media: add video capture device for ARC++ camera HAL v3

media/capture/video/chromeos/stream_buffer_manager.cc

+// Copyright 2017 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/capture/video/chromeos/stream_buffer_manager.h"
+
+#include "media/capture/video/chromeos/camera_device_context.h"
+#include "media/capture/video/chromeos/camera_metadata_utils.h"
+#include "media/capture/video/chromeos/pixel_format_utils.h"
+#include "mojo/edk/embedder/embedder.h"
+#include "mojo/edk/embedder/scoped_platform_handle.h"
+#include "third_party/libsync/include/sync/sync.h"
+
+namespace media {
+
+StreamBufferManager::StreamBufferManager(
+    arc::mojom::Camera3CallbackOpsRequest callback_ops_request,
+    std::unique_ptr<StreamCaptureInterface> capture_interface,
+    CameraDeviceContext* device_context,
+    scoped_refptr<base::SingleThreadTaskRunner> ipc_task_runner)
+    : callback_ops_(this, std::move(callback_ops_request)),
+      capture_interface_(std::move(capture_interface)),
+      device_context_(device_context),
+      ipc_task_runner_(std::move(ipc_task_runner)),
+      capturing_(false),
+      frame_number_(0),
+      partial_result_count_(1),
+      first_frame_shutter_time_(base::TimeTicks::Now()) {
+  DCHECK(ipc_task_runner_->BelongsToCurrentThread());
+  DCHECK(callback_ops_.is_bound());
+  DCHECK(device_context_);
+}
+
+void StreamBufferManager::SetUpStreamAndBuffers(
+    VideoCaptureFormat capture_format,
+    uint32_t partial_result_count,
+    arc::mojom::Camera3StreamPtr stream) {
+  DCHECK(ipc_task_runner_->BelongsToCurrentThread());
+  DCHECK(!stream_context_);
+
+  VLOG(2) << "Stream " << stream->id << " configured: usage=" << stream->usage
+          << " max_buffers=" << stream->max_buffers;
+
+  const size_t kMaximumAllowedBuffers = 15;
+  if (stream->max_buffers > kMaximumAllowedBuffers) {
+    device_context_->SetErrorState(
+        FROM_HERE, std::string("Camera HAL requested ") +
+                       std::to_string(stream->max_buffers) +
+                       std::string(" buffers which exceeds the allowed maximum "
+                                   "number of buffers"));
+    return;
+  }
+
+  partial_result_count_ = partial_result_count;
+  stream_context_.reset(new StreamContext{capture_format, std::move(stream)});
+
+  // Allocate buffers.
+  size_t num_buffers = stream_context_->stream->max_buffers;
+  stream_context_->buffers.resize(num_buffers);
+  for (size_t j = 0; j < num_buffers; ++j) {
+    const VideoCaptureFormat frame_format(
+        gfx::Size(stream_context_->stream->width,
+                  stream_context_->stream->height),
+        0.0, stream_context_->capture_format.pixel_format);
+    std::unique_ptr<base::SharedMemory> buffer(new base::SharedMemory());
+    base::SharedMemoryCreateOptions options;
+    options.size = frame_format.ImageAllocationSize();
+    options.share_read_only = false;
+    bool ret = buffer->Create(options);
+    if (!ret) {
+      device_context_->SetErrorState(FROM_HERE,
+                                     "Failed to create SharedMemory buffer");
+      return;
+    }
+    ret = buffer->Map(buffer->requested_size());
+    if (!ret) {
+      device_context_->SetErrorState(FROM_HERE,
+                                     "Failed to map SharedMemory buffer");
+      return;
+    }
+    stream_context_->buffers[j] = std::move(buffer);
+    stream_context_->free_buffers.push(j);
+  }
+  VLOG(2) << "Allocated " << stream_context_->stream->max_buffers << " buffers";
+}
+
+void StreamBufferManager::StartCapture(arc::mojom::CameraMetadataPtr settings) {
+  DCHECK(ipc_task_runner_->BelongsToCurrentThread());
+  DCHECK(stream_context_);
+  DCHECK(stream_context_->request_settings.is_null());
+
+  capturing_ = true;
+  stream_context_->request_settings = std::move(settings);
+  // We cannot use a loop to register all the free buffers in one shot here
+  // because the camera HAL v3 API specifies that the client cannot call
+  // ProcessCaptureRequest before the previous one returns.
+  RegisterBuffer();
+}
+
+void StreamBufferManager::StopCapture() {
+  DCHECK(ipc_task_runner_->BelongsToCurrentThread());
+  capturing_ = false;
+}
+
+void StreamBufferManager::RegisterBuffer() {
+  DCHECK(ipc_task_runner_->BelongsToCurrentThread());
+  DCHECK(stream_context_);
+
+  if (!capturing_) {
+    return;
+  }
+
+  if (stream_context_->free_buffers.empty()) {
+    return;
+  }
+
+  size_t buffer_id = stream_context_->free_buffers.front();
+  stream_context_->free_buffers.pop();
+  const base::SharedMemory* buffer = stream_context_->buffers[buffer_id].get();
+
+  VideoPixelFormat buffer_format = stream_context_->capture_format.pixel_format;
+  uint32_t drm_format = PixFormatChromiumToDrm(buffer_format);
+  if (!drm_format) {
+    device_context_->SetErrorState(
+        FROM_HERE, std::string("Unsupported video pixel format") +
+                       VideoPixelFormatToString(buffer_format));
+    return;
+  }
+  arc::mojom::HalPixelFormat hal_pixel_format = stream_context_->stream->format;
+
+  size_t num_planes = VideoFrame::NumPlanes(buffer_format);
+  std::vector<mojo::ScopedHandle> fds(num_planes);
+  std::vector<uint32_t> strides(num_planes);
+  std::vector<uint32_t> offsets(num_planes);
+  for (size_t i = 0; i < num_planes; ++i) {
+    base::SharedMemoryHandle shm_handle = buffer->handle();
+    // Wrap the platform handle.
+    MojoHandle wrapped_handle;
+    MojoResult result = mojo::edk::CreatePlatformHandleWrapper(
+        mojo::edk::ScopedPlatformHandle(mojo::edk::PlatformHandle(
+            base::SharedMemory::DuplicateHandle(shm_handle).GetHandle())),
+        &wrapped_handle);
+    if (result != MOJO_RESULT_OK) {
+      device_context_->SetErrorState(FROM_HERE,
+                                     "Failed to wrap shared memory handle");
+      return;
+    }
+    fds[i].reset(mojo::Handle(wrapped_handle));
+    strides[i] = VideoFrame::RowBytes(
+        i, buffer_format, stream_context_->capture_format.frame_size.width());
+    if (!i) {
+      offsets[i] = 0;
+    } else {
+      offsets[i] =
+          offsets[i - 1] +
+          VideoFrame::PlaneSize(buffer_format, i - 1,
+                                stream_context_->capture_format.frame_size)
+              .GetArea();
+    }
+  }
+  capture_interface_->RegisterBuffer(
+      buffer_id, arc::mojom::Camera3DeviceOps::BufferType::SHM, std::move(fds),
+      drm_format, hal_pixel_format, stream_context_->stream->width,
+      stream_context_->stream->height, std::move(strides), std::move(offsets),
+      base::Bind(&StreamBufferManager::OnRegisteredBuffer, this, buffer_id));
+  VLOG(2) << "Registered buffer " << buffer_id;
+}
+
+void StreamBufferManager::OnRegisteredBuffer(size_t buffer_id, int32_t result) {
+  DCHECK(ipc_task_runner_->BelongsToCurrentThread());
+
+  if (!capturing_) {
+    return;
+  }
+  if (result) {
+    device_context_->SetErrorState(FROM_HERE,
+                                   std::string("Failed to register buffer: ") +
+                                       std::string(strerror(result)));
+    return;
+  }
+  ProcessCaptureRequest(buffer_id);
+}
+
+void StreamBufferManager::ProcessCaptureRequest(size_t buffer_id) {
+  DCHECK(ipc_task_runner_->BelongsToCurrentThread());
+  DCHECK(stream_context_);
+
+  arc::mojom::Camera3StreamBufferPtr buffer =
+      arc::mojom::Camera3StreamBuffer::New();
+  buffer->stream_id = static_cast<uint64_t>(
+      arc::mojom::Camera3RequestTemplate::CAMERA3_TEMPLATE_PREVIEW);
+  buffer->buffer_id = buffer_id;
+  buffer->status = arc::mojom::Camera3BufferStatus::CAMERA3_BUFFER_STATUS_OK;
+
+  arc::mojom::Camera3CaptureRequestPtr request =
+      arc::mojom::Camera3CaptureRequest::New();
+  request->frame_number = frame_number_;
+  request->settings = stream_context_->request_settings.Clone();
+  request->output_buffers.push_back(std::move(buffer));
+
+  capture_interface_->ProcessCaptureRequest(
+      std::move(request),
+      base::Bind(&StreamBufferManager::OnProcessedCaptureRequest, this));
+  VLOG(2) << "Requested capture for frame " << frame_number_ << " with buffer "
+          << buffer_id;
+  frame_number_++;
+  // In case |frame_number_| wraps around, we start at 1 to avoid resetting
+  // |first_frame_shutter_time_|.
+  if (!frame_number_) {
+    frame_number_++;
+  }
+}
+
+void StreamBufferManager::OnProcessedCaptureRequest(int32_t result) {
+  DCHECK(ipc_task_runner_->BelongsToCurrentThread());
+
+  if (!capturing_) {
+    return;
+  }
+  if (result) {
+    device_context_->SetErrorState(
+        FROM_HERE, std::string("Process capture request failed") +
+                       std::string(strerror(result)));
+    return;
+  }
+  RegisterBuffer();
+}
+
+void StreamBufferManager::ProcessCaptureResult(
+    arc::mojom::Camera3CaptureResultPtr result) {
+  DCHECK(ipc_task_runner_->BelongsToCurrentThread());
+
+  if (!capturing_) {
+    return;
+  }
+  uint32_t frame_number = result->frame_number;
+  // A new partial result may be created in either ProcessCaptureResult or
+  // Notify.
+  CaptureResult& partial_result = partial_results_[frame_number];
+  if (partial_results_.size() > stream_context_->stream->max_buffers) {
+    device_context_->SetErrorState(
+        FROM_HERE,
+        "Received more capture results than the maximum number of buffers");
+    return;
+  }
+  if (result->output_buffers) {
+    if (result->output_buffers->size() != 1) {
+      device_context_->SetErrorState(
+          FROM_HERE,
+          std::string("Incorrect number of output buffers received: ") +
+              std::to_string(result->output_buffers->size()));
+      return;
+    }
+    arc::mojom::Camera3StreamBufferPtr& stream_buffer =
+        result->output_buffers.value()[0];
+    VLOG(2) << "Received capture result for frame " << frame_number
+            << " stream_id: " << stream_buffer->stream_id;
+    // The camera HAL v3 API specifies that only one capture result can carry
+    // the result buffer for any given frame number.
+    if (!partial_result.buffer.is_null()) {
+      device_context_->SetErrorState(
+          FROM_HERE,
+          std::string("Received multiple result buffers for frame ") +
+              std::to_string(frame_number));
+      return;
+    } else {
+      partial_result.buffer = std::move(stream_buffer);
+      // If the buffer is marked as error it is due to either a request or a
+      // buffer error.  In either case the content of the buffer must be dropped
+      // and the buffer can be reused.  We simply submit the buffer here and
+      // don't wait for any partial results.  SubmitCaptureResult() will drop
+      // and resuse the buffer.
+      if (partial_result.buffer->status ==
+          arc::mojom::Camera3BufferStatus::CAMERA3_BUFFER_STATUS_ERROR) {
+        SubmitCaptureResult(frame_number);
+        return;
+      }
+    }
+  }
+
+  // |result->partial_result| is set to 0 if the capture result contains only
+  // the result buffer handles and no result metadata.
+  if (result->partial_result) {
+    uint32_t result_id = result->partial_result;
+    if (result_id > partial_result_count_) {
+      device_context_->SetErrorState(
+          FROM_HERE, std::string("Invalid partial_result id: ") +
+                         std::to_string(result_id));
+      return;
+    }
+    if (partial_result.partial_metadata_received.find(result_id) !=
+        partial_result.partial_metadata_received.end()) {
+      device_context_->SetErrorState(
+          FROM_HERE, std::string("Received duplicated partial metadata: ") +
+                         std::to_string(result_id));
+      return;
+    }
+    partial_result.partial_metadata_received.insert(result_id);
+    MergeMetadata(&partial_result.metadata, result->result);
+  }
+
+  if (partial_result.partial_metadata_received.size() ==
+          partial_result_count_ &&
+      !partial_result.buffer.is_null()) {
+    // We can only submit the result buffer after we receive the shutter time.
+    if (partial_result.reference_time != base::TimeTicks()) {
+      SubmitCaptureResult(frame_number);
+    }
+  }
+}
+
+void StreamBufferManager::Notify(arc::mojom::Camera3NotifyMsgPtr message) {
+  DCHECK(ipc_task_runner_->BelongsToCurrentThread());
+
+  if (!capturing_) {
+    return;
+  }
+  if (message->type == arc::mojom::Camera3MsgType::CAMERA3_MSG_ERROR) {
+    uint32_t frame_number = message->message->get_error()->frame_number;
+    uint64_t error_stream_id = message->message->get_error()->error_stream_id;
+    arc::mojom::Camera3ErrorMsgCode error_code =
+        message->message->get_error()->error_code;
+    HandleNotifyError(frame_number, error_stream_id, error_code);
+  } else {  // arc::mojom::Camera3MsgType::CAMERA3_MSG_SHUTTER
+    uint32_t frame_number = message->message->get_shutter()->frame_number;
+    uint64_t shutter_time = message->message->get_shutter()->timestamp;
+    // A new partial result may be created in either ProcessCaptureResult or
+    // Notify.
+    VLOG(2) << "Received shutter time for frame " << frame_number;
+    if (!shutter_time) {
+      device_context_->SetErrorState(
+          FROM_HERE, std::string("Received invalid shutter time: ") +
+                         std::to_string(shutter_time));
+      return;
+    }
+    CaptureResult& partial_result = partial_results_[frame_number];

[chfremer, 2017/06/08 21:58:38]

Idea for a possible improvement: If we wanted to further break down the
complexity into smaller and easier digestable/testable/maintainable pieces, one
potential strategy to do so might be to move the logic for accumulating these
partial results, verifying their correctness and correct order into a separate
class, e.g. something that could be called PartialResultsAccumulator. This would
leave the class StreamBufferManager with the core flow of the capture loop as
its single responsibility, and with the methods becoming shorter and free of
other responsibilities, this flow would become nicely obvious. We could then
even think about renaming the class to something like CaptureMainLoop.

[jcliang, 2017/06/09 05:16:01]

This sounds like a good design improvement. I'll see if I can split the
responsibilities in another CL. I think it may help the befriending test class
issue you mentioned.

+    if (partial_results_.size() > stream_context_->stream->max_buffers) {
+      device_context_->SetErrorState(
+          FROM_HERE,
+          "Received more capture results than the maximum number of buffers");
+      return;
+    }
+    // Shutter timestamp is in ns.
+    base::TimeTicks reference_time =
+        base::TimeTicks::FromInternalValue(shutter_time / 1000);
+    partial_result.reference_time = reference_time;
+    if (!frame_number) {
+      // Record the shutter time of the first frame for calculating the
+      // timestamp.
+      first_frame_shutter_time_ = reference_time;
+    }
+    partial_result.timestamp = reference_time - first_frame_shutter_time_;
+    if (partial_result.partial_metadata_received.size() ==
+            partial_result_count_ &&
+        !partial_result.buffer.is_null()) {
+      SubmitCaptureResult(frame_number);
+    }
+  }
+}
+
+void StreamBufferManager::HandleNotifyError(
+    uint32_t frame_number,
+    uint64_t error_stream_id,
+    arc::mojom::Camera3ErrorMsgCode error_code) {
+  switch (error_code) {
+    case arc::mojom::Camera3ErrorMsgCode::CAMERA3_MSG_ERROR_DEVICE:
+      // Fatal error and no more frames will be produced by the device.
+      device_context_->SetErrorState(FROM_HERE, "Fatal device error");
+      break;
+    case arc::mojom::Camera3ErrorMsgCode::CAMERA3_MSG_ERROR_REQUEST: {
+      // An error has occurred in processing the request; the request
+      // specified by |frame_number| has been dropped by the camera device.
+      // Subsequent requests are unaffected.
+      //
+      // The HAL will call ProcessCaptureResult with the buffers' state set to
+      // STATUS_ERROR.  The content of the buffers will be dropped and the
+      // buffers will be reused in SubmitCaptureResult.
+      std::string warning_msg =
+          std::string("An error occurred while processing request for frame ") +
+          std::to_string(frame_number);
+      LOG(WARNING) << warning_msg;
+      device_context_->LogToClient(warning_msg);
+      break;
+    }
+    case arc::mojom::Camera3ErrorMsgCode::CAMERA3_MSG_ERROR_RESULT: {
+      // An error has occurred in producing the output metadata buffer for a
+      // result; the output metadata will not be available for the frame
+      // specified by |frame_number|.  Subsequent requests are unaffected.
+      std::string warning_msg = std::string(
+                                    "An error occurred while producing result "
+                                    "metadata for frame ") +
+                                std::to_string(frame_number);
+      LOG(WARNING) << warning_msg;
+      device_context_->LogToClient(warning_msg);
+      CaptureResult& partial_result = partial_results_[frame_number];
+      // The result metadata will not be complete so we don't need to wait for
+      // partial results on frame |frame_number|.
+      partial_result.partial_metadata_received.clear();
+      for (uint32_t i = 0; i < partial_result_count_; ++i) {
+        partial_result.partial_metadata_received.insert(i);
+      }
+      // If the buffer is already returned by the HAL, submit it and we're done.
+      if (!partial_result.buffer.is_null()) {
+        SubmitCaptureResult(frame_number);
+      }
+      break;
+    }
+    case arc::mojom::Camera3ErrorMsgCode::CAMERA3_MSG_ERROR_BUFFER:
+      // An error has occurred in placing the output buffer into a stream for
+      // a request. |frame_number| specifies the request for which the buffer
+      // was dropped, and |error_stream_id| specifies the stream that dropped
+      // the buffer.
+      //
+      // The HAL will call ProcessCaptureResult with the buffer's state set to
+      // STATUS_ERROR.  The content of the buffer will be dropped and the
+      // buffer will be reused in SubmitCaptureResult.
+      device_context_->LogToClient(
+          std::string(
+              "An error occurred while filling output buffer of stream ") +
+          std::to_string(error_stream_id) + std::string(" in frame ") +
+          std::to_string(frame_number));
+      break;
+    default:
+      // To eliminate the warning for not handling CAMERA3_MSG_NUM_ERRORS
+      break;
+  }
+}
+
+void StreamBufferManager::SubmitCaptureResult(uint32_t frame_number) {
+  DCHECK(ipc_task_runner_->BelongsToCurrentThread());
+
+  if (partial_results_.begin()->first != frame_number) {
+    device_context_->SetErrorState(
+        FROM_HERE, std::string("Received frame is out-of-order; expect ") +
+                       std::to_string(partial_results_.begin()->first) +
+                       std::string(" but got ") + std::to_string(frame_number));
+    return;
+  }
+
+  VLOG(2) << "Submit capture result of frame " << frame_number;
+  CaptureResult& partial_result = partial_results_[frame_number];
+  DCHECK(partial_result.buffer);
+  uint32_t buffer_id = partial_result.buffer->buffer_id;
+
+  // Wait on release fence before delivering the result buffer to client.
+  if (partial_result.buffer->release_fence.is_valid()) {
+    const int kSyncWaitTimeoutMs = 1000;
+    mojo::edk::ScopedPlatformHandle fence;
+    MojoResult result = mojo::edk::PassWrappedPlatformHandle(
+        partial_result.buffer->release_fence.release().value(), &fence);
+    if (result != MOJO_RESULT_OK) {
+      device_context_->SetErrorState(FROM_HERE,
+                                     "Failed to unwrap release fence fd");
+      return;
+    }
+    if (!sync_wait(fence.get().handle, kSyncWaitTimeoutMs)) {

[chfremer, 2017/06/08 21:58:38]

So, if I understand this correctly, for each frame, we are sharing a buffer with
the HAL service. The service maps the buffer to its memory space, places data
into the buffer and then unmaps the buffer again. Here we wait for the unmapping
to complete.

What is the resource cost / performance overhead of the repeated
sharing/mapping/unmapping? 
The buffer sharing between video capture service, Browser, and Renderers works
differently, and does so explicitly to avoid the cost of repeated mapping and
unmapping. What is done there is to keep buffers shared (up to a given maximum
number of them). When the frame data producer has placed data into a buffer, it
does not unmap, but simply sends a message that says that data is available.
When the consumer has finished consuming the data, it sends a message to the
producer to let it know that the buffer is ready to be reused.

Ideally, we would have a single reusable implementation for transporting frame
data across process boundaries and would be applying it wherever needed (not
just for video data). It seem we are currently going the way of having separate
implementations for each case, non of which is reusable. Fixing this would
probably be quite a bit of work, and I don't want this to block the progress on
the ARC++ HALv3 work, but I think this should eventually be our goal.

[jcliang, 2017/06/09 05:16:01]

Yes your understanding regarding the buffer circulation and operation is
correct. The map/unmap operations are unavoidable currently due to several
reasons:

1. The Android HALv3 API explicitly specifies that the camera HAL must expect
that the buffer handle it receives in each capture request to be a new buffer
which it has never seen before.

2. The user space processes need to map/unmap buffers because I'm using
SharedMemory in this implementation.

1. is the fundamental limitation that stops us to use a fixed set of shared
SharedMemory buffers.

In the optimized scenario the user space processes do not need to map/unmap the
buffers. The buffers can be passed to the hardware for processing during the
pipeline (e.g. give the buffer fd to the camera driver or image signal processor
driver directly and let the driver map the buffer in IOMMU). To achieve this
would require several changes (on Chrome OS and Linux, I don't know about
Windows and Mac :/):

a. Use dmabuf not shared-memory, so that the buffers can be imported and used by
kernel drivers easily. In general shared-memory is not very friendly to driver
use cases. We've run into various tricky alignment issues with Chrome's
shared-memory on Chrome OS.

b. Refactor Chrome to use dmabuf and only pass the buffer FD whenever possible.

a. is in my TODO list. I'm going to change the SharedMemory to dmabuf on the
ARC++ HALv3 VCD (i.e. change the buffer allocation in the
SetUpStreamAndBuffers() above).

b. on the other hand would require some code refactors that affect all
platforms. For example, in the current OnIncomingCapturedData implementation it
has to do a memcpy even if the received buffer is of format I420.

In the world on modern Linux kernel the "single reusable" implementation is to
use dmabuf everywhere whenever possible, but as Chrome also needs to run on
Windows and Mac I'm not sure how we can design this buffer circulation mechanism
(I know too little about how Chrome works on other platforms).

[chfremer, 2017/06/09 17:53:17]

I have to say that I don't fully understand the context, so apologies if my
questions may seem a bit silly here.

I was assuming that this code here running in Chromium is talking to a Chrome OS
service (running with system privileges, but not being a kernel module) which we
designed and implemented as well, and which is also used by Android-on-ChromeOS.
If this system service currently wants to treat each buffer handle as new and
map/unmap it for each frame I understand that the Chromium code here needs to
match that. However, if we control the design and implementation of the system
service, why couldn't we change it to allow reusing shared buffers if that would
help us?

Is it not possible/allowed to have shared memory mapped simultaneously by both a
user-space process and a system service?

[jcliang, 2017/06/12 08:52:39]

The camera service on Chrome OS has two parts:

1. A camera HAL adapter which loads a device-specific camera HAL library, and
talk to Chrome and Android container to provide them with camera functions. This
part is designed and implemented by Google.
2. A device-specific camera HAL library which include codes that are tailored
for specific hardware. This part is provided by our partners.

The interface we use between 1. and 2. is the Android camera HAL v3 APIs, which
specifies the constraints on the buffers. We can change or relax the
constraints, but that would break the original API contract and our partners
will need to modify their HAL library accordingly.

AFAIK, we do relax this constraint on some Android devices to improve the
performance. In general it's easier for Android to do per-device optimizations.
In Chrome OS we have to maintain dozens of different devices at the same time
and doing board-specific code changes in general camera code path is not
trivial.
Mapping the same shared memory into different processes is not a problem, but
we'd like to follow the Android API specification for now.

+      device_context_->SetErrorState(FROM_HERE,
+                                     "Sync wait on release fence timed out");
+      return;
+    }
+  }
+
+  // Deliver the captured data to client and then re-queue the buffer.
+  if (partial_result.buffer->status !=
+      arc::mojom::Camera3BufferStatus::CAMERA3_BUFFER_STATUS_ERROR) {
+    DCHECK_EQ(partial_result.partial_metadata_received.size(),
+              partial_result_count_);
+    const base::SharedMemory* shm_buffer =
+        stream_context_->buffers[buffer_id].get();
+    device_context_->SubmitCapturedData(
+        reinterpret_cast<uint8_t*>(shm_buffer->memory()),
+        shm_buffer->mapped_size(), stream_context_->capture_format,
+        partial_result.reference_time, partial_result.timestamp);
+  }
+  stream_context_->free_buffers.push(buffer_id);
+  partial_results_.erase(frame_number);
+  RegisterBuffer();
+}
+
+}  // namespace media