vidinput_v4l2.cxx

安装 H323需要的pwlib库

  struct v4l2_requestbuffers reqbuf;
  reqbuf.count = 1; // we shouldn't need more
  reqbuf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
  reqbuf.memory = V4L2_MEMORY_MMAP;

  if (::ioctl(videoFd, VIDIOC_REQBUFS, &reqbuf) < 0 ||
      reqbuf.count < 1 ||
      reqbuf.count > NUM_VIDBUF) {
    PTRACE(3,"PVidInDev\tREQBUFS failed : " << ::strerror(errno));
    return FALSE;
  }

  struct v4l2_buffer buf;
  memset(&buf, 0, sizeof(buf));
  buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
  
  videoBufferCount = reqbuf.count;
  for (buf.index = 0; buf.index < videoBufferCount; buf.index++) {
    if (::ioctl(videoFd, VIDIOC_QUERYBUF, &buf) < 0) {
      PTRACE(3,"PVidInDev\tQUERYBUF failed : " << ::strerror(errno));
      return FALSE;
    }

    if ((videoBuffer[buf.index] = (BYTE *)::mmap(0, buf.length, PROT_READ|PROT_WRITE, MAP_SHARED, videoFd, buf.m.offset)) == MAP_FAILED) {
      PTRACE(3,"PVidInDev\tmmap failed : " << ::strerror(errno));
      return FALSE;
    }
  }

  isMapped = TRUE;

  PTRACE(7,"PVidInDev\tset mapping for " << videoBufferCount << " buffers, fd=" << videoFd);


  return TRUE;
}


void PVideoInputV4l2Device::ClearMapping()
{
  if (!canStream) // 'isMapped' wouldn't handle partial mappings
    return;

  struct v4l2_buffer buf;
  buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;

  for (buf.index = 0; ; buf.index++) {
    if (::ioctl(videoFd, VIDIOC_QUERYBUF, &buf) < 0)
      break;

    ::munmap(videoBuffer[buf.index], buf.length);
  }

  isMapped = FALSE;

  PTRACE(7,"PVidInDev\tclear mapping, fd=" << videoFd);
}


BOOL PVideoInputV4l2Device::GetFrame(PBYTEArray & frame)
{
  PINDEX returned;
  if (!GetFrameData(frame.GetPointer(GetMaxFrameBytes()), &returned))
    return FALSE;

  frame.SetSize(returned);
  return TRUE;
}


BOOL PVideoInputV4l2Device::GetFrameData(BYTE * buffer, PINDEX * bytesReturned)
{
  PTRACE(1,"PVidInDev\tGetFrameData()");

  if (frameRate>0) {
    PTimeInterval delay;

    do {
      if (!GetFrameDataNoDelay(buffer, bytesReturned))
	return FALSE;

      delay = PTime() - previousFrameTime;
    } while (delay.GetMilliSeconds() < msBetweenFrames);

    previousFrameTime = PTime();

    return TRUE;
  }

  return GetFrameDataNoDelay(buffer, bytesReturned);
}


BOOL PVideoInputV4l2Device::GetFrameDataNoDelay(BYTE * buffer, PINDEX * bytesReturned)
{
  PTRACE(1,"PVidInDev\tGetFrameDataNoDelay()\tstarted:" << started << "  canSelect:" << canSelect);

  if (!started)
    return NormalReadProcess(buffer, bytesReturned);

  struct v4l2_buffer buf;

  buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
  buf.index = 0;
  if (::ioctl(videoFd, VIDIOC_DQBUF, &buf) < 0) {
    PTRACE(1,"PVidInDev\tDQBUF failed : " << ::strerror(errno));
    return FALSE;
  }

  // If converting on the fly do it from frame store to output buffer,
  // otherwise do straight copy.
  if (converter != NULL)
    converter->Convert(videoBuffer[buf.index], buffer, bytesReturned);
  else {
    memcpy(buffer, videoBuffer[buf.index], buf.bytesused);
    if (bytesReturned != NULL)
      *bytesReturned = buf.bytesused;
  }

  PTRACE(8,"PVidInDev\tget frame data of " << buf.bytesused << "bytes, fd=" << videoFd);

  // requeue the buffer
  if (::ioctl(videoFd, VIDIOC_QBUF, &buf) < 0) {
    PTRACE(1,"PVidInDev\tQBUF failed : " << ::strerror(errno));
  }

  return TRUE;
}


// This video device does not support memory mapping - so use
// normal read process to extract a frame of video data.
BOOL PVideoInputV4l2Device::NormalReadProcess(BYTE * buffer, PINDEX * bytesReturned)
{ 
  if (!canRead)
    return FALSE;

  ssize_t bytesRead;

  do
    bytesRead = ::read(videoFd, buffer, frameBytes);
  while (bytesRead < 0 && errno == EINTR);

  if (bytesRead < 0) {
    
    PTRACE(1,"PVidInDev\tread failed (read = "<<bytesRead<< " expected " << frameBytes <<")");
    bytesRead = frameBytes;
  }

  if ((PINDEX)bytesRead != frameBytes) {
    PTRACE(1,"PVidInDev\tread returned fewer bytes than expected");
    // May result from a compressed format, otherwise indicates an error.
  }

  if (converter != NULL)
    return converter->ConvertInPlace(buffer, bytesReturned);

  if (bytesReturned != NULL)
    *bytesReturned = (PINDEX)bytesRead;

  return TRUE;
}

BOOL PVideoInputV4l2Device::VerifyHardwareFrameSize(unsigned width,
						    unsigned height)
{
  struct v4l2_format videoFormat;
  videoFormat.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;

  // get the frame size
  if (::ioctl(videoFd, VIDIOC_G_FMT, &videoFormat) < 0) {
    PTRACE(1,"PVidInDev\tG_FMT failed : " << ::strerror(errno));
    return FALSE;
  }

  videoFormat.fmt.pix.width = width;
  videoFormat.fmt.pix.height = height;

  // set the frame size
  if (::ioctl(videoFd, VIDIOC_S_FMT, &videoFormat) < 0) {
    PTRACE(1,"PVidInDev\tS_FMT failed : " << ::strerror(errno));
    PTRACE(1,"\tused frame size of " << videoFormat.fmt.pix.width << "x" << videoFormat.fmt.pix.height);
    return FALSE;
  }

  // get the frame size again to be careful about broken drivers
  if (::ioctl(videoFd, VIDIOC_G_FMT, &videoFormat) < 0) {
    PTRACE(1,"PVidInDev\tG_FMT failed : " << ::strerror(errno));
    return FALSE;
  }

  if ((videoFormat.fmt.pix.width != width) || (videoFormat.fmt.pix.height != height)) {
    PTRACE(3,"PVidInDev\tframe size mismatch.");
    // allow the device to return actual frame size
    PVideoDevice::SetFrameSize(videoFormat.fmt.pix.width, videoFormat.fmt.pix.height);
    return FALSE;
  }

  frameBytes = videoFormat.fmt.pix.sizeimage;
  return TRUE;
}

int PVideoInputV4l2Device::GetBrightness() 
{ 
  if (!IsOpen())
    return -1;

  struct v4l2_control c;
  c.id = V4L2_CID_BRIGHTNESS;

  if (::ioctl(videoFd, VIDIOC_G_CTRL, &c) < 0)
    return -1;

  frameBrightness = c.value;
  return frameBrightness; 
}

int PVideoInputV4l2Device::GetWhiteness() 
{ 
  if (!IsOpen())
    return -1;

  struct v4l2_control c;
  c.id = V4L2_CID_WHITENESS;

  if (::ioctl(videoFd, VIDIOC_G_CTRL, &c) < 0)
    return -1;

  frameWhiteness = c.value;
  return frameWhiteness;
}

int PVideoInputV4l2Device::GetColour() 
{ 
  if (!IsOpen())
    return -1;

  struct v4l2_control c;
  c.id = V4L2_CID_SATURATION;

  if (::ioctl(videoFd, VIDIOC_G_CTRL, &c) < 0)
    return -1;

  frameColour = c.value;
  return frameColour; 
}

int PVideoInputV4l2Device::GetContrast() 
{
  if (!IsOpen())
    return -1;

  struct v4l2_control c;
  c.id = V4L2_CID_CONTRAST;

  if (::ioctl(videoFd, VIDIOC_G_CTRL, &c) < 0)
    return -1;

  frameContrast = c.value;
  return frameContrast; 
}

int PVideoInputV4l2Device::GetHue() 
{
  if (!IsOpen())
    return -1;

  struct v4l2_control c;
  c.id = V4L2_CID_HUE;

  if (::ioctl(videoFd, VIDIOC_G_CTRL, &c) < 0)
    return -1;

  frameHue = c.value;
  return frameHue; 
}

BOOL PVideoInputV4l2Device::SetBrightness(unsigned newBrightness) 
{ 
  if (!IsOpen())
    return FALSE;

  struct v4l2_queryctrl q;
  q.id = V4L2_CID_BRIGHTNESS;

  if (::ioctl(videoFd, VIDIOC_QUERYCTRL, &q) < 0)
    return FALSE;

  struct v4l2_control c;
  c.id = V4L2_CID_BRIGHTNESS;
  c.value = q.minimum + ((q.maximum-q.minimum) * newBrightness) >> 16;

  if (::ioctl(videoFd, VIDIOC_S_CTRL, &c) < 0)
    return FALSE;

  frameBrightness = newBrightness;
  return TRUE;
}

BOOL PVideoInputV4l2Device::SetWhiteness(unsigned newWhiteness) 
{ 
  if (!IsOpen())
    return FALSE;

  struct v4l2_queryctrl q;
  q.id = V4L2_CID_WHITENESS;

  if (::ioctl(videoFd, VIDIOC_QUERYCTRL, &q) < 0)
    return FALSE;

  struct v4l2_control c;
  c.id = V4L2_CID_WHITENESS;
  c.value = q.minimum + ((q.maximum-q.minimum) * newWhiteness) >> 16;

  if (::ioctl(videoFd, VIDIOC_S_CTRL, &c) < 0)
    return FALSE;

  frameWhiteness = newWhiteness;
  return TRUE;
}

BOOL PVideoInputV4l2Device::SetColour(unsigned newColour) 
{ 
  if (!IsOpen())
    return FALSE;

  struct v4l2_queryctrl q;
  q.id = V4L2_CID_SATURATION;

  if (::ioctl(videoFd, VIDIOC_QUERYCTRL, &q) < 0)
    return FALSE;

  struct v4l2_control c;
  c.id = V4L2_CID_SATURATION;
  c.value = q.minimum + ((q.maximum-q.minimum) * newColour) >> 16;

  if (::ioctl(videoFd, VIDIOC_S_CTRL, &c) < 0)
    return FALSE;

  frameColour = newColour;
  return TRUE;
}

BOOL PVideoInputV4l2Device::SetContrast(unsigned newContrast) 
{ 
  if (!IsOpen())
    return FALSE;

  struct v4l2_queryctrl q;
  q.id = V4L2_CID_CONTRAST;

  if (::ioctl(videoFd, VIDIOC_QUERYCTRL, &q) < 0)
    return FALSE;

  struct v4l2_control c;
  c.id = V4L2_CID_CONTRAST;
  c.value = q.minimum + ((q.maximum-q.minimum) * newContrast) >> 16;

  if (::ioctl(videoFd, VIDIOC_S_CTRL, &c) < 0)
    return FALSE;

  frameContrast = newContrast;
  return TRUE;
}

BOOL PVideoInputV4l2Device::SetHue(unsigned newHue) 
{
  if (!IsOpen())
    return FALSE;

  struct v4l2_queryctrl q;
  q.id = V4L2_CID_HUE;

  if (::ioctl(videoFd, VIDIOC_QUERYCTRL, &q) < 0)
    return FALSE;

  struct v4l2_control c;
  c.id = V4L2_CID_HUE;
  c.value = q.minimum + ((q.maximum-q.minimum) * newHue) >> 16;

  if (::ioctl(videoFd, VIDIOC_S_CTRL, &c) < 0)
    return FALSE;

  frameHue=newHue;
  return TRUE;
}

BOOL PVideoInputV4l2Device::GetParameters (int *whiteness, int *brightness, 
					   int *colour, int *contrast, int *hue)
{
  if (!IsOpen())
    return FALSE;

  struct v4l2_control c;

  c.id = V4L2_CID_WHITENESS;
  if (::ioctl(videoFd, VIDIOC_G_CTRL, &c) < 0)
    frameWhiteness = -1;
  else
    frameWhiteness = c.value;
  c.id = V4L2_CID_BRIGHTNESS;
  if (::ioctl(videoFd, VIDIOC_G_CTRL, &c) < 0)
    frameBrightness = -1;
  else
    frameBrightness = c.value;
  c.id = V4L2_CID_SATURATION;
  if (::ioctl(videoFd, VIDIOC_G_CTRL, &c) < 0)
    frameColour = -1;
  else
    frameColour = c.value;
  c.id = V4L2_CID_CONTRAST;
  if (::ioctl(videoFd, VIDIOC_G_CTRL, &c) < 0)
    frameContrast = -1;
  else
    frameContrast = c.value;
  c.id = V4L2_CID_HUE;
  if (::ioctl(videoFd, VIDIOC_G_CTRL, &c) < 0)
    frameHue = -1;
  else
    frameHue = c.value;

  *whiteness  = frameWhiteness;
  *brightness = frameBrightness;
  *colour     = frameColour;
  *contrast   = frameContrast;
  *hue        = frameHue;

  return TRUE;
}

BOOL PVideoInputV4l2Device::TestAllFormats()
{
  return TRUE;
}



// this is used to get more userfriendly names:

void
V4L2Names::Update()
{
  PTRACE(1,"Detecting V4L2 devices");
  PDirectory   procvideo2_4("/proc/video/dev");
  PDirectory   procvideo2_6("/sys/class/video4linux");
  PDirectory * procvideo;
  PString      entry;
  PStringList  devlist;
  PString      oldDevName;
  // Try and guess kernel version
  if (procvideo2_6.Exists()) {
    kernelVersion = K2_6;
    procvideo=&procvideo2_6;
  }
  else if (procvideo2_4.Exists()) {
    kernelVersion=K2_4;
    procvideo=&procvideo2_4;
  } 
  else {
    kernelVersion=KUNKNOWN;
    procvideo=0;
  }
  inputDeviceNames.RemoveAll (); // flush the previous run
  if (procvideo) {
    PTRACE(2,"PV4L2Plugin\tdetected device metadata at "<<*procvideo);
    if ((kernelVersion==K2_6 && procvideo->Open(PFileInfo::SubDirectory) || 
	 (procvideo->Open(PFileInfo::RegularFile)))) {
      do {
        entry = procvideo->GetEntryName();
	if ((entry.Left(5) == "video")) {
	  PString thisDevice = "/dev/" + entry;
	  int videoFd=::open((const char *)thisDevice, O_RDONLY | O_NONBLOCK);
	  if ((videoFd > 0) || (errno == EBUSY)) {
	    BOOL valid = FALSE;
	    struct v4l2_capability videoCaps;
	    memset(&videoCaps,0,sizeof(videoCaps));
	    if ((errno == EBUSY) ||
		(::ioctl(videoFd, VIDIOC_QUERYCAP, &videoCaps) >= 0 &&
		 (videoCaps.capabilities & V4L2_CAP_VIDEO_CAPTURE))) {
	      PTRACE(1,"PV4L2Plugin\tdetected capture device " << videoCaps.card);
	      valid = TRUE;
	    }
	    else {
	      PTRACE(1,"PV4L2Plugin\t" << thisDevice << "is not deemed valid");
	    }
	    if (videoFd>0)
	      ::close(videoFd);
	    if(valid)
	      inputDeviceNames += thisDevice;
	  }
	  else {
	    PTRACE(1,"PV4L2Plugin\tcould not open " << thisDevice);
	  }
	}
      } while (procvideo->Next());
    }
  }
  else {
    PTRACE(1,"Unable to detect v4l2 directory");
  }
  if (inputDeviceNames.GetSize() == 0) {
    POrdinalToString vid;
    ReadDeviceDirectory("/dev/", vid);

    for (PINDEX i = 0; i < vid.GetSize(); i++) {
      PINDEX cardnum = vid.GetKeyAt(i);
      int fd = ::open(vid[cardnum], O_RDONLY | O_NONBLOCK);
      if ((fd >= 0) || (errno == EBUSY)) {
	if (fd >= 0)
	  ::close(fd);
	inputDeviceNames += vid[cardnum];
      }
    }
  }
  PopulateDictionary();
}

PString V4L2Names::BuildUserFriendly(PString devname)
{
  PString Result;

  int fd = ::open((const char *)devname, O_RDONLY);
  if(fd < 0) {
    return devname;
  }

  struct v4l2_capability videocap;
  memset(&videocap,0,sizeof(videocap));
  if (::ioctl(fd, VIDIOC_QUERYCAP, &videocap) < 0)  {
      ::close(fd);
      return devname;
    }
  
  ::close(fd);
  PString ufname((const char*)videocap.card);

  return ufname;
}

// End Of File ///////////////////////////////////////////////////////////////