modules/video_capture/video_capture_impl.cc

/*
 *  Copyright (c) 2012 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/modules/video_capture/video_capture_impl.h"

#include <stdlib.h>

#include "webrtc/api/video/i420_buffer.h"
#include "webrtc/common_video/libyuv/include/webrtc_libyuv.h"
#include "webrtc/modules/include/module_common_types.h"
#include "webrtc/modules/video_capture/video_capture_config.h"
#include "webrtc/rtc_base/logging.h"
#include "webrtc/rtc_base/refcount.h"
#include "webrtc/rtc_base/timeutils.h"
#include "webrtc/rtc_base/trace_event.h"
#include "webrtc/system_wrappers/include/clock.h"

namespace webrtc {
namespace videocapturemodule {
rtc::scoped_refptr<VideoCaptureModule> VideoCaptureImpl::Create(
    VideoCaptureExternal*& externalCapture) {
  rtc::scoped_refptr<VideoCaptureImpl> implementation(
      new rtc::RefCountedObject<VideoCaptureImpl>());
  externalCapture = implementation.get();
  return implementation;
}

const char* VideoCaptureImpl::CurrentDeviceName() const {
  return _deviceUniqueId;
}

// static
int32_t VideoCaptureImpl::RotationFromDegrees(int degrees,
                                              VideoRotation* rotation) {
  switch (degrees) {
    case 0:
      *rotation = kVideoRotation_0;
      return 0;
    case 90:
      *rotation = kVideoRotation_90;
      return 0;
    case 180:
      *rotation = kVideoRotation_180;
      return 0;
    case 270:
      *rotation = kVideoRotation_270;
      return 0;
    default:
      return -1;;
  }
}

// static
int32_t VideoCaptureImpl::RotationInDegrees(VideoRotation rotation,
                                            int* degrees) {
  switch (rotation) {
    case kVideoRotation_0:
      *degrees = 0;
      return 0;
    case kVideoRotation_90:
      *degrees = 90;
      return 0;
    case kVideoRotation_180:
      *degrees = 180;
      return 0;
    case kVideoRotation_270:
      *degrees = 270;
      return 0;
  }
  return -1;
}

VideoCaptureImpl::VideoCaptureImpl()
    : _deviceUniqueId(NULL),
      _requestedCapability(),
      _lastProcessTimeNanos(rtc::TimeNanos()),
      _lastFrameRateCallbackTimeNanos(rtc::TimeNanos()),
      _dataCallBack(NULL),
      _lastProcessFrameTimeNanos(rtc::TimeNanos()),
      _rotateFrame(kVideoRotation_0),
      apply_rotation_(false) {
    _requestedCapability.width = kDefaultWidth;
    _requestedCapability.height = kDefaultHeight;
    _requestedCapability.maxFPS = 30;
    _requestedCapability.videoType = VideoType::kI420;
    memset(_incomingFrameTimesNanos, 0, sizeof(_incomingFrameTimesNanos));
}

VideoCaptureImpl::~VideoCaptureImpl()
{
    DeRegisterCaptureDataCallback();
    if (_deviceUniqueId)
        delete[] _deviceUniqueId;
}

void VideoCaptureImpl::RegisterCaptureDataCallback(
    rtc::VideoSinkInterface<VideoFrame>* dataCallBack) {
    rtc::CritScope cs(&_apiCs);
    _dataCallBack = dataCallBack;
}

void VideoCaptureImpl::DeRegisterCaptureDataCallback() {
    rtc::CritScope cs(&_apiCs);
    _dataCallBack = NULL;
}
int32_t VideoCaptureImpl::DeliverCapturedFrame(VideoFrame& captureFrame) {
  UpdateFrameCount();  // frame count used for local frame rate callback.

  if (_dataCallBack) {
    _dataCallBack->OnFrame(captureFrame);
  }

  return 0;
}

int32_t VideoCaptureImpl::IncomingFrame(
    uint8_t* videoFrame,
    size_t videoFrameLength,
    const VideoCaptureCapability& frameInfo,
    int64_t captureTime/*=0*/)
{
    rtc::CritScope cs(&_apiCs);

    const int32_t width = frameInfo.width;
    const int32_t height = frameInfo.height;

    TRACE_EVENT1("webrtc", "VC::IncomingFrame", "capture_time", captureTime);

    // Not encoded, convert to I420.
    if (frameInfo.videoType != VideoType::kMJPEG &&
        CalcBufferSize(frameInfo.videoType, width, abs(height)) !=
            videoFrameLength) {
      LOG(LS_ERROR) << "Wrong incoming frame length.";
      return -1;
    }

    int stride_y = width;
    int stride_uv = (width + 1) / 2;
    int target_width = width;
    int target_height = height;

    // SetApplyRotation doesn't take any lock. Make a local copy here.
    bool apply_rotation = apply_rotation_;

    if (apply_rotation) {
      // Rotating resolution when for 90/270 degree rotations.
      if (_rotateFrame == kVideoRotation_90 ||
          _rotateFrame == kVideoRotation_270) {
        target_width = abs(height);
        target_height = width;
      }
    }

    // Setting absolute height (in case it was negative).
    // In Windows, the image starts bottom left, instead of top left.
    // Setting a negative source height, inverts the image (within LibYuv).

    // TODO(nisse): Use a pool?
    rtc::scoped_refptr<I420Buffer> buffer = I420Buffer::Create(
        target_width, abs(target_height), stride_y, stride_uv, stride_uv);
    const int conversionResult = ConvertToI420(
        frameInfo.videoType, videoFrame, 0, 0,  // No cropping
        width, height, videoFrameLength,
        apply_rotation ? _rotateFrame : kVideoRotation_0, buffer.get());
    if (conversionResult < 0) {
      LOG(LS_ERROR) << "Failed to convert capture frame from type "
                    << static_cast<int>(frameInfo.videoType) << "to I420.";
      return -1;
    }

    VideoFrame captureFrame(buffer, 0, rtc::TimeMillis(),
                            !apply_rotation ? _rotateFrame : kVideoRotation_0);
    captureFrame.set_ntp_time_ms(captureTime);

    DeliverCapturedFrame(captureFrame);

    return 0;
}

int32_t VideoCaptureImpl::SetCaptureRotation(VideoRotation rotation) {
  rtc::CritScope cs(&_apiCs);
  _rotateFrame = rotation;
  return 0;
}

bool VideoCaptureImpl::SetApplyRotation(bool enable) {
  // We can't take any lock here as it'll cause deadlock with IncomingFrame.

  // The effect of this is the last caller wins.
  apply_rotation_ = enable;
  return true;
}

void VideoCaptureImpl::UpdateFrameCount() {
  if (_incomingFrameTimesNanos[0] / rtc::kNumNanosecsPerMicrosec == 0) {
    // first no shift
  } else {
    // shift
    for (int i = (kFrameRateCountHistorySize - 2); i >= 0; --i) {
      _incomingFrameTimesNanos[i + 1] = _incomingFrameTimesNanos[i];
    }
  }
  _incomingFrameTimesNanos[0] = rtc::TimeNanos();
}

uint32_t VideoCaptureImpl::CalculateFrameRate(int64_t now_ns) {
  int32_t num = 0;
  int32_t nrOfFrames = 0;
  for (num = 1; num < (kFrameRateCountHistorySize - 1); ++num) {
    if (_incomingFrameTimesNanos[num] <= 0 ||
        (now_ns - _incomingFrameTimesNanos[num]) /
                rtc::kNumNanosecsPerMillisec >
            kFrameRateHistoryWindowMs) {  // don't use data older than 2sec
      break;
    } else {
      nrOfFrames++;
    }
  }
  if (num > 1) {
    int64_t diff = (now_ns - _incomingFrameTimesNanos[num - 1]) /
                   rtc::kNumNanosecsPerMillisec;
    if (diff > 0) {
      return uint32_t((nrOfFrames * 1000.0f / diff) + 0.5f);
    }
  }

  return nrOfFrames;
}
}  // namespace videocapturemodule
}  // namespace webrtc