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// Copyright 2018 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 MEDIA_BASE_VIDEO_FRAME_LAYOUT_H_
#define MEDIA_BASE_VIDEO_FRAME_LAYOUT_H_
#include <stddef.h>
#include <stdint.h>
#include <ostream>
#include <string>
#include <utility>
#include <vector>
#include "base/optional.h"
#include "media/base/media_export.h"
#include "media/base/video_types.h"
#include "ui/gfx/geometry/size.h"
namespace media {
// A class to describes how physical buffer is allocated for video frame.
// In stores format, coded size of the frame and size of physical buffers
// which can be used to allocate buffer(s) hardware expected.
// It also stores stride (bytes per line) and offset per color plane as Plane.
// stride is to calculate each color plane's size (note that a buffer may
// contains multiple color planes.)
// offset is to describe a start point of each plane from buffer's dmabuf fd.
// Note that it is copyable.
class MEDIA_EXPORT VideoFrameLayout {
public:
// Default alignment for buffers.
// Note: This value is dependent on what's used by ffmpeg, do not change
// without inspecting av_frame_get_buffer() first.
static constexpr size_t kBufferAddressAlignment = 32;
struct Plane {
Plane() = default;
Plane(int32_t stride, size_t offset) : stride(stride), offset(offset) {}
bool operator==(const Plane& rhs) const;
bool operator!=(const Plane& rhs) const;
// Strides of a plane, typically greater or equal to the
// width of the surface divided by the horizontal sampling period. Note that
// strides can be negative if the image layout is bottom-up.
int32_t stride = 0;
// Offset of a plane, which stands for the offset of a start point of a
// color plane from a buffer fd.
size_t offset = 0;
};
// Factory functions.
// |format| and |coded_size| must be specified.
// |strides|, |planes| and |buffer_sizes| are optional, whereas they should
// be specified if |buffer_sizes| are given.
// The size of |buffer_sizes| must be less than or equal to |planes|.
// Unless they are specified, num_planes() is NumPlanes(|format|) and
// num_buffers() is 0.
// |buffer_addr_align| can be specified to request a specific buffer memory
// alignment.
// The returned base::Optional will be base::nullopt if the configured values
// are invalid.
static base::Optional<VideoFrameLayout> Create(VideoPixelFormat format,
const gfx::Size& coded_size);
// The size of |strides| must be NumPlanes(|format|). Planes' offset will be
// 0.
static base::Optional<VideoFrameLayout> CreateWithStrides(
VideoPixelFormat format,
const gfx::Size& coded_size,
std::vector<int32_t> strides,
std::vector<size_t> buffer_sizes = {});
// The size of |planes| must be NumPlanes(|format|).
static base::Optional<VideoFrameLayout> CreateWithPlanes(
VideoPixelFormat format,
const gfx::Size& coded_size,
std::vector<Plane> planes,
std::vector<size_t> buffer_sizes = {},
size_t buffer_addr_align = kBufferAddressAlignment);
VideoFrameLayout() = delete;
VideoFrameLayout(const VideoFrameLayout&);
VideoFrameLayout(VideoFrameLayout&&);
VideoFrameLayout& operator=(const VideoFrameLayout&);
~VideoFrameLayout();
static size_t NumPlanes(VideoPixelFormat format);
VideoPixelFormat format() const { return format_; }
const gfx::Size& coded_size() const { return coded_size_; }
// Return number of buffers. Note that num_planes >= num_buffers.
size_t num_buffers() const { return buffer_sizes_.size(); }
// Returns number of planes. Note that num_planes >= num_buffers.
size_t num_planes() const { return planes_.size(); }
const std::vector<Plane>& planes() const { return planes_; }
const std::vector<size_t>& buffer_sizes() const { return buffer_sizes_; }
// Returns sum of bytes of all buffers.
size_t GetTotalBufferSize() const;
bool operator==(const VideoFrameLayout& rhs) const;
bool operator!=(const VideoFrameLayout& rhs) const;
// Returns the required memory alignment for buffers.
size_t buffer_addr_align() const {
return buffer_addr_align_;
}
private:
VideoFrameLayout(VideoPixelFormat format,
const gfx::Size& coded_size,
std::vector<Plane> planes,
std::vector<size_t> buffer_sizes,
size_t buffer_addr_align);
VideoPixelFormat format_;
// Width and height of the video frame in pixels. This must include pixel
// data for the whole image; i.e. for YUV formats with subsampled chroma
// planes, in the case that the visible portion of the image does not line up
// on a sample boundary, |coded_size_| must be rounded up appropriately and
// the pixel data provided for the odd pixels.
gfx::Size coded_size_;
// Layout property for each color planes, e.g. stride and buffer offset.
std::vector<Plane> planes_;
// Vector of sizes for each buffer, typically greater or equal to the area of
// |coded_size_|.
std::vector<size_t> buffer_sizes_;
// Memory address alignment of the buffers. This is only relevant when
// allocating physical memory for the buffer, so it doesn't need to be
// serialized when frames are passed through Mojo.
size_t buffer_addr_align_;
};
// Outputs VideoFrameLayout::Plane to stream.
MEDIA_EXPORT std::ostream& operator<<(std::ostream& ostream,
const VideoFrameLayout::Plane& plane);
// Outputs VideoFrameLayout to stream.
MEDIA_EXPORT std::ostream& operator<<(std::ostream& ostream,
const VideoFrameLayout& layout);
} // namespace media
#endif // MEDIA_BASE_VIDEO_FRAME_LAYOUT_H_