Video capture implementation using the Media Foundation API.

media/video/capture/win/video_capture_device_mf_win.cc

+// 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.
+
+#include "media/video/capture/win/video_capture_device_mf_win.h"
+
+#include <mfapi.h>
+#include <mferror.h>
+
+#include "base/lazy_instance.h"
+#include "base/memory/ref_counted.h"
+#include "base/synchronization/waitable_event.h"
+#include "base/sys_string_conversions.h"
+#include "base/win/scoped_co_mem.h"
+#include "media/video/capture/win/capability_list_win.h"
+
+using base::win::ScopedCoMem;
+using base::win::ScopedComPtr;
+
+namespace media {
+namespace {
+
+class MFInitializerSingleton {
+ public:
+  MFInitializerSingleton() { MFStartup(MF_VERSION, MFSTARTUP_LITE); }
+  ~MFInitializerSingleton() { MFShutdown(); }
+};
+
+static base::LazyInstance<MFInitializerSingleton> g_mf_initialize =
+    LAZY_INSTANCE_INITIALIZER;
+
+void EnsureMFInit() {
+  g_mf_initialize.Get();
+}
+
+bool PrepareVideoCaptureAttributes(IMFAttributes** attributes, int count) {
+  EnsureMFInit();
+
+  if (FAILED(MFCreateAttributes(attributes, count)))
+    return false;
+
+  return SUCCEEDED((*attributes)->SetGUID(MF_DEVSOURCE_ATTRIBUTE_SOURCE_TYPE,
+      MF_DEVSOURCE_ATTRIBUTE_SOURCE_TYPE_VIDCAP_GUID));
+}
+
+bool EnumerateVideoDevices(IMFActivate*** devices,
+                           UINT32* count) {
+  ScopedComPtr<IMFAttributes> attributes;
+  if (!PrepareVideoCaptureAttributes(attributes.Receive(), 1))
+    return false;
+
+  return SUCCEEDED(MFEnumDeviceSources(attributes, devices, count));
+}
+
+bool CreateVideoCaptureDevice(const char* sym_link, IMFMediaSource** source) {
+  ScopedComPtr<IMFAttributes> attributes;
+  if (!PrepareVideoCaptureAttributes(attributes.Receive(), 2))
+    return false;
+
+  attributes->SetString(MF_DEVSOURCE_ATTRIBUTE_SOURCE_TYPE_VIDCAP_SYMBOLIC_LINK,
+                        base::SysUTF8ToWide(sym_link).c_str());
+
+  return SUCCEEDED(MFCreateDeviceSource(attributes, source));
+}
+
+bool FormatFromGuid(const GUID& guid, VideoCaptureCapability::Format* format) {
+  struct {
+    const GUID& guid;
+    const VideoCaptureCapability::Format format;
+  } static const kFormatMap[] = {
+    { MFVideoFormat_I420, VideoCaptureCapability::kI420 },
+    { MFVideoFormat_YUY2, VideoCaptureCapability::kYUY2 },
+    { MFVideoFormat_UYVY, VideoCaptureCapability::kUYVY },
+    { MFVideoFormat_RGB24, VideoCaptureCapability::kRGB24 },
+    { MFVideoFormat_ARGB32, VideoCaptureCapability::kARGB },
+    { MFVideoFormat_MJPG, VideoCaptureCapability::kMJPEG },
+    { MFVideoFormat_YV12, VideoCaptureCapability::kYV12 },
+  };
+
+  for (int i = 0; i < arraysize(kFormatMap); ++i) {
+    if (kFormatMap[i].guid == guid) {
+      *format = kFormatMap[i].format;
+      return true;
+    }
+  }
+
+  return false;
+}
+
+bool GetFrameSize(IMFMediaType* type, int* width, int* height) {
+  UINT32 width32, height32;
+  if (FAILED(MFGetAttributeSize(type, MF_MT_FRAME_SIZE, &width32, &height32)))
+    return false;
+  *width = width32;
+  *height = height32;
+  return true;
+}
+
+bool GetFrameRate(IMFMediaType* type, int* frame_rate) {
+  UINT32 numerator, denominator;
+  if (FAILED(MFGetAttributeRatio(type, MF_MT_FRAME_RATE, &numerator,
+                                 &denominator))) {
+    return false;
+  }
+  *frame_rate = numerator / denominator;

[mflodman_chromium_OOO, 2012/11/29 20:00:02]

Protect agains denominator == 0? For DirectShow, that could be reported by some
drivers.

[tommi (sloooow) - chröme, 2012/11/30 07:04:06]

Gaa thanks!

+  return true;
+}
+
+bool FillCapabilitiesFromType(IMFMediaType* type,
+                              VideoCaptureCapability* capability) {
+  GUID type_guid;
+  if (FAILED(type->GetGUID(MF_MT_SUBTYPE, &type_guid)) ||
+      !FormatFromGuid(type_guid, &capability->color) ||
+      !GetFrameSize(type, &capability->width, &capability->height) ||
+      !GetFrameRate(type, &capability->frame_rate)) {
+    return false;
+  }
+
+  capability->expected_capture_delay = 0;  // Currently not used.
+  capability->interlaced = false;  // Currently not used.
+
+  return true;
+}
+
+HRESULT FillCapabilities(IMFSourceReader* source,
+                         CapabilityList* capabilities) {
+  DWORD stream_index = 0;
+  ScopedComPtr<IMFMediaType> type;
+  HRESULT hr;
+  while (SUCCEEDED(hr = source->GetNativeMediaType(
+      MF_SOURCE_READER_FIRST_VIDEO_STREAM, stream_index, type.Receive()))) {
+    VideoCaptureCapabilityWin capability(stream_index++);
+    if (FillCapabilitiesFromType(type, &capability))
+      capabilities->Add(capability);
+    type.Release();
+  }
+
+  if (SUCCEEDED(hr) && capabilities->empty())
+    hr = HRESULT_FROM_WIN32(ERROR_EMPTY);
+
+  return (hr == MF_E_NO_MORE_TYPES) ? S_OK : hr;
+}
+
+}  // namespace
+
+class MFReaderCallback
+    : public base::RefCountedThreadSafe<MFReaderCallback>,
+      public IMFSourceReaderCallback {
+ public:
+  MFReaderCallback(VideoCaptureDeviceMFWin* observer)
+      : observer_(observer), wait_event_(NULL) {
+  }
+
+  void SetSignalOnFlush(base::WaitableEvent* event) {
+    wait_event_ = event;
+  }
+
+  STDMETHOD(QueryInterface)(REFIID riid, void** object) {
+    if (riid != IID_IUnknown && riid != IID_IMFSourceReaderCallback)
+      return E_NOINTERFACE;
+    *object = static_cast<IMFSourceReaderCallback*>(this);
+    AddRef();
+    return S_OK;
+  }
+
+  STDMETHOD_(ULONG, AddRef)() {
+    base::RefCountedThreadSafe<MFReaderCallback>::AddRef();
+    return 1U;
+  }
+
+  STDMETHOD_(ULONG, Release)() {
+    base::RefCountedThreadSafe<MFReaderCallback>::Release();
+    return 1U;
+  }
+
+  STDMETHOD(OnReadSample)(HRESULT status, DWORD stream_index,
+      DWORD stream_flags, LONGLONG time_stamp, IMFSample* sample) {
+    base::Time stamp(base::Time::Now());
+    if (!sample) {
+      observer_->OnIncomingCapturedFrame(NULL, 0, stamp);
+      return S_OK;
+    }
+
+    DWORD count = 0;
+    sample->GetBufferCount(&count);

[mflodman_chromium_OOO, 2012/11/29 20:00:02]

When testing, have you ever seen multiple buffers in the same sample or will
that only happen in practice for oter cases, like media file read and decoding?

[tommi (sloooow) - chröme, 2012/11/30 07:04:06]

I've never seen that.  From what I've read it's unlikely to happen for webcams
but since the interface is the same for file based streams we've got to loop.

+
+    for (DWORD i = 0; i < count; ++i) {
+      ScopedComPtr<IMFMediaBuffer> buffer;
+      sample->GetBufferByIndex(i, buffer.Receive());
+      if (buffer) {
+        DWORD length = 0, max_length = 0;
+        BYTE* data = NULL;
+        buffer->Lock(&data, &max_length, &length);
+        observer_->OnIncomingCapturedFrame(data, length, stamp);
+        buffer->Unlock();
+      }
+    }
+    return S_OK;
+  }
+
+  STDMETHOD(OnFlush)(DWORD stream_index) {
+    if (wait_event_) {
+      wait_event_->Signal();
+      wait_event_ = NULL;
+    }
+    return S_OK;
+  }
+
+  STDMETHOD(OnEvent)(DWORD stream_index, IMFMediaEvent* event) {
+    NOTIMPLEMENTED();
+    return S_OK;
+  }
+
+ private:
+  friend class base::RefCountedThreadSafe<MFReaderCallback>;
+  ~MFReaderCallback() {}
+
+  VideoCaptureDeviceMFWin* observer_;
+  base::WaitableEvent* wait_event_;
+};
+
+// static
+void VideoCaptureDeviceMFWin::GetDeviceNames(Names* device_names) {
+  ScopedCoMem<IMFActivate*> devices;
+  UINT32 count;
+  if (!EnumerateVideoDevices(&devices, &count))
+    return;
+
+  HRESULT hr;
+  for (UINT32 i = 0; i < count; ++i) {
+    UINT32 name_size, id_size;
+    ScopedCoMem<wchar_t> name, id;
+    if (SUCCEEDED(hr = devices[i]->GetAllocatedString(
+            MF_DEVSOURCE_ATTRIBUTE_FRIENDLY_NAME, &name, &name_size)) &&
+        SUCCEEDED(hr = devices[i]->GetAllocatedString(
+            MF_DEVSOURCE_ATTRIBUTE_SOURCE_TYPE_VIDCAP_SYMBOLIC_LINK, &id,
+            &id_size))) {
+      std::wstring name_w(name, name_size), id_w(id, id_size);
+      Name device;
+      device.device_name = base::SysWideToUTF8(name_w);
+      device.unique_id = base::SysWideToUTF8(id_w);
+      device_names->push_back(device);
+    } else {
+      DLOG(WARNING) << "GetAllocatedString failed: " << std::hex << hr;
+    }
+    devices[i]->Release();
+  }
+}
+
+VideoCaptureDeviceMFWin::VideoCaptureDeviceMFWin(const Name& device_name)
+    : name_(device_name), observer_(NULL), capture_(0) {
+  DetachFromThread();
+}
+
+VideoCaptureDeviceMFWin::~VideoCaptureDeviceMFWin() {
+  DCHECK(CalledOnValidThread());
+}
+
+bool VideoCaptureDeviceMFWin::Init() {
+  DCHECK(CalledOnValidThread());
+  DCHECK(!reader_);
+
+  ScopedComPtr<IMFMediaSource> source;
+  if (!CreateVideoCaptureDevice(name_.unique_id.c_str(), source.Receive()))
+    return false;
+
+  ScopedComPtr<IMFAttributes> attributes;
+  MFCreateAttributes(attributes.Receive(), 1);
+  DCHECK(attributes);
+
+  callback_ = new MFReaderCallback(this);
+  attributes->SetUnknown(MF_SOURCE_READER_ASYNC_CALLBACK, callback_.get());
+
+  return SUCCEEDED(MFCreateSourceReaderFromMediaSource(source, attributes,
+                                                       reader_.Receive()));
+}
+
+void VideoCaptureDeviceMFWin::Allocate(
+    int width,
+    int height,
+    int frame_rate,
+    VideoCaptureDevice::EventHandler* observer) {
+  DCHECK(CalledOnValidThread());
+
+  base::AutoLock lock(lock_);
+
+  if (observer_) {
+    DCHECK_EQ(observer, observer_);
+    return;
+  }
+
+  observer_ = observer;
+  DCHECK_EQ(capture_, false);
+
+  CapabilityList capabilities;
+  HRESULT hr = S_OK;
+  if (!reader_ || FAILED(hr = FillCapabilities(reader_, &capabilities))) {
+    OnError(hr);
+    return;
+  }
+
+  const VideoCaptureCapabilityWin& found_capability =
+      capabilities.GetBestMatchedCapability(width, height, frame_rate);
+
+  ScopedComPtr<IMFMediaType> type;
+  if (FAILED(hr = reader_->GetNativeMediaType(
+          MF_SOURCE_READER_FIRST_VIDEO_STREAM, found_capability.stream_index,
+          type.Receive())) ||
+      FAILED(hr = reader_->SetCurrentMediaType(
+          MF_SOURCE_READER_FIRST_VIDEO_STREAM, NULL, type))) {
+    OnError(hr);
+    return;
+  }
+
+  observer_->OnFrameInfo(found_capability);
+}
+
+void VideoCaptureDeviceMFWin::Start() {
+  DCHECK(CalledOnValidThread());
+
+  base::AutoLock lock(lock_);
+  if (!capture_) {
+    capture_ = true;
+    HRESULT hr;
+    if (FAILED(hr = reader_->ReadSample(MF_SOURCE_READER_FIRST_VIDEO_STREAM, 0,
+                                        NULL, NULL, NULL, NULL))) {
+      OnError(hr);
+      capture_ = false;
+    }
+  }
+}
+
+void VideoCaptureDeviceMFWin::Stop() {
+  DCHECK(CalledOnValidThread());
+  base::WaitableEvent flushed(false, false);
+  bool wait = false;
+  {
+    base::AutoLock lock(lock_);
+    if (capture_) {
+      capture_ = false;
+      callback_->SetSignalOnFlush(&flushed);
+      HRESULT hr = reader_->Flush(MF_SOURCE_READER_ALL_STREAMS);
+      wait = SUCCEEDED(hr);
+      if (!wait) {
+        callback_->SetSignalOnFlush(NULL);
+        OnError(hr);
+      }
+    }
+  }
+
+  if (wait)
+    flushed.Wait();
+}
+
+void VideoCaptureDeviceMFWin::DeAllocate() {
+  DCHECK(CalledOnValidThread());
+
+  Stop();
+
+  base::AutoLock lock(lock_);
+  observer_ = NULL;
+}
+
+const VideoCaptureDevice::Name& VideoCaptureDeviceMFWin::device_name() {
+  DCHECK(CalledOnValidThread());
+  return name_;
+}
+
+void VideoCaptureDeviceMFWin::OnIncomingCapturedFrame(
+    const uint8* data,
+    int length,
+    const base::Time& time_stamp) {
+  base::AutoLock lock(lock_);
+  if (data && observer_)
+    observer_->OnIncomingCapturedFrame(data, length, time_stamp);
+
+  if (capture_) {
+    HRESULT hr = reader_->ReadSample(MF_SOURCE_READER_FIRST_VIDEO_STREAM, 0,
+                                     NULL, NULL, NULL, NULL);
+    if (FAILED(hr)) {
+      // If running the *VideoCap* unit tests on repeat, this can sometimes
+      // fail with HRESULT_FROM_WINHRESULT_FROM_WIN32(ERROR_INVALID_FUNCTION).
+      // It's not clear to me why this is, but it is possible that it has
+      // something to do with this bug:
+      // http://support.microsoft.com/kb/979567
+      OnError(hr);
+    }
+  }
+}
+
+void VideoCaptureDeviceMFWin::OnError(HRESULT hr) {
+  DLOG(ERROR) << "VideoCaptureDeviceMFWin: " << std::hex << hr;
+  if (observer_)
+    observer_->OnError();
+}
+
+}  // namespace media