c＃中的blackmagic SDK
我试图在Windows7 64x和C＃+ VS 2010 express上使用最新的SDK（2011年6月）从一张blackmagic强度专业卡中捕获720p。
我已经成功编译并运行了一个在YUV捕获帧的程序，但是在56帧之后捕获停止（回调函数停止被调用）。 我想知道我在这里想念一些简单的东西吗？ 特别是考虑到我几乎就在那里 – 我得到的帧数正确，大小正确，但只有很短的时间。
还有一些可能相关的其他信息：
- 如果我拔下相机捕捉不停止
- 我也试过1080i和PAL，同样的事情发生了
- 即使VideoInputFrameArrived函数为空（即只有一个帧计数器），也会发生同样的事情
这是代码：
public partial class MainWindow : Window , IDeckLinkInputCallback { private IDeckLinkIterator _deckLinkIterator; private List _deckLinkList = new List(); 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.bmdVideoInputFlagDefault; _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(); } } 我已经设法在blackmagic技术支持的帮助下解决了这个问题
解决方案是在回调函数的末尾插入此行：
System.Runtime.InteropServices.Marshal.ReleaseComObject(video);