webrtc/media/engine/webrtcvideocapturer.cc

/*
 *  Copyright (c) 2011 The WebRTC project authors. All Rights Reserved.
 *
 *  Use of this source code is governed by a BSD-style license
 *  that can be found in the LICENSE file in the root of the source
 *  tree. An additional intellectual property rights grant can be found
 *  in the file PATENTS.  All contributing project authors may
 *  be found in the AUTHORS file in the root of the source tree.
 */

#include "webrtc/media/engine/webrtcvideocapturer.h"

#include "webrtc/base/arraysize.h"
#include "webrtc/base/bind.h"
#include "webrtc/base/checks.h"
#include "webrtc/base/criticalsection.h"
#include "webrtc/base/logging.h"
#include "webrtc/base/safe_conversions.h"
#include "webrtc/base/thread.h"
#include "webrtc/base/timeutils.h"

#include "webrtc/base/win32.h"  // Need this to #include the impl files.
#include "webrtc/modules/video_capture/video_capture_factory.h"
#include "webrtc/system_wrappers/include/field_trial.h"

namespace cricket {

struct kVideoFourCCEntry {
  uint32_t fourcc;
  webrtc::RawVideoType webrtc_type;
};

// This indicates our format preferences and defines a mapping between
// webrtc::RawVideoType (from video_capture_defines.h) to our FOURCCs.
static kVideoFourCCEntry kSupportedFourCCs[] = {
  { FOURCC_I420, webrtc::kVideoI420 },   // 12 bpp, no conversion.
  { FOURCC_YV12, webrtc::kVideoYV12 },   // 12 bpp, no conversion.
  { FOURCC_YUY2, webrtc::kVideoYUY2 },   // 16 bpp, fast conversion.
  { FOURCC_UYVY, webrtc::kVideoUYVY },   // 16 bpp, fast conversion.
  { FOURCC_NV12, webrtc::kVideoNV12 },   // 12 bpp, fast conversion.
  { FOURCC_NV21, webrtc::kVideoNV21 },   // 12 bpp, fast conversion.
  { FOURCC_MJPG, webrtc::kVideoMJPEG },  // compressed, slow conversion.
  { FOURCC_ARGB, webrtc::kVideoARGB },   // 32 bpp, slow conversion.
  { FOURCC_24BG, webrtc::kVideoRGB24 },  // 24 bpp, slow conversion.
};

class WebRtcVcmFactory : public WebRtcVcmFactoryInterface {
 public:
  virtual rtc::scoped_refptr<webrtc::VideoCaptureModule> Create(
      const char* device) {
    return webrtc::VideoCaptureFactory::Create(device);
  }
  virtual webrtc::VideoCaptureModule::DeviceInfo* CreateDeviceInfo() {
    return webrtc::VideoCaptureFactory::CreateDeviceInfo();
  }
  virtual void DestroyDeviceInfo(webrtc::VideoCaptureModule::DeviceInfo* info) {
    delete info;
  }
};

static bool CapabilityToFormat(const webrtc::VideoCaptureCapability& cap,
                               VideoFormat* format) {
  uint32_t fourcc = 0;
  for (size_t i = 0; i < arraysize(kSupportedFourCCs); ++i) {
    if (kSupportedFourCCs[i].webrtc_type == cap.rawType) {
      fourcc = kSupportedFourCCs[i].fourcc;
      break;
    }
  }
  if (fourcc == 0) {
    return false;
  }

  format->fourcc = fourcc;
  format->width = cap.width;
  format->height = cap.height;
  format->interval = VideoFormat::FpsToInterval(cap.maxFPS);
  return true;
}

static bool FormatToCapability(const VideoFormat& format,
                               webrtc::VideoCaptureCapability* cap) {
  webrtc::RawVideoType webrtc_type = webrtc::kVideoUnknown;
  for (size_t i = 0; i < arraysize(kSupportedFourCCs); ++i) {
    if (kSupportedFourCCs[i].fourcc == format.fourcc) {
      webrtc_type = kSupportedFourCCs[i].webrtc_type;
      break;
    }
  }
  if (webrtc_type == webrtc::kVideoUnknown) {
    return false;
  }

  cap->width = format.width;
  cap->height = format.height;
  cap->maxFPS = VideoFormat::IntervalToFps(format.interval);
  cap->rawType = webrtc_type;
  cap->interlaced = false;
  return true;
}

///////////////////////////////////////////////////////////////////////////
// Implementation of class WebRtcVideoCapturer
///////////////////////////////////////////////////////////////////////////

WebRtcVideoCapturer::WebRtcVideoCapturer()
    : factory_(new WebRtcVcmFactory),
      module_(nullptr),
      captured_frames_(0),
      start_thread_(nullptr),
      async_invoker_(nullptr) {}

WebRtcVideoCapturer::WebRtcVideoCapturer(WebRtcVcmFactoryInterface* factory)
    : factory_(factory),
      module_(nullptr),
      captured_frames_(0),
      start_thread_(nullptr),
      async_invoker_(nullptr) {}

WebRtcVideoCapturer::~WebRtcVideoCapturer() {}

bool WebRtcVideoCapturer::Init(const Device& device) {
  RTC_DCHECK(!start_thread_);
  if (module_) {
    LOG(LS_ERROR) << "The capturer is already initialized";
    return false;
  }

  webrtc::VideoCaptureModule::DeviceInfo* info = factory_->CreateDeviceInfo();
  if (!info) {
    return false;
  }

  // Find the desired camera, by name.
  // In the future, comparing IDs will be more robust.
  // TODO(juberti): Figure what's needed to allow this.
  int num_cams = info->NumberOfDevices();
  char vcm_id[256] = "";
  bool found = false;
  for (int index = 0; index < num_cams; ++index) {
    char vcm_name[256];
    if (info->GetDeviceName(index, vcm_name, arraysize(vcm_name), vcm_id,
                            arraysize(vcm_id)) != -1) {
      if (device.name == reinterpret_cast<char*>(vcm_name)) {
        found = true;
        break;
      }
    }
  }
  if (!found) {
    LOG(LS_WARNING) << "Failed to find capturer for id: " << device.id;
    factory_->DestroyDeviceInfo(info);
    return false;
  }

  // Enumerate the supported formats.
  // TODO(juberti): Find out why this starts/stops the camera...
  std::vector<VideoFormat> supported;
  int32_t num_caps = info->NumberOfCapabilities(vcm_id);
  for (int32_t i = 0; i < num_caps; ++i) {
    webrtc::VideoCaptureCapability cap;
    if (info->GetCapability(vcm_id, i, cap) != -1) {
      VideoFormat format;
      if (CapabilityToFormat(cap, &format)) {
        supported.push_back(format);
      } else {
        LOG(LS_WARNING) << "Ignoring unsupported WebRTC capture format "
                        << cap.rawType;
      }
    }
  }
  factory_->DestroyDeviceInfo(info);

  if (supported.empty()) {
    LOG(LS_ERROR) << "Failed to find usable formats for id: " << device.id;
    return false;
  }

  module_ = factory_->Create(vcm_id);
  if (!module_) {
    LOG(LS_ERROR) << "Failed to create capturer for id: " << device.id;
    return false;
  }

  // It is safe to change member attributes now.
  SetId(device.id);
  SetSupportedFormats(supported);

  return true;
}

bool WebRtcVideoCapturer::Init(
    const rtc::scoped_refptr<webrtc::VideoCaptureModule>& module) {
  RTC_DCHECK(!start_thread_);
  if (module_) {
    LOG(LS_ERROR) << "The capturer is already initialized";
    return false;
  }
  if (!module) {
    LOG(LS_ERROR) << "Invalid VCM supplied";
    return false;
  }
  // TODO(juberti): Set id and formats.
  module_ = module;
  return true;
}

bool WebRtcVideoCapturer::GetBestCaptureFormat(const VideoFormat& desired,
                                               VideoFormat* best_format) {
  if (!best_format) {
    return false;
  }

  if (!VideoCapturer::GetBestCaptureFormat(desired, best_format)) {
    // We maybe using a manually injected VCM which doesn't support enum.
    // Use the desired format as the best format.
    best_format->width = desired.width;
    best_format->height = desired.height;
    best_format->fourcc = FOURCC_I420;
    best_format->interval = desired.interval;
    LOG(LS_INFO) << "Failed to find best capture format,"
                 << " fall back to the requested format "
                 << best_format->ToString();
  }
  return true;
}
void WebRtcVideoCapturer::OnSinkWantsChanged(const rtc::VideoSinkWants& wants) {
  // Can't take lock here as this will cause deadlock with
  // OnIncomingCapturedFrame. In fact, the whole method, including methods it
  // calls, can't take lock.
  RTC_DCHECK(module_);

  if (webrtc::field_trial::FindFullName("WebRTC-CVO").find("Disabled") == 0)
    return;

  VideoCapturer::OnSinkWantsChanged(wants);
  bool result = module_->SetApplyRotation(wants.rotation_applied);
  RTC_CHECK(result);

  return;
}

CaptureState WebRtcVideoCapturer::Start(const VideoFormat& capture_format) {
  if (!module_) {
    LOG(LS_ERROR) << "The capturer has not been initialized";
    return CS_FAILED;
  }
  if (start_thread_) {
    LOG(LS_ERROR) << "The capturer is already running";
    RTC_DCHECK(start_thread_->IsCurrent())
        << "Trying to start capturer on different threads";
    return CS_FAILED;
  }

  start_thread_ = rtc::Thread::Current();
  RTC_DCHECK(!async_invoker_);
  async_invoker_.reset(new rtc::AsyncInvoker());
  captured_frames_ = 0;

  SetCaptureFormat(&capture_format);

  webrtc::VideoCaptureCapability cap;
  if (!FormatToCapability(capture_format, &cap)) {
    LOG(LS_ERROR) << "Invalid capture format specified";
    return CS_FAILED;
  }

  int64_t start = rtc::TimeMillis();
  module_->RegisterCaptureDataCallback(this);
  if (module_->StartCapture(cap) != 0) {
    LOG(LS_ERROR) << "Camera '" << GetId() << "' failed to start";
    module_->DeRegisterCaptureDataCallback();
    async_invoker_.reset();
    SetCaptureFormat(nullptr);
    start_thread_ = nullptr;
    return CS_FAILED;
  }

  LOG(LS_INFO) << "Camera '" << GetId() << "' started with format "
               << capture_format.ToString() << ", elapsed time "
               << rtc::TimeSince(start) << " ms";

  SetCaptureState(CS_RUNNING);
  return CS_STARTING;
}

void WebRtcVideoCapturer::Stop() {
  if (!start_thread_) {
    LOG(LS_ERROR) << "The capturer is already stopped";
    return;
  }
  RTC_DCHECK(start_thread_);
  RTC_DCHECK(start_thread_->IsCurrent());
  RTC_DCHECK(async_invoker_);
  if (IsRunning()) {
    // The module is responsible for OnIncomingCapturedFrame being called, if
    // we stop it we will get no further callbacks.
    module_->StopCapture();
  }
  module_->DeRegisterCaptureDataCallback();

  // TODO(juberti): Determine if the VCM exposes any drop stats we can use.
  double drop_ratio = 0.0;
  LOG(LS_INFO) << "Camera '" << GetId() << "' stopped after capturing "
               << captured_frames_ << " frames and dropping "
               << drop_ratio << "%";

  // Clear any pending async invokes (that OnIncomingCapturedFrame may have
  // caused).
  async_invoker_.reset();

  SetCaptureFormat(NULL);
  start_thread_ = nullptr;
  SetCaptureState(CS_STOPPED);
}

bool WebRtcVideoCapturer::IsRunning() {
  return (module_ != NULL && module_->CaptureStarted());
}

bool WebRtcVideoCapturer::GetPreferredFourccs(std::vector<uint32_t>* fourccs) {
  if (!fourccs) {
    return false;
  }

  fourccs->clear();
  for (size_t i = 0; i < arraysize(kSupportedFourCCs); ++i) {
    fourccs->push_back(kSupportedFourCCs[i].fourcc);
  }
  return true;
}

void WebRtcVideoCapturer::OnFrame(
    const webrtc::VideoFrame& sample) {
  // This can only happen between Start() and Stop().
  RTC_DCHECK(start_thread_);
  RTC_DCHECK(async_invoker_);

  ++captured_frames_;
  // Log the size and pixel aspect ratio of the first captured frame.
  if (1 == captured_frames_) {
    LOG(LS_INFO) << "Captured frame size "
                 << sample.width() << "x" << sample.height()
                 << ". Expected format " << GetCaptureFormat()->ToString();
  }

  VideoCapturer::OnFrame(sample, sample.width(), sample.height());
}

}  // namespace cricket