使用FireWire的QTCaptureDecompressedVideoOutput

Question

我正在尝试为Quartz Composer创建一个从FireWire输入捕获的自定义补丁。我可以打开设备并成功添加输入。我甚至根据QTKit文档禁用了音频输入。我怀疑我的问题要么是添加输出(尽管它添加时没有错误)。每次框架运行时，当imageBuffer显示为空时，它就会崩溃。它没有尺寸或任何东西。我使用的是文档中的标准captureOutput:didOutputVideoFrame:withSampleBuffer:fromConnection。

   [mCaptureDecompressedVideoOutput release];
    mCaptureDecompressedVideoOutput = [[QTCaptureDecompressedVideoOutput alloc] init];
    NSLog(@"allocated mCaptureDecompressedVideoOutput");
    [mCaptureDecompressedVideoOutput setPixelBufferAttributes:
     [NSDictionary dictionaryWithObjectsAndKeys:
      [NSNumber numberWithBool:YES], kCVPixelBufferOpenGLCompatibilityKey,
      [NSNumber numberWithLong:k32ARGBPixelFormat], kCVPixelBufferPixelFormatTypeKey, nil]];


    [mCaptureDecompressedVideoOutput setDelegate:self];
    success = [mCaptureSession addOutput:mCaptureDecompressedVideoOutput error:&error];

    if (!success) {
        NSLog(@"Failed to add output");
            self.outputImage = nil; 
        if (mCaptureSession) {
            [mCaptureSession release];
            mCaptureSession= nil;
        }
        if (mCaptureDeviceInput) {
            [mCaptureDeviceInput release];
            mCaptureDeviceInput= nil;
        }
        if (mCaptureDecompressedVideoOutput) {
            [mCaptureDecompressedVideoOutput release];
            mCaptureDecompressedVideoOutput= nil;
        }
        return YES;
    }

    [mCaptureSession startRunning]; 
        _currentDevice= self.inputDevice;
    }

    CVImageBufferRef imageBuffer = CVBufferRetain(mCurrentImageBuffer);

if (imageBuffer) {
    CVPixelBufferLockBaseAddress(imageBuffer, 0);
    NSLog(@"ColorSpace: %@", CVImageBufferGetColorSpace(imageBuffer));

    id provider= [context outputImageProviderFromBufferWithPixelFormat:QCPlugInPixelFormatARGB8           
                                                            pixelsWide:CVPixelBufferGetWidth(imageBuffer)
                                                            pixelsHigh:CVPixelBufferGetHeight(imageBuffer)
                                                           baseAddress:CVPixelBufferGetBaseAddress(imageBuffer)
                                                           bytesPerRow:CVPixelBufferGetBytesPerRow(imageBuffer)
                                                       releaseCallback:_BufferReleaseCallback
                                                        releaseContext:imageBuffer
                                                            colorSpace:CVImageBufferGetColorSpace(imageBuffer)
                                                      shouldColorMatch:YES];

我能做错什么呢？此代码适用于纯视频输入，但不适用于FireWire (多路复用)输入。

Answer 1

通过从mCaptureDecompressedVideoOutput中删除kCVPixelBufferOpenGLCompatibilityKey，我设法让这个补丁同时支持视频和多路复用输入。虽然这使得补丁可以在Quartz Composer中完美地工作，但我的目的是在CamTwist内部使用的组合中运行这个补丁，它似乎不需要OpenGL支持。现在，它只显示一个黑屏，带有wither或Muxed输入，就像它以前使用视频输入一样。因此，我要将我的CVImageBufferRef转换为OpenGL纹理，看看是否可以使用它

outputImageProviderFromTextureWithPixelFormat:pixelsWide:pixelsHigh:name:flipped:releaseCallback:releaseContext:colorSpace:shouldColorMatch