Add media::VideoEncodeAccelerator with WebRTC integration

content/common/gpu/media/gpu_video_encode_accelerator.cc

+// Copyright (c) 2013 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 "content/common/gpu/media/gpu_video_encode_accelerator.h"
+
+#include "base/logging.h"
+#include "base/memory/shared_memory.h"
+#include "content/common/gpu/gpu_channel.h"
+#include "content/common/gpu/gpu_messages.h"
+#include "ipc/ipc_message_macros.h"
+#include "media/base/video_frame.h"
+
+namespace content {
+
+GpuVideoEncodeAccelerator::GpuVideoEncodeAccelerator(GpuChannel* gpu_channel,
+                                                     int32 route_id)
+    : channel_(gpu_channel),
+      route_id_(route_id),
+      input_format_(media::VideoFrame::INVALID),
+      output_buffer_size_(0) {}
+
+GpuVideoEncodeAccelerator::~GpuVideoEncodeAccelerator() {
+  if (encoder_)
+    encoder_.release()->Destroy();
+}
+
+bool GpuVideoEncodeAccelerator::OnMessageReceived(const IPC::Message& message) {
+  bool handled = true;
+  IPC_BEGIN_MESSAGE_MAP(GpuVideoEncodeAccelerator, message)
+    IPC_MESSAGE_HANDLER(AcceleratedVideoEncoderMsg_Initialize, OnInitialize)
+    IPC_MESSAGE_HANDLER(AcceleratedVideoEncoderMsg_Encode, OnEncode)
+    IPC_MESSAGE_HANDLER(AcceleratedVideoEncoderMsg_UseOutputBitstreamBuffer,
+                        OnUseOutputBitstreamBuffer)
+    IPC_MESSAGE_HANDLER(
+        AcceleratedVideoEncoderMsg_RequestEncodingParametersChange,
+        OnRequestEncodingParametersChange)
+    IPC_MESSAGE_UNHANDLED(handled = false)
+  IPC_END_MESSAGE_MAP()
+  return handled;
+}
+
+void GpuVideoEncodeAccelerator::OnChannelError() {
+  NotifyError(media::VideoEncodeAccelerator::kPlatformFailureError);
+  if (channel_)
+    channel_ = NULL;
+}
+
+void GpuVideoEncodeAccelerator::NotifyInitializeDone() {
+  Send(new AcceleratedVideoEncoderHostMsg_NotifyInitializeDone(route_id_));
+}
+
+void GpuVideoEncodeAccelerator::RequireBitstreamBuffers(
+    int input_count,
+    const gfx::Size& input_coded_size,
+    size_t output_buffer_size) {
+  Send(new AcceleratedVideoEncoderHostMsg_RequireBitstreamBuffers(
+      route_id_, input_count, input_coded_size, output_buffer_size));
+  input_coded_size_ = input_coded_size;
+  output_buffer_size_ = output_buffer_size;
+}
+
+void GpuVideoEncodeAccelerator::BitstreamBufferReady(int32 bitstream_buffer_id,
+                                                     size_t payload_size,
+                                                     bool key_frame) {
+  Send(new AcceleratedVideoEncoderHostMsg_BitstreamBufferReady(
+      route_id_, bitstream_buffer_id, payload_size, key_frame));
+}
+
+void GpuVideoEncodeAccelerator::NotifyError(
+    media::VideoEncodeAccelerator::Error error) {
+  Send(new AcceleratedVideoEncoderHostMsg_NotifyError(route_id_, error));
+}
+
+// static
+std::vector<media::VideoEncodeAccelerator::SupportedProfile>
+GpuVideoEncodeAccelerator::GetSupportedProfiles() {
+  std::vector<media::VideoEncodeAccelerator::SupportedProfile> profiles;
+
+  // TODO(sheu): return platform-specific profiles.
+  return profiles;
+}
+
+void GpuVideoEncodeAccelerator::CreateEncoder() {
+  // TODO(sheu): actual create the encoder.
+}
+
+void GpuVideoEncodeAccelerator::OnInitialize(
+    media::VideoFrame::Format input_format,
+    const gfx::Size& input_visible_size,
+    media::VideoCodecProfile output_profile,
+    int32 initial_bitrate) {
+  DVLOG(2) << "GpuVideoEncodeAccelerator::OnInitialize(): "
+              "input_format=" << input_format
+           << ", input_visible_size=" << input_visible_size.ToString()
+           << ", output_profile=" << output_profile
+           << ", initial_bitrate=" << initial_bitrate;
+  DCHECK(!encoder_);
+
+  CreateEncoder();
+  if (!encoder_) {
+    DLOG(ERROR) << "GpuVideoEncodeAccelerator::OnInitialize(): VEA creation "
+                   "failed";
+    NotifyError(media::VideoEncodeAccelerator::kPlatformFailureError);
+    return;
+  }
+  encoder_->Initialize(
+      input_format, input_visible_size, output_profile, initial_bitrate);
+  input_format_ = input_format;
+  input_visible_size_ = input_visible_size;
+}
+
+void GpuVideoEncodeAccelerator::OnEncode(int32 frame_id,
+                                         base::SharedMemoryHandle buffer_handle,
+                                         uint32 buffer_size,
+                                         bool force_keyframe) {
+  DVLOG(3) << "GpuVideoEncodeAccelerator::OnEncode(): frame_id=" << frame_id
+           << ", buffer_size=" << buffer_size
+           << ", force_keyframe=" << force_keyframe;
+  if (!encoder_)
+    return;
+  if (frame_id < 0) {
+    DLOG(ERROR) << "GpuVideoEncodeAccelerator::OnEncode(): invalid frame_id="
+                << frame_id;
+    NotifyError(media::VideoEncodeAccelerator::kPlatformFailureError);
+    return;
+  }
+
+  scoped_ptr<base::SharedMemory> shm(
+      new base::SharedMemory(buffer_handle, true));
+  if (!shm->Map(buffer_size)) {
+    DLOG(ERROR) << "GpuVideoEncodeAccelerator::OnEncode(): "
+                   "could not map frame_id=" << frame_id;
+    NotifyError(media::VideoEncodeAccelerator::kPlatformFailureError);
+    return;
+  }
+
+  scoped_refptr<media::VideoFrame> frame;
+  switch (input_format_) {
+    case media::VideoFrame::I420: {
+      if (buffer_size <
+          static_cast<size_t>(input_coded_size_.GetArea() * 3 / 2)) {
+        DLOG(ERROR) << "GpuVideoEncodeAccelerator::OnEncode(): "
+                       "buffer too small for frame_id=" << frame_id;
+        NotifyError(media::VideoEncodeAccelerator::kPlatformFailureError);
+        return;
+      }
+      uint8* data = reinterpret_cast<uint8*>(shm->memory());
+      frame = media::VideoFrame::WrapExternalYuvData(
+          media::VideoFrame::I420,
+          input_coded_size_,
+          gfx::Rect(input_visible_size_),
+          input_visible_size_,
+          input_coded_size_.width(),
+          input_coded_size_.width() / 2,
+          input_coded_size_.width() / 2,
+          data,
+          data + input_coded_size_.GetArea(),
+          data + (input_coded_size_.GetArea() * 5 / 4),
+          base::TimeDelta(),
+          buffer_handle,
+          base::Bind(&GpuVideoEncodeAccelerator::EncodeFrameFinished,
+                     base::Unretained(this),

[piman, 2013/08/09 04:04:58]

what makes this Unretained safe?

[sheu, 2013/08/09 08:26:41]

That's an interesting question, I guess.  I was assuming that this would wrap
the lifetime of the underlying VEA, which would would be the only owners of the
VideoFrame.

But I guess I can't assume that the VEA won't pass this off elsewhere, or even
that we can bound the lifetime of the VEA (since it's only Destroy()ed, not
explicitly destructed.)

So, moving to weak_ptr.  You're gonna _love_ this tower of base::Bind()-ing.

[piman, 2013/08/12 21:43:40]

Why do you then need the extra PostTask?

[sheu, 2013/08/12 21:58:18]

The VideoFrame destructor will call the callback, but the destructor might
itself be called on any thread since we're holding references to the VideoFrame
through a thread-safe scoped_refptr.  We want to make sure the call to
EncodeFrameFinished happens on this thread.

Thus the tower of power.

[piman, 2013/08/13 01:00:04]

Ok.

+                     frame_id,
+                     base::Passed(&shm)));
+      break;
+    }
+    default:
+      NOTREACHED();

[piman, 2013/08/09 04:04:58]

This comes from the untrusted renderer, so it can be reached. Maybe DVLOG
instead?

[sheu, 2013/08/09 08:26:41]

Right, if it's reached, we proceed to return an error below.  Do we want to not
NOTREACHED() this?

[piman, 2013/08/12 21:43:40]

It can give a false sense of security, which, for security-critical code (IPC
handler) is rather unfortunate. Hence DVLOG?

[sheu, 2013/08/12 21:58:18]

Sure -- in any case though this has been pulled into
media::VideoFrame::WrapSharedMemoryBuffer(), so it's moot now.

+      NotifyError(media::VideoEncodeAccelerator::kPlatformFailureError);
+      return;
+  }
+
+  encoder_->Encode(frame, force_keyframe);
+}
+
+void GpuVideoEncodeAccelerator::OnUseOutputBitstreamBuffer(
+    int32 buffer_id,
+    base::SharedMemoryHandle buffer_handle,
+    uint32 buffer_size) {
+  DVLOG(3) << "GpuVideoEncodeAccelerator::OnUseOutputBitstreamBuffer(): "
+              "buffer_id=" << buffer_id
+           << ", buffer_size=" << buffer_size;
+  if (!encoder_)
+    return;
+  if (buffer_id < 0) {
+    DLOG(ERROR) << "GpuVideoEncodeAccelerator::OnUseOutputBitstreamBuffer(): "
+                   "invalid buffer_id=" << buffer_id;
+    NotifyError(media::VideoEncodeAccelerator::kPlatformFailureError);
+    return;
+  }
+  if (buffer_size < output_buffer_size_) {
+    DLOG(ERROR) << "GpuVideoEncodeAccelerator::OnUseOutputBitstreamBuffer(): "
+                   "buffer too small for buffer_id=" << buffer_id;
+    NotifyError(media::VideoEncodeAccelerator::kPlatformFailureError);
+    return;
+  }
+  encoder_->UseOutputBitstreamBuffer(
+      media::BitstreamBuffer(buffer_id, buffer_handle, buffer_size));

[piman, 2013/08/09 04:04:58]

what happens if buffer_handle is invalid, or doesn't match buffer_size?
Is every encoder required to implement the security around it?
Can we do it here instead?

[sheu, 2013/08/09 08:26:41]

If the buffer handle is invalid, mapping it will fail.  There's no way to know
its buffer size though other than what we're passed through IPC, so there really
isn't a way around this.  We're relying on the security of the underlying
mmap().

media::BitstreamBuffer is spec-ed in terms of handles, so handles we do.  It
serves for the decoder.

[piman, 2013/08/12 21:43:40]

We want to make sure this is properly communicated, and handled by all the
encoders. E.g. we don't want the encoder to make security decisions based on the
size until it knows that the size is correct.

Really ideally the checking code would be here.

[sheu, 2013/08/12 21:58:18]

Right, but how do we know the buffer size?  It's going to have to come down IPC
somehow.

[piman, 2013/08/13 01:00:04]

You have no way of knowing it (well, fstat would on posix), but you could verify
that mapping it with that size succeeds.

[sheu, 2013/08/13 01:07:08]

Right, and the solution adopted elsewhere (i.e. the video decoders) is to check
for failure on mapping when the mapping occurs, in the individual encoder.

It would be good to do it at a higher level, but we since we just pass a handle
down to the encoder, another mapping here would be redundant.

+}
+
+void GpuVideoEncodeAccelerator::OnRequestEncodingParametersChange(
+    int32 bitrate,
+    uint32 framerate) {
+  DVLOG(2) << "GpuVideoEncodeAccelerator::OnRequestEncodingParametersChange(): "
+              "bitrate=" << bitrate
+           << ", framerate=" << framerate;
+  if (!encoder_)
+    return;
+  encoder_->RequestEncodingParametersChange(bitrate, framerate);
+}
+
+void GpuVideoEncodeAccelerator::EncodeFrameFinished(
+    int32 frame_id,
+    scoped_ptr<base::SharedMemory> shm) {
+  Send(new AcceleratedVideoEncoderHostMsg_NotifyInputDone(route_id_, frame_id));
+  // Just let shm fall out of scope.
+}
+
+void GpuVideoEncodeAccelerator::Send(IPC::Message* message) {
+  if (!channel_) {
+    DLOG(ERROR) << "GpuVideoEncodeAccelerator::Send(): no channel";
+    delete message;
+    return;
+  } else if (!channel_->Send(message)) {
+    DLOG(ERROR) << "GpuVideoEncodeAccelerator::Send(): sending failed: "
+                   "message->type()=" << message->type();
+    NotifyError(media::VideoEncodeAccelerator::kPlatformFailureError);
+    return;
+  }
+}
+
+}  // namespace content