Add a GpuMemoryBuffer pool that creates hardware backed VideoFrames.

media/video/gpu_memory_buffer_video_frame_pool.cc

+// Copyright 2015 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/video/gpu_memory_buffer_video_frame_pool.h"
+
+#include <GLES2/gl2.h>
+#include <GLES2/gl2ext.h>
+
+#include <list>
+#include <utility>
+
+#include "base/bind.h"
+#include "base/containers/stack_container.h"
+#include "base/location.h"
+#include "base/memory/linked_ptr.h"
+#include "base/single_thread_task_runner.h"
+#include "base/trace_event/trace_event.h"
+#include "gpu/command_buffer/client/gles2_interface.h"
+#include "media/renderers/gpu_video_accelerator_factories.h"
+
+namespace media {
+
+// Implementation of a pool of GpuMemoryBuffers used to back VideoFrames.
+class GpuMemoryBufferVideoFramePool::PoolImpl
+    : public base::RefCountedThreadSafe<
+          GpuMemoryBufferVideoFramePool::PoolImpl> {
+ public:
+  // |task_runner| is associated to the thread where the context of
+  // GLES2Interface returned by |gpu_factories| lives.
+  // |gpu_factories| is an interface to GPU related operation and can be
+  // null.
+  PoolImpl(const scoped_refptr<base::SingleThreadTaskRunner>& task_runner,
+           const scoped_refptr<GpuVideoAcceleratorFactories>& gpu_factories)
+      : task_runner_(task_runner), gpu_factories_(gpu_factories) {}
+
+  // Takes a software VideoFrame and returns a VideoFrame backed by native
+  // textures if possible.
+  // The data contained in video_frame is copied into the returned frame.
+  scoped_refptr<VideoFrame> CreateHardwareFrame(
+      const scoped_refptr<VideoFrame>& video_frame);
+
+ private:
+  friend class base::RefCountedThreadSafe<
+      GpuMemoryBufferVideoFramePool::PoolImpl>;
+  ~PoolImpl();
+
+  // Resource to represent a plane.
+  struct PlaneResource {
+    gfx::Size size;
+    scoped_ptr<gfx::GpuMemoryBuffer> gpu_memory_buffer;
+    unsigned texture_id = 0u;
+    unsigned image_id = 0u;
+    gpu::Mailbox mailbox;
+  };
+
+  // All the resources needed to compose a frame.
+  struct FrameResources {
+    FrameResources(VideoFrame::Format format, const gfx::Size& size)
+        : format(format), size(size) {}
+    bool in_use = true;
+    VideoFrame::Format format;
+    gfx::Size size;
+    PlaneResource plane_resources[VideoFrame::kMaxPlanes];
+  };
+
+  // Return true if |resources| can be used to represent a frame for
+  // specific |format| and |size|.
+  static bool AreFrameResourcesCompatible(const FrameResources* resources,
+                                          const gfx::Size& size,
+                                          VideoFrame::Format format) {
+    return size == resources->size && format == resources->format;
+  }
+
+  // Get the resources needed for a frame out of the pool, or create them if
+  // necessary.
+  // This also drops the LRU resources that can't be reuse for this frame.
+  FrameResources* GetOrCreateFrameResources(const gfx::Size& size,
+                                            VideoFrame::Format format);
+
+  // Callback called when a VideoFrame generated with GetFrameResources is no
+  // longer referenced.
+  // This could be called by any thread.
+  void MailboxHoldersReleased(FrameResources* frame_resources,
+                              uint32 sync_point);
+
+  // Return frame resources to the pool. This has to be called on the thread
+  // where |task_runner| is current.
+  void ReturnFrameResources(FrameResources* frame_resources);
+
+  // Delete resources. This has to be called on the thread where |task_runner|
+  // is current.
+  static void DeleteFrameResources(
+      const scoped_refptr<GpuVideoAcceleratorFactories>& gpu_factories,
+      FrameResources* frame_resources);
+
+  scoped_refptr<base::SingleThreadTaskRunner> task_runner_;
+  scoped_refptr<GpuVideoAcceleratorFactories> gpu_factories_;
+
+  // Pool of resources.
+  std::list<FrameResources*> resources_pool_;
+
+  unsigned texture_target_ = GL_TEXTURE_2D;
+  DISALLOW_COPY_AND_ASSIGN(PoolImpl);
+};
+
+namespace {
+
+// Copy a buffer info a GpuMemoryBuffer.
+// |bytes_per_row| is expected to be less or equal than the strides of the two
+// buffers.
+void CopyPlaneToGpuMemoryBuffer(int rows,
+                                int bytes_per_row,
+                                const uint8* source,
+                                int source_stride,
+                                gfx::GpuMemoryBuffer* buffer) {
+  TRACE_EVENT2("media", "CopyPlaneToGpuMemoryBuffer", "bytes_per_row",
+               bytes_per_row, "rows", rows);
+
+  DCHECK(buffer);
+  DCHECK(source);
+  void* data = nullptr;
+  CHECK(buffer->Map(&data));
+  uint8* mapped_buffer = static_cast<uint8*>(data);
+  int dest_stride = 0;
+  buffer->GetStride(&dest_stride);
+  DCHECK_NE(dest_stride, 0);
+  DCHECK_LE(bytes_per_row, std::abs(dest_stride));
+  DCHECK_LE(bytes_per_row, source_stride);
+  for (int row = 0; row < rows; ++row) {
+    memcpy(mapped_buffer + dest_stride * row, source + source_stride * row,
+           bytes_per_row);
+  }
+  buffer->Unmap();
+}
+
+}  // unnamed namespace
+
+// Creates a VideoFrame backed by native textures starting from a software
+// VideoFrame.
+// The data contained in video_frame is copied into the returned VideoFrame.
+scoped_refptr<VideoFrame>
+GpuMemoryBufferVideoFramePool::PoolImpl::CreateHardwareFrame(
+    const scoped_refptr<VideoFrame>& video_frame) {
+  if (!gpu_factories_)
+    return video_frame;
+
+  if (!gpu_factories_->IsTextureRGSupported())
+    return video_frame;
+
+  gpu::gles2::GLES2Interface* gles2 = gpu_factories_->GetGLES2Interface();
+  if (!gles2)
+    return video_frame;
+
+  VideoFrame::Format format = video_frame->format();
+  size_t planes = VideoFrame::NumPlanes(format);
+  DCHECK(video_frame->visible_rect().origin().IsOrigin());
+  gfx::Size size = video_frame->visible_rect().size();
+  gpu::MailboxHolder mailbox_holders[VideoFrame::kMaxPlanes];
+
+  // Acquire resources. Incompatible ones will be dropped from the pool.
+  FrameResources* frame_resources = GetOrCreateFrameResources(size, format);
+
+  // Set up the planes copying data into it and creating the mailboxes needed
+  // to refer to the textures.
+  for (size_t i = 0; i < planes; ++i) {
+    PlaneResource& plane_resource = frame_resources->plane_resources[i];
+    CopyPlaneToGpuMemoryBuffer(VideoFrame::Rows(i, format, size.height()),
+                               VideoFrame::RowBytes(i, format, size.width()),
+                               video_frame->data(i), video_frame->stride(i),
+                               plane_resource.gpu_memory_buffer.get());
+
+    // Bind the texture and create or rebind the image.
+    gles2->BindTexture(texture_target_, plane_resource.texture_id);
+
+    if (plane_resource.gpu_memory_buffer && !plane_resource.image_id) {
+      const size_t width = VideoFrame::Columns(i, format, size.width());
+      const size_t height = VideoFrame::Rows(i, format, size.height());
+      plane_resource.image_id = gles2->CreateImageCHROMIUM(
+          plane_resource.gpu_memory_buffer->AsClientBuffer(), width, height,
+          GL_R8_EXT);
+    } else {
+      gles2->ReleaseTexImage2DCHROMIUM(texture_target_,
+                                       plane_resource.image_id);
+    }
+    gles2->BindTexImage2DCHROMIUM(texture_target_, plane_resource.image_id);
+    mailbox_holders[i] =
+        gpu::MailboxHolder(plane_resource.mailbox, texture_target_, 0);
+  }
+
+  // Insert a sync_point, this is needed to make sure that the textures the
+  // mailboxes refer to will be used only after all the previous commands posted
+  // in the command buffer have been processed.
+  unsigned sync_point = gles2->InsertSyncPointCHROMIUM();
+  for (size_t i = 0; i < planes; ++i) {
+    mailbox_holders[i].sync_point = sync_point;
+  }
+
+  // Create the VideoFrame backed by native textures.
+  return VideoFrame::WrapYUV420NativeTextures(
+      mailbox_holders[VideoFrame::kYPlane],
+      mailbox_holders[VideoFrame::kUPlane],
+      mailbox_holders[VideoFrame::kVPlane],
+      base::Bind(&PoolImpl::MailboxHoldersReleased, this, frame_resources),
+      size, video_frame->visible_rect(), video_frame->natural_size(),
+      video_frame->timestamp(), video_frame->allow_overlay());
+}
+
+// Destroy all the resources posting one task per FrameResources
+// to the |task_runner_|.
+GpuMemoryBufferVideoFramePool::PoolImpl::~PoolImpl() {
+  // Delete all the resources on the media thread.
+  while (!resources_pool_.empty()) {
+    FrameResources* frame_resources = resources_pool_.front();
+    resources_pool_.pop_front();
+    task_runner_->PostTask(
+        FROM_HERE, base::Bind(&PoolImpl::DeleteFrameResources, gpu_factories_,
+                              base::Owned(frame_resources)));
+  }
+}
+
+// Tries to find the resources in the pool or create them.
+// Incompatible resources will be dropped.
+GpuMemoryBufferVideoFramePool::PoolImpl::FrameResources*
+GpuMemoryBufferVideoFramePool::PoolImpl::GetOrCreateFrameResources(
+    const gfx::Size& size,
+    VideoFrame::Format format) {
+  DCHECK(task_runner_->BelongsToCurrentThread());
+
+  auto it = resources_pool_.begin();
+  while (it != resources_pool_.end()) {
+    FrameResources* frame_resources = *it;
+    if (!frame_resources->in_use) {
+      if (AreFrameResourcesCompatible(frame_resources, size, format)) {
+        frame_resources->in_use = true;
+        return frame_resources;
+      } else {
+        resources_pool_.erase(it++);
+        DeleteFrameResources(gpu_factories_, frame_resources);
+        delete frame_resources;
+      }
+    } else {
+      it++;
+    }
+  }
+
+  // Create the resources.
+  gpu::gles2::GLES2Interface* gles2 = gpu_factories_->GetGLES2Interface();
+  DCHECK(gles2);
+  gles2->ActiveTexture(GL_TEXTURE0);
+  size_t planes = VideoFrame::NumPlanes(format);
+  FrameResources* frame_resources = new FrameResources(format, size);
+  resources_pool_.push_back(frame_resources);
+  for (size_t i = 0; i < planes; ++i) {
+    PlaneResource& plane_resource = frame_resources->plane_resources[i];
+    const size_t width = VideoFrame::Columns(i, format, size.width());
+    const size_t height = VideoFrame::Rows(i, format, size.height());
+    const gfx::Size plane_size(width, height);
+    plane_resource.gpu_memory_buffer = gpu_factories_->AllocateGpuMemoryBuffer(
+        plane_size, gfx::GpuMemoryBuffer::R_8, gfx::GpuMemoryBuffer::MAP);
+
+    gles2->GenTextures(1, &plane_resource.texture_id);
+    gles2->BindTexture(texture_target_, plane_resource.texture_id);
+    gles2->TexParameteri(texture_target_, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
+    gles2->TexParameteri(texture_target_, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
+    gles2->TexParameteri(texture_target_, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
+    gles2->TexParameteri(texture_target_, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
+    gles2->GenMailboxCHROMIUM(plane_resource.mailbox.name);
+    gles2->ProduceTextureCHROMIUM(texture_target_, plane_resource.mailbox.name);
+  }
+  return frame_resources;
+}
+
+// static
+void GpuMemoryBufferVideoFramePool::PoolImpl::DeleteFrameResources(
+    const scoped_refptr<GpuVideoAcceleratorFactories>& gpu_factories,
+    FrameResources* frame_resources) {
+  // TODO(dcastagna): As soon as the context lost is dealt with in media,
+  // make sure that we won't execute this callback (use a weak pointer to
+  // the old context).
+  gpu::gles2::GLES2Interface* gles2 = gpu_factories->GetGLES2Interface();
+  if (!gles2)
+    return;
+
+  for (PlaneResource& plane_resource : frame_resources->plane_resources) {
+    if (plane_resource.image_id)
+      gles2->DestroyImageCHROMIUM(plane_resource.image_id);
+    if (plane_resource.texture_id)
+      gles2->DeleteTextures(1, &plane_resource.texture_id);
+  }
+}
+
+// Called when a VideoFrame is no longer references.
+void GpuMemoryBufferVideoFramePool::PoolImpl::MailboxHoldersReleased(
+    FrameResources* frame_resources,
+    uint32 sync_point) {
+  // Return the resource on the media thread.
+  task_runner_->PostTask(FROM_HERE, base::Bind(&PoolImpl::ReturnFrameResources,
+                                               this, frame_resources));
+}
+
+// Put back the resoruces in the pool.
+void GpuMemoryBufferVideoFramePool::PoolImpl::ReturnFrameResources(
+    FrameResources* frame_resources) {
+  DCHECK(task_runner_->BelongsToCurrentThread());
+
+  auto it = std::find(resources_pool_.begin(), resources_pool_.end(),
+                      frame_resources);
+  DCHECK(it != resources_pool_.end());
+  // We want the pool to behave in a FIFO way.
+  // This minimizes the chances of locking the buffer that might be
+  // still needed for drawing.
+  std::swap(*it, resources_pool_.back());
+  frame_resources->in_use = false;
+}
+
+GpuMemoryBufferVideoFramePool::GpuMemoryBufferVideoFramePool(
+    const scoped_refptr<base::SingleThreadTaskRunner>& task_runner,
+    const scoped_refptr<GpuVideoAcceleratorFactories>& gpu_factories)
+    : pool_impl_(new PoolImpl(task_runner, gpu_factories)) {
+}
+
+GpuMemoryBufferVideoFramePool::~GpuMemoryBufferVideoFramePool() {
+}
+
+scoped_refptr<VideoFrame>
+GpuMemoryBufferVideoFramePool::MaybeCreateHardwareFrame(
+    const scoped_refptr<VideoFrame>& video_frame) {
+  switch (video_frame->format()) {
+    // Supported cases.
+    case VideoFrame::YV12:
+    case VideoFrame::I420:
+      return pool_impl_->CreateHardwareFrame(video_frame);
+    // Unsupported cases.
+    case media::VideoFrame::YV12A:
+    case media::VideoFrame::YV16:
+    case media::VideoFrame::YV12J:
+    case media::VideoFrame::YV12HD:
+    case media::VideoFrame::YV24:
+#if defined(VIDEO_HOLE)
+    case media::VideoFrame::HOLE:
+#endif  // defined(VIDEO_HOLE)
+    case media::VideoFrame::ARGB:
+    case media::VideoFrame::NATIVE_TEXTURE:
+    case media::VideoFrame::UNKNOWN:
+    case media::VideoFrame::NV12:
+      break;
+  }
+  return video_frame;
+}
+
+}  // namespace media