// Copyright (c) 2012 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_H_
#define MEDIA_BASE_VIDEO_FRAME_H_

#include <stddef.h>
#include <stdint.h>

#include <memory>
#include <string>
#include <utility>
#include <vector>

#include "base/callback.h"
#include "base/check_op.h"
#include "base/hash/md5.h"
#include "base/memory/free_deleter.h"
#include "base/memory/ref_counted.h"
#include "base/memory/unsafe_shared_memory_region.h"
#include "base/synchronization/lock.h"
#include "base/thread_annotations.h"
#include "base/unguessable_token.h"
#include "build/build_config.h"
#include "gpu/command_buffer/common/mailbox_holder.h"
#include "gpu/ipc/common/vulkan_ycbcr_info.h"
#include "media/base/video_frame_layout.h"
#include "media/base/video_frame_metadata.h"
#include "media/base/video_types.h"
#include "third_party/abseil-cpp/absl/types/optional.h"
#include "ui/gfx/color_space.h"
#include "ui/gfx/geometry/rect.h"
#include "ui/gfx/geometry/size.h"
#include "ui/gfx/hdr_metadata.h"

#if defined(OS_MAC)
#include <CoreVideo/CVPixelBuffer.h>
#include "base/mac/scoped_cftyperef.h"
#endif  // defined(OS_MAC)

#if defined(OS_LINUX) || defined(OS_CHROMEOS)
#include "base/files/scoped_file.h"
#endif  // defined(OS_LINUX) || defined(OS_CHROMEOS)

namespace gfx {
class GpuMemoryBuffer;
struct GpuMemoryBufferHandle;
}

namespace media {

class MEDIA_EXPORT VideoFrame : public base::RefCountedThreadSafe<VideoFrame> {
 public:
  enum {
    kFrameSizeAlignment = 16,
    kFrameSizePadding = 16,

    kFrameAddressAlignment = VideoFrameLayout::kBufferAddressAlignment
  };

  enum {
    kMaxPlanes = 4,

    kYPlane = 0,
    kARGBPlane = kYPlane,
    kUPlane = 1,
    kUVPlane = kUPlane,
    kVPlane = 2,
    kAPlane = 3,
  };

  // Defines the pixel storage type. Differentiates between directly accessible
  // |data_| and pixels that are only indirectly accessible and not via mappable
  // memory.
  // Note that VideoFrames of any StorageType can also have Texture backing,
  // with "classical" GPU Driver-only textures identified as STORAGE_OPAQUE.
  enum StorageType {
    STORAGE_UNKNOWN = 0,
    STORAGE_OPAQUE = 1,  // We don't know how VideoFrame's pixels are stored.
    STORAGE_UNOWNED_MEMORY = 2,  // External, non owned data pointers.
    STORAGE_OWNED_MEMORY = 3,  // VideoFrame has allocated its own data buffer.
    STORAGE_SHMEM = 4,         // Backed by unsafe (writable) shared memory.
#if defined(OS_LINUX) || defined(OS_CHROMEOS)
    // TODO(mcasas): Consider turning this type into STORAGE_NATIVE
    // based on the idea of using this same enum value for both DMA
    // buffers on Linux and CVPixelBuffers on Mac (which currently use
    // STORAGE_UNOWNED_MEMORY) and handle it appropriately in all cases.
    STORAGE_DMABUFS = 5,  // Each plane is stored into a DmaBuf.
#endif
    // Backed by a mojo shared buffer. This should only be used by the
    // MojoSharedBufferVideoFrame subclass.
    STORAGE_MOJO_SHARED_BUFFER = 6,
    STORAGE_GPU_MEMORY_BUFFER = 7,
    STORAGE_LAST = STORAGE_GPU_MEMORY_BUFFER,
  };

  // CB to be called on the mailbox backing this frame and its GpuMemoryBuffers
  // (if they exist) when the frame is destroyed.
  using ReleaseMailboxCB = base::OnceCallback<void(const gpu::SyncToken&)>;
  using ReleaseMailboxAndGpuMemoryBufferCB =
      base::OnceCallback<void(const gpu::SyncToken&,
                              std::unique_ptr<gfx::GpuMemoryBuffer>)>;

  // Interface representing client operations on a SyncToken, i.e. insert one in
  // the GPU Command Buffer and wait for it.
  class SyncTokenClient {
   public:
    SyncTokenClient() = default;
    SyncTokenClient(const SyncTokenClient&) = delete;
    SyncTokenClient& operator=(const SyncTokenClient&) = delete;

    virtual void GenerateSyncToken(gpu::SyncToken* sync_token) = 0;
    virtual void WaitSyncToken(const gpu::SyncToken& sync_token) = 0;

   protected:
    virtual ~SyncTokenClient() = default;
  };

  VideoFrame() = delete;
  VideoFrame(const VideoFrame&) = delete;
  VideoFrame& operator=(const VideoFrame&) = delete;

  // Returns true if size is valid for a VideoFrame.
  static bool IsValidSize(const gfx::Size& coded_size,
                          const gfx::Rect& visible_rect,
                          const gfx::Size& natural_size);

  // Returns true if and only if the |size| is within limits, i.e., neither
  // dimension exceeds limits::kMaxDimension and the total area doesn't exceed
  // limits::kMaxCanvas. Prefer the overload that accepts the |coded_size|,
  // |visible_rect|, and |natural_size| if trying to validate the VideoFrame.
  static bool IsValidCodedSize(const gfx::Size& size);

  // Returns true if frame configuration is valid.
  static bool IsValidConfig(VideoPixelFormat format,
                            StorageType storage_type,
                            const gfx::Size& coded_size,
                            const gfx::Rect& visible_rect,
                            const gfx::Size& natural_size);

  // Creates a new frame in system memory with given parameters. Buffers for the
  // frame are allocated but not initialized. The caller must not make
  // assumptions about the actual underlying size(s), but check the returned
  // VideoFrame instead.
  static scoped_refptr<VideoFrame> CreateFrame(VideoPixelFormat format,
                                               const gfx::Size& coded_size,
                                               const gfx::Rect& visible_rect,
                                               const gfx::Size& natural_size,
                                               base::TimeDelta timestamp);

  // Used by Chromecast only.
  // Create a new frame that doesn't contain any valid video content. This frame
  // is meant to be sent to compositor to inform that the compositor should
  // punch a transparent hole so the video underlay will be visible.
  static scoped_refptr<VideoFrame> CreateVideoHoleFrame(
      const base::UnguessableToken& overlay_plane_id,
      const gfx::Size& natural_size,
      base::TimeDelta timestamp);

  // Offers the same functionality as CreateFrame, and additionally zeroes out
  // the initial allocated buffers.
  static scoped_refptr<VideoFrame> CreateZeroInitializedFrame(
      VideoPixelFormat format,
      const gfx::Size& coded_size,
      const gfx::Rect& visible_rect,
      const gfx::Size& natural_size,
      base::TimeDelta timestamp);

  // Creates a new frame in system memory with given parameters. Buffers for the
  // frame are allocated but not initialized. The caller should specify the
  // physical buffer size and strides if needed in |layout| parameter.
  static scoped_refptr<VideoFrame> CreateFrameWithLayout(
      const VideoFrameLayout& layout,
      const gfx::Rect& visible_rect,
      const gfx::Size& natural_size,
      base::TimeDelta timestamp,
      bool zero_initialize_memory);

  // Wraps a set of native textures with a VideoFrame.
  // |mailbox_holders_release_cb| will be called with a sync token as the
  // argument when the VideoFrame is to be destroyed.
  static scoped_refptr<VideoFrame> WrapNativeTextures(
      VideoPixelFormat format,
      const gpu::MailboxHolder (&mailbox_holder)[kMaxPlanes],
      ReleaseMailboxCB mailbox_holders_release_cb,
      const gfx::Size& coded_size,
      const gfx::Rect& visible_rect,
      const gfx::Size& natural_size,
      base::TimeDelta timestamp);

  // Wraps packed image data residing in a memory buffer with a VideoFrame.
  // The image data resides in |data| and is assumed to be packed tightly in a
  // buffer of logical dimensions |coded_size| with the appropriate bit depth
  // and plane count as given by |format|. Returns NULL on failure.
  static scoped_refptr<VideoFrame> WrapExternalData(
      VideoPixelFormat format,
      const gfx::Size& coded_size,
      const gfx::Rect& visible_rect,
      const gfx::Size& natural_size,
      uint8_t* data,
      size_t data_size,
      base::TimeDelta timestamp);

  static scoped_refptr<VideoFrame> WrapExternalDataWithLayout(
      const VideoFrameLayout& layout,
      const gfx::Rect& visible_rect,
      const gfx::Size& natural_size,
      uint8_t* data,
      size_t data_size,
      base::TimeDelta timestamp);

  // Wraps external YUV data of the given parameters with a VideoFrame.
  // The returned VideoFrame does not own the data passed in.
  static scoped_refptr<VideoFrame> WrapExternalYuvData(
      VideoPixelFormat format,
      const gfx::Size& coded_size,
      const gfx::Rect& visible_rect,
      const gfx::Size& natural_size,
      int32_t y_stride,
      int32_t u_stride,
      int32_t v_stride,
      uint8_t* y_data,
      uint8_t* u_data,
      uint8_t* v_data,
      base::TimeDelta timestamp);

  // Wraps external YUV data with VideoFrameLayout. The returned VideoFrame does
  // not own the data passed in.
  static scoped_refptr<VideoFrame> WrapExternalYuvDataWithLayout(
      const VideoFrameLayout& layout,
      const gfx::Rect& visible_rect,
      const gfx::Size& natural_size,
      uint8_t* y_data,
      uint8_t* u_data,
      uint8_t* v_data,
      base::TimeDelta timestamp);

  // Wraps external YUVA data of the given parameters with a VideoFrame.
  // The returned VideoFrame does not own the data passed in.
  static scoped_refptr<VideoFrame> WrapExternalYuvaData(
      VideoPixelFormat format,
      const gfx::Size& coded_size,
      const gfx::Rect& visible_rect,
      const gfx::Size& natural_size,
      int32_t y_stride,
      int32_t u_stride,
      int32_t v_stride,
      int32_t a_stride,
      uint8_t* y_data,
      uint8_t* u_data,
      uint8_t* v_data,
      uint8_t* a_data,
      base::TimeDelta timestamp);

  // Wraps external NV12 data of the given parameters with a VideoFrame.
  // The returned VideoFrame does not own the data passed in.
  static scoped_refptr<VideoFrame> WrapExternalYuvData(
      VideoPixelFormat format,
      const gfx::Size& coded_size,
      const gfx::Rect& visible_rect,
      const gfx::Size& natural_size,
      int32_t y_stride,
      int32_t uv_stride,
      uint8_t* y_data,
      uint8_t* uv_data,
      base::TimeDelta timestamp);

  // Wraps |gpu_memory_buffer| along with the mailboxes created from
  // |gpu_memory_buffer|. This will transfer ownership of |gpu_memory_buffer|
  // to the returned VideoFrame. |mailbox_holder_and_gmb_release_cb| will be
  // called with a sync token and with |gpu_memory_buffer| as arguments when the
  // VideoFrame is to be destroyed.
  static scoped_refptr<VideoFrame> WrapExternalGpuMemoryBuffer(
      const gfx::Rect& visible_rect,
      const gfx::Size& natural_size,
      std::unique_ptr<gfx::GpuMemoryBuffer> gpu_memory_buffer,
      const gpu::MailboxHolder (&mailbox_holders)[kMaxPlanes],
      ReleaseMailboxAndGpuMemoryBufferCB mailbox_holder_and_gmb_release_cb,
      base::TimeDelta timestamp);

#if defined(OS_LINUX) || defined(OS_CHROMEOS)
  // Wraps provided dmabufs
  // (https://www.kernel.org/doc/html/latest/driver-api/dma-buf.html) with a
  // VideoFrame. The frame will take ownership of |dmabuf_fds|, and will
  // automatically close() them on destruction. Callers can call
  // media::DuplicateFDs() if they need to retain a copy of the FDs for
  // themselves. Note that the FDs are consumed even in case of failure.
  // The image data is only accessible via dmabuf fds, which are usually passed
  // directly to a hardware device and/or to another process, or can also be
  // mapped via mmap() for CPU access.
  // Returns NULL on failure.
  static scoped_refptr<VideoFrame> WrapExternalDmabufs(
      const VideoFrameLayout& layout,
      const gfx::Rect& visible_rect,
      const gfx::Size& natural_size,
      std::vector<base::ScopedFD> dmabuf_fds,
      base::TimeDelta timestamp);
#endif

#if defined(OS_MAC)
  // Wraps a provided CVPixelBuffer with a VideoFrame. The pixel buffer is
  // retained for the lifetime of the VideoFrame and released upon destruction.
  // The image data is only accessible via the pixel buffer, which could be
  // backed by an IOSurface from another process. All the attributes of the
  // VideoFrame are derived from the pixel buffer, with the exception of the
  // timestamp. If information is missing or is incompatible (for example, a
  // pixel format that has no VideoFrame match), NULL is returned.
  // http://crbug.com/401308
  static scoped_refptr<VideoFrame> WrapCVPixelBuffer(
      CVPixelBufferRef cv_pixel_buffer,
      base::TimeDelta timestamp);

  // Wraps a provided IOSurface with a VideoFrame. The IOSurface is retained
  // and locked for the lifetime of the VideoFrame. This is for unaccelerated
  // (CPU-only) access to the IOSurface, and is not efficient. It is the path
  // that video capture uses when hardware acceleration is disabled.
  // https://crbug.com/1125879
  static scoped_refptr<VideoFrame> WrapUnacceleratedIOSurface(
      gfx::GpuMemoryBufferHandle handle,
      const gfx::Rect& visible_rect,
      base::TimeDelta timestamp);
#endif

  // Wraps |frame|. |visible_rect| must be a sub rect within
  // frame->visible_rect().
  static scoped_refptr<VideoFrame> WrapVideoFrame(
      scoped_refptr<VideoFrame> frame,
      VideoPixelFormat format,
      const gfx::Rect& visible_rect,
      const gfx::Size& natural_size);

  // Creates a frame which indicates end-of-stream.
  static scoped_refptr<VideoFrame> CreateEOSFrame();

  // Allocates YV12 frame based on |size|, and sets its data to the YUV(y,u,v).
  static scoped_refptr<VideoFrame> CreateColorFrame(const gfx::Size& size,
                                                    uint8_t y,
                                                    uint8_t u,
                                                    uint8_t v,
                                                    base::TimeDelta timestamp);

  // Allocates YV12 frame based on |size|, and sets its data to the YUV
  // equivalent of RGB(0,0,0).
  static scoped_refptr<VideoFrame> CreateBlackFrame(const gfx::Size& size);

  // Allocates YV12A frame based on |size|, and sets its data to the YUVA
  // equivalent of RGBA(0,0,0,0).
  static scoped_refptr<VideoFrame> CreateTransparentFrame(
      const gfx::Size& size);

  static size_t NumPlanes(VideoPixelFormat format);

  // Returns the required allocation size for a (tightly packed) frame of the
  // given coded size and format.
  static size_t AllocationSize(VideoPixelFormat format,
                               const gfx::Size& coded_size);

  // Returns |dimensions| adjusted to appropriate boundaries based on |format|.
  static gfx::Size DetermineAlignedSize(VideoPixelFormat format,
                                        const gfx::Size& dimensions);

  // Returns the plane gfx::Size (in bytes) for a plane of the given coded size
  // and format.
  static gfx::Size PlaneSize(VideoPixelFormat format,
                             size_t plane,
                             const gfx::Size& coded_size);

  // Returns the plane gfx::Size (in samples) for a plane of the given coded
  // size and format.
  static gfx::Size PlaneSizeInSamples(VideoPixelFormat format,
                                      size_t plane,
                                      const gfx::Size& coded_size);

  // Returns horizontal bits per pixel for given |plane| and |format|.
  static int PlaneHorizontalBitsPerPixel(VideoPixelFormat format, size_t plane);

  // Returns bits per pixel for given |plane| and |format|.
  static int PlaneBitsPerPixel(VideoPixelFormat format, size_t plane);

  // Returns the number of bytes per row for the given plane, format, and width.
  // The width may be aligned to format requirements.
  static size_t RowBytes(size_t plane, VideoPixelFormat format, int width);

  // Returns the number of bytes per element for given |plane| and |format|.
  static int BytesPerElement(VideoPixelFormat format, size_t plane);

  // Calculates strides for each plane based on |format| and |coded_size|.
  static std::vector<int32_t> ComputeStrides(VideoPixelFormat format,
                                             const gfx::Size& coded_size);

  // Returns the number of rows for the given plane, format, and height.
  // The height may be aligned to format requirements.
  static size_t Rows(size_t plane, VideoPixelFormat format, int height);

  // Returns the number of columns for the given plane, format, and width.
  // The width may be aligned to format requirements.
  static size_t Columns(size_t plane, VideoPixelFormat format, int width);

  // Used to keep a running hash of seen frames.  Expects an initialized MD5
  // context.  Calls MD5Update with the context and the contents of the frame.
  static void HashFrameForTesting(base::MD5Context* context,
                                  const VideoFrame& frame);

  // Returns true if |frame| is accesible mapped in the VideoFrame memory space.
  // static
  static bool IsStorageTypeMappable(VideoFrame::StorageType storage_type);

  // Returns true if |plane| is a valid plane index for the given |format|.
  static bool IsValidPlane(VideoPixelFormat format, size_t plane);

  // Returns the pixel size of each subsample for a given |plane| and |format|.
  // E.g. 2x2 for the U-plane in PIXEL_FORMAT_I420.
  static gfx::Size SampleSize(VideoPixelFormat format, size_t plane);

  // Returns a human readable string of StorageType.
  static std::string StorageTypeToString(VideoFrame::StorageType storage_type);

  // A video frame wrapping external data may be backed by an unsafe shared
  // memory region. These methods are used to appropriately transform a
  // VideoFrame created with WrapExternalData, WrapExternalYuvaData, etc. The
  // storage type of the Video Frame will be changed to STORAGE_SHM. Once the
  // backing of a VideoFrame is set, it cannot be changed.
  //
  // The region is NOT owned by the video frame. Both the region and its
  // associated mapping must outlive this instance.
  void BackWithSharedMemory(const base::UnsafeSharedMemoryRegion* region);

  // As above, but the VideoFrame owns the shared memory region as well as the
  // mapping. They will be destroyed with their VideoFrame.
  void BackWithOwnedSharedMemory(base::UnsafeSharedMemoryRegion region,
                                 base::WritableSharedMemoryMapping mapping);

  // Valid for shared memory backed VideoFrames.
  const base::UnsafeSharedMemoryRegion* shm_region() {
    DCHECK(IsValidSharedMemoryFrame());
    DCHECK(storage_type_ == STORAGE_SHMEM);
    return shm_region_;
  }

  // Returns true if |frame| is accessible and mapped in the VideoFrame memory
  // space. If false, clients should refrain from accessing data(),
  // visible_data() etc.
  bool IsMappable() const;

  // Returns true if |frame| has textures with any StorageType and should not be
  // accessed via data(), visible_data() etc.
  bool HasTextures() const;

  // Returns the number of native textures.
  size_t NumTextures() const;

  // Returns true if the video frame is backed with GpuMemoryBuffer.
  bool HasGpuMemoryBuffer() const;

  // Gets the GpuMemoryBuffer backing the VideoFrame.
  gfx::GpuMemoryBuffer* GetGpuMemoryBuffer() const;

  // Returns true if the video frame was created with the given parameters.
  bool IsSameAllocation(VideoPixelFormat format,
                        const gfx::Size& coded_size,
                        const gfx::Rect& visible_rect,
                        const gfx::Size& natural_size) const;

  // Returns the color space of this frame's content.
  gfx::ColorSpace ColorSpace() const;
  void set_color_space(const gfx::ColorSpace& color_space) {
    color_space_ = color_space;
  }

  const absl::optional<gfx::HDRMetadata>& hdr_metadata() const {
    return hdr_metadata_;
  }

  void set_hdr_metadata(const absl::optional<gfx::HDRMetadata>& hdr_metadata) {
    hdr_metadata_ = hdr_metadata;
  }

  const VideoFrameLayout& layout() const { return layout_; }

  VideoPixelFormat format() const { return layout_.format(); }
  StorageType storage_type() const { return storage_type_; }

  // The full dimensions of the video frame data.
  const gfx::Size& coded_size() const { return layout_.coded_size(); }
  // A subsection of [0, 0, coded_size().width(), coded_size.height()]. This
  // can be set to "soft-apply" a cropping. It determines the pointers into
  // the data returned by visible_data().
  const gfx::Rect& visible_rect() const { return visible_rect_; }
  // Specifies that the |visible_rect| section of the frame is supposed to be
  // scaled to this size when being presented. This can be used to represent
  // anamorphic frames, or to "soft-apply" any custom scaling.
  const gfx::Size& natural_size() const { return natural_size_; }

  int stride(size_t plane) const {
    DCHECK(IsValidPlane(format(), plane));
    DCHECK_LT(plane, layout_.num_planes());
    return layout_.planes()[plane].stride;
  }

  // Returns the number of bytes per row and number of rows for a given plane.
  //
  // As opposed to stride(), row_bytes() refers to the bytes representing
  // frame data scanlines (coded_size.width() pixels, without stride padding).
  int row_bytes(size_t plane) const;
  int rows(size_t plane) const;

  // Returns the number of columns for a given plane.
  int columns(size_t plane) const;

  // Returns pointer to the buffer for a given plane, if this is an
  // IsMappable() frame type. The memory is owned by VideoFrame object and must
  // not be freed by the caller.
  const uint8_t* data(size_t plane) const {
    DCHECK(IsValidPlane(format(), plane));
    DCHECK(IsMappable());
    return data_[plane];
  }
  uint8_t* data(size_t plane) {
    DCHECK(IsValidPlane(format(), plane));
    DCHECK(IsMappable());
    return data_[plane];
  }

  const absl::optional<gpu::VulkanYCbCrInfo>& ycbcr_info() const {
    return wrapped_frame_ ? wrapped_frame_->ycbcr_info() : ycbcr_info_;
  }

  // Returns pointer to the data in the visible region of the frame, for
  // IsMappable() storage types. The returned pointer is offsetted into the
  // plane buffer specified by visible_rect().origin(). Memory is owned by
  // VideoFrame object and must not be freed by the caller.
  const uint8_t* visible_data(size_t plane) const;
  uint8_t* visible_data(size_t plane);

  // Returns a mailbox holder for a given texture.
  // Only valid to call if this is a NATIVE_TEXTURE frame. Before using the
  // mailbox, the caller must wait for the included sync point.
  const gpu::MailboxHolder& mailbox_holder(size_t texture_index) const;

#if defined(OS_LINUX) || defined(OS_CHROMEOS)
  // Returns a vector containing the backing DmaBufs for this frame. The number
  // of returned DmaBufs will be equal or less than the number of planes of
  // the frame. If there are less, this means that the last FD contains the
  // remaining planes.
  // Note that the returned FDs are still owned by the VideoFrame. This means
  // that the caller shall not close them, or use them after the VideoFrame is
  // destroyed. For such use cases, use media::DuplicateFDs() to obtain your
  // own copy of the FDs.
  const std::vector<base::ScopedFD>& DmabufFds() const;

  // Returns true if |frame| has DmaBufs.
  bool HasDmaBufs() const;

  // Returns true if both VideoFrames are backed by DMABUF memory and point
  // to the same set of DMABUFs, meaning that both frames use the same memory.
  bool IsSameDmaBufsAs(const VideoFrame& frame) const;
#endif

#if defined(OS_MAC)
  // Returns the backing CVPixelBuffer, if present.
  CVPixelBufferRef CvPixelBuffer() const;
#endif

  // Sets the mailbox (and GpuMemoryBuffer, if desired) release callback.
  //
  // The callback may be run from ANY THREAD, and so it is up to the client to
  // ensure thread safety.
  //
  // WARNING: This method is not thread safe; it should only be called if you
  // are still the only owner of this VideoFrame.
  void SetReleaseMailboxCB(ReleaseMailboxCB release_mailbox_cb);
  void SetReleaseMailboxAndGpuMemoryBufferCB(
      ReleaseMailboxAndGpuMemoryBufferCB release_mailbox_cb);

  // Tests whether a mailbox release callback is configured.
  bool HasReleaseMailboxCB() const;

  // Adds a callback to be run when the VideoFrame is about to be destroyed.
  // The callback may be run from ANY THREAD, and so it is up to the client to
  // ensure thread safety.  Although read-only access to the members of this
  // VideoFrame is permitted while the callback executes (including
  // VideoFrameMetadata), clients should not assume the data pointers are
  // valid.
  void AddDestructionObserver(base::OnceClosure callback);

  // Returns a dictionary of optional metadata.  This contains information
  // associated with the frame that downstream clients might use for frame-level
  // logging, quality/performance optimizations, signaling, etc.
  //
  // TODO(miu): Move some of the "extra" members of VideoFrame (below) into
  // here as a later clean-up step.
  const VideoFrameMetadata& metadata() const { return metadata_; }
  VideoFrameMetadata& metadata() { return metadata_; }
  void set_metadata(const VideoFrameMetadata& metadata) {
    metadata_ = metadata;
  }

  // Resets |metadata_|.
  void clear_metadata() { set_metadata(VideoFrameMetadata()); }

  // The time span between the current frame and the first frame of the stream.
  // This is the media timestamp, and not the reference time.
  // See VideoFrameMetadata::REFERENCE_TIME for details.
  base::TimeDelta timestamp() const { return timestamp_; }
  void set_timestamp(base::TimeDelta timestamp) { timestamp_ = timestamp; }

  // It uses |client| to insert a new sync token and potentially waits on an
  // older sync token. The final sync point will be used to release this
  // VideoFrame. Also returns the new sync token.
  // This method is thread safe. Both blink and compositor threads can call it.
  gpu::SyncToken UpdateReleaseSyncToken(SyncTokenClient* client);

  // Similar to UpdateReleaseSyncToken() but operates on the gpu::SyncToken for
  // each plane. This should only be called when a VideoFrame has a single
  // owner. I.e., before it has been vended after creation.
  gpu::SyncToken UpdateMailboxHolderSyncToken(size_t plane,
                                              SyncTokenClient* client);

  // Returns a human-readable string describing |*this|.
  std::string AsHumanReadableString() const;

  // Unique identifier for this video frame; generated at construction time and
  // guaranteed to be unique within a single process.
  int unique_id() const { return unique_id_; }

  // Returns the number of bits per channel.
  size_t BitDepth() const;

  // Provide the sampler conversion information for the frame.
  void set_ycbcr_info(const absl::optional<gpu::VulkanYCbCrInfo>& ycbcr_info) {
    ycbcr_info_ = ycbcr_info;
  }

 protected:
  friend class base::RefCountedThreadSafe<VideoFrame>;

  enum class FrameControlType {
    kNone,
    kEos,
    kVideoHole,
  };

  // Clients must use the static factory/wrapping methods to create a new frame.
  // Derived classes should create their own factory/wrapping methods, and use
  // this constructor to do basic initialization.
  VideoFrame(const VideoFrameLayout& layout,
             StorageType storage_type,
             const gfx::Rect& visible_rect,
             const gfx::Size& natural_size,
             base::TimeDelta timestamp,
             FrameControlType frame_control_type = FrameControlType::kNone);
  virtual ~VideoFrame();

  // Creates a summary of the configuration settings provided as parameters.
  static std::string ConfigToString(const VideoPixelFormat format,
                                    const VideoFrame::StorageType storage_type,
                                    const gfx::Size& coded_size,
                                    const gfx::Rect& visible_rect,
                                    const gfx::Size& natural_size);

  void set_data(size_t plane, uint8_t* ptr) {
    DCHECK(IsValidPlane(format(), plane));
    DCHECK(ptr);
    data_[plane] = ptr;
  }

 private:
  // The constructor of VideoFrame should use IsValidConfigInternal()
  // instead of the public IsValidConfig() to check the config, because we can
  // create special video frames that won't pass the check by IsValidConfig().
  static bool IsValidConfigInternal(VideoPixelFormat format,
                                    FrameControlType frame_control_type,
                                    const gfx::Size& coded_size,
                                    const gfx::Rect& visible_rect,
                                    const gfx::Size& natural_size);

  static scoped_refptr<VideoFrame> CreateFrameInternal(
      VideoPixelFormat format,
      const gfx::Size& coded_size,
      const gfx::Rect& visible_rect,
      const gfx::Size& natural_size,
      base::TimeDelta timestamp,
      bool zero_initialize_memory);

  // Return the alignment for the whole frame, calculated as the max of the
  // alignment for each individual plane.
  static gfx::Size CommonAlignment(VideoPixelFormat format);

  // Tries to allocate the requisite amount of memory for this frame. Returns
  // false if this would cause an out of memory error.
  WARN_UNUSED_RESULT bool AllocateMemory(bool zero_initialize_memory);

  // Calculates plane size.
  // It first considers buffer size layout_ object provides. If layout's
  // number of buffers equals to number of planes, and buffer size is assigned
  // (non-zero), it returns buffers' size.
  // Otherwise, it uses the first (num_buffers - 1) assigned buffers' size as
  // plane size. Then for the rest unassigned planes, calculates their size
  // based on format, coded size and stride for the plane.
  std::vector<size_t> CalculatePlaneSize() const;

  // Returns true iff the frame has a shared memory storage type, and the
  // associated regions are valid.
  bool IsValidSharedMemoryFrame() const;

  // VideFrameLayout (includes format, coded_size, and strides).
  const VideoFrameLayout layout_;

  // Set by WrapVideoFrame to soft-apply a new set of format, visible rectangle,
  // and natural size on |wrapped_frame_|
  scoped_refptr<VideoFrame> wrapped_frame_;

  // Storage type for the different planes.
  StorageType storage_type_;  // TODO(mcasas): make const

  // Width, height, and offsets of the visible portion of the video frame. Must
  // be a subrect of |coded_size_|. Can be odd with respect to the sample
  // boundaries, e.g. for formats with subsampled chroma.
  const gfx::Rect visible_rect_;

  // Width and height of the visible portion of the video frame
  // (|visible_rect_.size()|) with aspect ratio taken into account.
  const gfx::Size natural_size_;

  // Array of data pointers to each plane.
  // TODO(mcasas): we don't know on ctor if we own |data_| or not. Change
  // to std::unique_ptr<uint8_t, AlignedFreeDeleter> after refactoring
  // VideoFrame.
  uint8_t* data_[kMaxPlanes];

  // Native texture mailboxes, if this is a IsTexture() frame.
  gpu::MailboxHolder mailbox_holders_[kMaxPlanes];
  ReleaseMailboxAndGpuMemoryBufferCB mailbox_holders_and_gmb_release_cb_;

  // Shared memory handle, if this frame is STORAGE_SHMEM.  The region pointed
  // to is unowned.
  const base::UnsafeSharedMemoryRegion* shm_region_ = nullptr;

  // Used if this is a STORAGE_SHMEM frame with owned shared memory. In that
  // case, shm_region_ will refer to this region.
  base::UnsafeSharedMemoryRegion owned_shm_region_;
  base::WritableSharedMemoryMapping owned_shm_mapping_;

  // GPU memory buffer, if this frame is STORAGE_GPU_MEMORY_BUFFER.
  std::unique_ptr<gfx::GpuMemoryBuffer> gpu_memory_buffer_;

#if defined(OS_LINUX) || defined(OS_CHROMEOS)
  class DmabufHolder;

  // Dmabufs for the frame, used when storage is STORAGE_DMABUFS. Size is either
  // equal or less than the number of planes of the frame. If it is less, then
  // the memory area represented by the last FD contains the remaining planes.
  // If a STORAGE_DMABUFS frame is wrapped into another, the wrapping frame
  // will get an extra reference to the FDs (i.e. no duplication is involved).
  // This makes it possible to test whether two VideoFrame instances point to
  // the same DMABUF memory by testing for
  // (&vf1->DmabufFds() == &vf2->DmabufFds()).
  scoped_refptr<DmabufHolder> dmabuf_fds_;
#endif

#if defined(OS_MAC)
  // CVPixelBuffer, if this frame is wrapping one.
  base::ScopedCFTypeRef<CVPixelBufferRef> cv_pixel_buffer_;
#endif

  std::vector<base::OnceClosure> done_callbacks_;

  base::TimeDelta timestamp_;

  base::Lock release_sync_token_lock_;
  gpu::SyncToken release_sync_token_ GUARDED_BY(release_sync_token_lock_);

  VideoFrameMetadata metadata_;

  // Generated at construction time.
  const int unique_id_;

  gfx::ColorSpace color_space_;
  absl::optional<gfx::HDRMetadata> hdr_metadata_;

  // Sampler conversion information which is used in vulkan context for android.
  absl::optional<gpu::VulkanYCbCrInfo> ycbcr_info_;

  // Allocation which makes up |data_| planes for self-allocated frames.
  std::unique_ptr<uint8_t, base::FreeDeleter> private_data_;
};

}  // namespace media

#endif  // MEDIA_BASE_VIDEO_FRAME_H_