blackmagic SDK in c#
i am attempting to capture 720p from one a blackmagic intensity pro cards using the newest SDK (june 2011) on windows7 64x and with C# + VS 2010 express.
i have successfully compiled and run a program that captures frames at YUV however, capture stops after 56 frames (the callback function stops being called). i am wondering if i am missing something simple here? especially given that i am almost there - i get frames with the correct content at the correct size etc but only for a brief time.
also some other information that may be relevant:
- if i unplug the camera capture does not stop
- i have also tried this at 1080i and PAL and the same happens
- same thing happens even if the VideoInputFrameArrived function is empty (i.e. with just a frame counter in it)
here is the code:
public partial class MainWindow : Window , IDeckLinkInputCallback
{
private IDeckLinkIterator _deckLinkIterator;
private List<IDeckLink> _deckLinkList = new List<IDeckLink>();
private IDeckLink _currentDevice=null;
private IDeckLinkInput _deckLinkInput = null;
private int _width=1280;
private int _height=720;
private WriteableBitmap _writeableBitmap =null;
IntPtr _tempRGBData;
byte[] _tempRGBDataBytes;
DispatcherTimer _timer = new DispatcherTimer();
public MainWindow()
{
InitializeComponent();
}
Random _random = new Random();
void _timer_Tick(object sender, EventArgs e)
{
_random.NextBytes(_tempRGBDataBytes);
_writeableBitmap.WritePixels(new Int32Rect(0, 0, _width, _height),_tempRGBData, _height * _width * 3, _width * 3);
}
private void Window_Loaded(object sender, RoutedEventArgs e)
{
_writeableBitmap = new WriteableBitmap(_width, _height, 72, 27, PixelFormats.Bgr24, null);
_captureImage.Source = _writeableBitmap;
_tempRGBData = Marshal.AllocHGlobal(3 * _width * _height * Marshal.SizeOf(typeof(byte)));
_tempRGBDataBytes = new byte[3 * _width * _height];
_deckLinkIterator = new CDeckLinkIterator();
IDeckLink dl=null;
while(true)
{
_deckLinkIterator.Next(out dl);
if(dl==null)
{
break;
}
else
{
_deckLinkList.Add(dl);
}
}
foreach (IDeckLink device in _deckLinkList)
{
String name;
device.GetModelName(out name);
Console.WriteLine("" + name);
}
_currentDevice = _deckLinkList[1];
_deckLinkInput = (IDeckLinkInput)_currentDevice;
uint frameCount=0;
_deckLinkInput.GetAvailableVideoFrameCount(out frameCount);
Console.WriteLine("available frame count: " + frameCount);
IDeckLinkDisplayModeIterator displayIterator=null;
_deckLinkInput.GetDisplayModeIterator(out displayIterator);
_BMDDisplayModeSupport displayModeSupport;
IDeckLinkDisplayMode displayMode=null;
_BMDDisplayMode setDisplayMode = _BMDDisplayMode.bmdModeHD720p50;
_BMDPixelFormat setPixelFormat = _BMDPixelFormat.bmdFormat8BitYUV;
_BMDVideoInputFlags setInputFlag = _BMDVideoInputFlags.bmdVideoInputFl开发者_JAVA技巧agDefault;
_deckLinkInput.DoesSupportVideoMode(setDisplayMode, setPixelFormat, setInputFlag, out displayModeSupport, out displayMode);
try
{
//_deckLinkInput.DisableAudioInput();
_deckLinkInput.EnableVideoInput(setDisplayMode, setPixelFormat, setInputFlag);
}
catch (Exception em)
{
Console.WriteLine("deck link init failed: " + em.Message);
}
_deckLinkInput.SetCallback(this);
Console.WriteLine("done!");
_timer.Interval = TimeSpan.FromSeconds(1f / 30f);
_timer.Tick += new EventHandler(_timer_Tick);
_timer.Start();
}
int frameCount = 0;
public void VideoInputFrameArrived(IDeckLinkVideoInputFrame video, IDeckLinkAudioInputPacket audio)
{
//get image data
IntPtr pData;
video.GetBytes(out pData);
//keeping it simple so just counting frames - this gets called 56 times then stops
Console.WriteLine("video frame arrived!! " + frameCount);
frameCount++;
}
public void VideoInputFormatChanged(_BMDVideoInputFormatChangedEvents events, IDeckLinkDisplayMode displayMode, _BMDDetectedVideoInputFormatFlags flags)
{
Console.WriteLine("video format changed!!");
}
//start stream
private void button1_Click(object sender, RoutedEventArgs e)
{
_deckLinkInput.StartStreams();
}
//stop stream
private void button2_Click(object sender, RoutedEventArgs e)
{
_deckLinkInput.StopStreams();
}
private void button4_Click(object sender, RoutedEventArgs e)
{
_deckLinkInput.PauseStreams();
}
private void button3_Click(object sender, RoutedEventArgs e)
{
_deckLinkInput.FlushStreams();
}
}
i've managed to solved this problem with the help of blackmagic tech support
the solution is to insert this line at the end of the callback function:
System.Runtime.InteropServices.Marshal.ReleaseComObject(video);
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