+   private:
+    size_t width_;
+    size_t height_;
+  };
+
+  // Information regarding a pixel format.
+  struct PixelFormatInfo {
+    // Returns the number of bytes per element for the specified plane.
+    size_t bytes_per_element_for_plane(size_t plane) const {
+      MOJO_DCHECK(plane < plane_count_);
+      return bytes_per_element_[plane];
+    }
+
+    // Returns the sample size of the specified plane.
+    const Extent& sample_size_for_plane(size_t plane) const {
+      MOJO_DCHECK(plane < plane_count_);
+      return sample_size_[plane];
+    }
+
+    // Returns the row count for the specified plane.
+    size_t RowCount(size_t plane, size_t height) const;
+
+    // Returns the column count for the specified plane.
+    size_t ColumnCount(size_t plane, size_t width) const;
+
+    // Returns the number of bytes per row for the specified plane.
+    size_t BytesPerRow(size_t plane, size_t width) const;
+
+    // Calculates an aligned size from an unaligned size.
+    Extent AlignedSize(const Extent& unaligned_size) const;
+
+    // Determines a common alignment for all planes.
+    Extent CommonAlignment() const;
+
+    const size_t plane_count_;
+    const size_t bytes_per_element_[kMaxPlaneIndex + 1];
+    const Extent sample_size_[kMaxPlaneIndex + 1];
+  };
+
+  // Gets information for the specified pixel format.
+  static const PixelFormatInfo& InfoForPixelFormat(PixelFormat pixel_format);
+
+  VideoPacketLayout();
+
+  VideoPacketLayout(PixelFormat pixel_format,
+                    uint32_t width,
+                    uint32_t height,
+                    uint32_t coded_width,
+                    uint32_t coded_height);
+
+  ~VideoPacketLayout();
+
+  PixelFormat pixel_format() const { return pixel_format_; }
+
+  uint32_t width() const { return width_; }
+
+  uint32_t height() const { return height_; }
+
+  uint32_t coded_width() const { return coded_width_; }
+
+  uint32_t coded_height() const { return coded_height_; }
+
+  size_t plane_count() const { return plane_count_; }
+
+  size_t size() const { return size_; }
+
+  size_t line_stride_for_plane(size_t plane) {
+    MOJO_DCHECK(plane < plane_count_);
+    return line_stride_[plane];
+  }
+
+  size_t plane_offset_for_plane(size_t plane) {
+    MOJO_DCHECK(plane < plane_count_);
+    return plane_offset_[plane];
+  }
+
+  const PixelFormatInfo& GetPixelFormatInfo() const {
+    return InfoForPixelFormat(pixel_format_);
+  }
+
+ private:
+  PixelFormat pixel_format_;
+  uint32_t width_;
+  uint32_t height_;
+  uint32_t coded_width_;
+  uint32_t coded_height_;
+  size_t plane_count_;
+  size_t line_stride_[kMaxPlaneIndex + 1];
+  size_t plane_offset_[kMaxPlaneIndex + 1];
+  size_t size_;
+};
+
+}  // namespace media
+}  // namespace mojo
+
+#endif  // MOJO_SERVICES_MEDIA_COMMON_CPP_VIDEO_PACKET_LAYOUT_H_