前置摄像头视频录制 iPhone 4？

Question

我正在尝试借助我从 iPhone 开发人员程序获得的 WWDC 示例，使用 AVFoundation 框架从 iPhone 4 的前置摄像头录制视频。但我仍然无法让它工作......视频没有被录制或可能保存在我的 iPhone 库中......这是我正在尝试使用的代码......如果有人能帮助我解决这个问题，那将非常有帮助我有吗？？

-(void)recordVideo
{

AVCaptureDeviceInput *videoInput = [[AVCaptureDeviceInput alloc] initWithDevice:[self backFacingCamera] error:nil];

AVCaptureMovieFileOutput *movieFileOutput = [[AVCaptureMovieFileOutput alloc] init];

AVCaptureSession *session = [[AVCaptureSession alloc] init];

[session addInput:videoInput];

[session addOutput:movieFileOutput];

[movieFileOutput release];  


if (![session isRunning])
 {
 [self performSelector:@selector(startRecording) withObject:nil afterDelay:1.0];
 [session startRunning];

 }

}

- (void) startRecording
{
    NSLog(@"start recording");


AVCaptureConnection *videoConnection = [playVideo connectionWithMediaType:AVMediaTypeVideo fromConnections:[[self movieFileOutput] connections]];
if ([videoConnection isVideoOrientationSupported]) {
    [videoConnection setVideoOrientation:[self orientation]]; 
}

[[self movieFileOutput] startRecordingToOutputFileURL:[self tempFileURL]
                                    recordingDelegate:self];
}
- (void) stopRecording
{
    NSLog(@"stop recording");

    [[self movieFileOutput] stopRecording];
}
- (NSURL *) tempFileURL
{
    NSLog(@"temp file url");
    NSString *outputPath = [[NSString alloc] initWithFormat:@"%@%@", NSTemporaryDirectory(), @"output.mov"];
    NSURL *outputURL = [[NSURL alloc] initFileURLWithPath:outputPath];
    NSFileManager *fileManager = [NSFileManager defaultManager];
    if ([fileManager fileExistsAtPath:outputPath]) {
    NSLog(@"exists");
    }
    [outputPath release];
    return [outputURL autorelease];
}
- (void) setConnectionWithMediaType:(NSString *)mediaType enabled:(BOOL)enabled;
{

    [[playVideo connectionWithMediaType:AVMediaTypeVideo fromConnections:[[self movieFileOutput] connections]] setEnabled:enabled];
}

+ (AVCaptureConnection *)connectionWithMediaType:(NSString *)mediaType fromConnections:(NSArray *)connections;
{
    NSLog(@"connection with media type");
    for ( AVCaptureConnection *connection in connections ) {
        for ( AVCaptureInputPort *port in [connection inputPorts] ) {
            if ( [[port mediaType] isEqual:mediaType] ) {
                return [[connection retain] autorelease];
            }
        }
    }
    return nil;
}
@implementation recordVideo (Internal)

- (AVCaptureDevice *) cameraWithPosition:(AVCaptureDevicePosition) position
{
    NSArray *devices = [AVCaptureDevice devicesWithMediaType:AVMediaTypeVideo];
    for (AVCaptureDevice *device in devices) {
        if ([device position] == position) {
            return device;
        }
    }
    return nil;
}
- (AVCaptureDevice *) backFacingCamera
{
    NSLog(@"back");
    return [self cameraWithPosition:AVCaptureDevicePositionBack];
}
- (AVCaptureDevice *) frontFacingCamera
{
    NSLog(@"front ");
    return [self cameraWithPosition:AVCaptureDevicePositionFront];
}

@end
@implementation recordVideo (AVCaptureFileOutputRecordingDelegate)

- (void)             captureOutput:(AVCaptureFileOutput *)captureOutput
didStartRecordingToOutputFileAtURL:(NSURL *)fileURL
                   fromConnections:(NSArray *)connections
{
    NSLog(@"did start recording");

}

- (void)              captureOutput:(AVCaptureFileOutput *)captureOutput
didFinishRecordingToOutputFileAtURL:(NSURL *)outputFileURL
                    fromConnections:(NSArray *)connections
                              error:(NSError *)error
{
    NSLog(@"did finish recording output file");


    ALAssetsLibrary *library = [[ALAssetsLibrary alloc] init];

    if ([library videoAtPathIsCompatibleWithSavedPhotosAlbum:outputFileURL])
    {
        [library writeVideoAtPathToSavedPhotosAlbum:outputFileURL
                                    completionBlock:^(NSURL *assetURL, NSError *error){
                                        if (error && [delegate respondsToSelector:@selector(assetLibraryError:forURL:)]) {
                                            [delegate assetLibraryError:error forURL:assetURL];
                                        }
                                    }];
    } 
    else {

        }

    [library release];    


}
@end

Answer 1

1. 您正在丢弃错误 - 如果这样做，您将如何调试？

2. 您需要更具体地了解正在发生/未发生的事情。调用了哪些方法？ SDK 报告了哪些错误（如果有）？等等……

Answer 2

您已在 -(void)recordVideo 中发布了对 movieFileOutput 的引用； 并且您仍在 - (void) startRecording 中使用已发布的 movieFileOutput 以及 其他功能。你最好不要释放你正在使用的对象。