前置摄像头视频录制 iPhone 4？

Posted 2023-02-23

【中文标题】前置摄像头视频录制 iPhone 4？

【英文标题】：Front Camera Video Recording iPhone 4?

【发布时间】：2010-10-27 06:49:07

【问题描述】：

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

【参考方案1】：

您正在丢弃错误 - 如果这样做，您将如何调试？

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……

【参考方案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。