您可以使用此方法成功地同时录制视频和抓帧:
AVCaptureSession *captureSession = [AVCaptureSession new];
AVCaptureDevice *captureDevice = [AVCaptureDevice new];
AVCaptureDeviceInput *deviceInput = [AVCaptureDeviceInput new];
AVCaptureVideoDataOutput *output = [AVCaptureVideoDataOutput new];
NSDictionary *outputSettings = [NSDictionary dictionaryWithObjectsAndKeys:
[NSNumber numberWithInt:640], AVVideoWidthKey, [NSNumber numberWithInt:480], AVVideoHeightKey, AVVideoCodecH264, AVVideoCodecKey, nil];
AVAssetWriterInput *assetWriterInput = [AVAssetWriterInput assetWriterInputWithMediaType:AVMediaTypeVideo outputSettings:outputSettings];
/ AVCaptureVideDataOutput /
AVAssetWriterInputPixelBufferAdaptor *pixelBufferAdaptor =
[[AVAssetWriterInputPixelBufferAdaptor alloc]
initWithAssetWriterInput:assetWriterInput
sourcePixelBufferAttributes:
[NSDictionary dictionaryWithObjectsAndKeys:
[NSNumber numberWithInt:kCVPixelFormatType_32BGRA],
kCVPixelBufferPixelFormatTypeKey,
nil]];
/* Asset writer with MPEG4 format*/
AVAssetWriter *assetWriterMyData = [[AVAssetWriter alloc]
initWithURL:URLFromSomwhere
fileType:AVFileTypeMPEG4
error:you need to check error conditions,
this example is too lazy];
[assetWriterMyData addInput:assetWriterInput];
assetWriterInput.expectsMediaDataInRealTime = YES;
/ Start writing data /
[assetWriterMyData startWriting];
[assetWriterMyData startSessionAtSourceTime:kCMTimeZero];
[captureSession startRunning];
- (void) captureOutput:(AVCaptureOutput *)captureOutput
didOutputSampleBuffer:(CMSampleBufferRef)sampleBuffer
fromConnection:(AVCaptureConnection *)connection
{
CVImageBufferRef imageBuffer = CMSampleBufferGetImageBuffer(sampleBuffer);
// a very dense way to keep track of the time at which this frame
// occurs relative to the output stream, but it's just an example!
static int64_t frameNumber = 0;
if(assetWriterInput.readyForMoreMediaData)
[pixelBufferAdaptor appendPixelBuffer:imageBuffer
withPresentationTime:CMTimeMake(frameNumber, 25)];
frameNumber++;
}
/* To stop recording, stop capture session and finish writing data*/
[captureSession stopRunning];
[assetWriterMyData finishWriting];