问题
I am trying to record video in my iPhone app using AVFoundation. But whenever I click the Record button app crashes with this message
-[AVCaptureMovieFileOutput startRecordingToOutputFileURL:recordingDelegate:] - no active/enabled connections.
I know same question asked in SO, but none of its answers helped me. My problem is the same code works with another application perfectly, and when I try using exactly same code in this app - crashes. But still photo capture is working fine.
Adding my codes here - please help me, Thanks in advance
-(void)viewDidLoad
{
[super viewDidLoad];
self.captureSession = [[AVCaptureSession alloc] init];
AVCaptureDevice *videoDevice = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo];
AVCaptureDevice *audioDevice = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeAudio];
self.videoInput = [AVCaptureDeviceInput deviceInputWithDevice:videoDevice error:nil];
self.audioInput = [[AVCaptureDeviceInput alloc] initWithDevice:audioDevice error:nil];
self.stillImageOutput = [[AVCaptureStillImageOutput alloc] init];
NSDictionary *stillImageOutputSettings = [[NSDictionary alloc] initWithObjectsAndKeys:
AVVideoCodecJPEG, AVVideoCodecKey, nil];
[self.stillImageOutput setOutputSettings:stillImageOutputSettings];
self.movieOutput = [[AVCaptureMovieFileOutput alloc] init];
[self.captureSession addInput:self.videoInput];
[self.captureSession addOutput:self.stillImageOutput];
previewLayer = [AVCaptureVideoPreviewLayer layerWithSession:self.captureSession];
UIView *aView = self.view;
previewLayer.frame = CGRectMake(70, 190, 270, 270);
[aView.layer addSublayer:previewLayer];
}
-(NSURL *) tempFileURL
{
NSString *outputPath = [[NSString alloc] initWithFormat:@"%@%@", NSTemporaryDirectory(), @"output.mov"];
NSURL *outputURL = [[NSURL alloc] initFileURLWithPath:outputPath];
NSFileManager *manager = [[NSFileManager alloc] init];
if ([manager fileExistsAtPath:outputPath])
{
[manager removeItemAtPath:outputPath error:nil];
}
return outputURL;
}
-(IBAction)capture:(id)sender
{
if (self.movieOutput.isRecording == YES)
{
[self.movieOutput stopRecording];
}
else
{
[self.movieOutput startRecordingToOutputFileURL:[self tempFileURL] recordingDelegate:self];
}
}
-(void)captureOutput:(AVCaptureFileOutput *)captureOutput didFinishRecordingToOutputFileAtURL:(NSURL *)outputFileURL
fromConnections:(NSArray *)connections
error:(NSError *)error
{
BOOL recordedSuccessfully = YES;
if ([error code] != noErr)
{
id value = [[error userInfo] objectForKey:AVErrorRecordingSuccessfullyFinishedKey];
if (value)
recordedSuccessfully = [value boolValue];
NSLog(@"A problem occurred while recording: %@", error);
}
if (recordedSuccessfully) {
ALAssetsLibrary *library = [[ALAssetsLibrary alloc] init];
[library writeVideoAtPathToSavedPhotosAlbum:outputFileURL
completionBlock:^(NSURL *assetURL, NSError *error)
{
UIAlertView *alert;
if (!error)
{
alert = [[UIAlertView alloc] initWithTitle:@"Video Saved"
message:@"The movie was successfully saved to you photos library"
delegate:nil
cancelButtonTitle:@"OK"
otherButtonTitles:nil, nil];
}
else
{
alert = [[UIAlertView alloc] initWithTitle:@"Error Saving Video"
message:@"The movie was not saved to you photos library"
delegate:nil
cancelButtonTitle:@"OK"
otherButtonTitles:nil, nil];
}
[alert show];
}
];
}
}
回答1:
I had the same problem while changing videoDevice activeFormat and later wanted to record video. Because I was using best quality video I had to set sessionPreset to high, like following
_session.sessionPreset = AVCaptureSessionPresetHigh;
and it worked for me! :)
回答2:
Because currently you don't have an active connection to record video to file.
Check connection active status before recording to output file:
AVCaptureConnection *c = [self.movieOutput connectionWithMediaType:AVMediaTypeVideo];
if (c.active) {
//connection is active
} else {
//connection is not active
//try to change self.captureSession.sessionPreset,
//or change videoDevice.activeFormat
}
If connection is not active, try to change captureSession.sessionPreset or videoDevice.activeFormat.
Repeat until you have set a valid format (that means c.active == YES). Then you can record video to output file.
回答3:
Several things are missing in your code :
- You forgot to add
movieOutputto yourcaptureSession - Same for your
audioInput - All your session configuration needs to be encapsulated by
[_captureSession beginConfiguration]and[_captureSession commitConfiguration] - For audio recording you need to set the
AVAudioSessionto the correct category.
Here is your code updated :
- (void)viewDidLoad
{
[super viewDidLoad];
NSError *error = nil;
[[AVAudioSession sharedInstance] setCategory:AVAudioSessionCategoryRecord
error:&error];
if(!error)
{
[[AVAudioSession sharedInstance] setActive:YES error:&error];
if(error) NSLog(@"Error while activating AudioSession : %@", error);
}
else
{
NSLog(@"Error while setting category of AudioSession : %@", error);
}
self.captureSession = [[AVCaptureSession alloc] init];
AVCaptureDevice *videoDevice = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo];
AVCaptureDevice *audioDevice = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeAudio];
self.videoInput = [AVCaptureDeviceInput deviceInputWithDevice:videoDevice error:nil];
self.audioInput = [[AVCaptureDeviceInput alloc] initWithDevice:audioDevice error:nil];
self.stillImageOutput = [[AVCaptureStillImageOutput alloc] init];
NSDictionary *stillImageOutputSettings = [[NSDictionary alloc] initWithObjectsAndKeys:
AVVideoCodecJPEG, AVVideoCodecKey, nil];
[self.stillImageOutput setOutputSettings:stillImageOutputSettings];
self.movieOutput = [[AVCaptureMovieFileOutput alloc] init];
[self.captureSession beginConfiguration];
[self.captureSession addInput:self.videoInput];
[self.captureSession addInput:self.audioInput];
[self.captureSession addOutput:self.movieOutput];
[self.captureSession addOutput:self.stillImageOutput];
[self.captureSession commitConfiguration];
AVCaptureVideoPreviewLayer *previewLayer = [AVCaptureVideoPreviewLayer layerWithSession:self.captureSession];
previewLayer.frame = CGRectMake(0, 0, 320, 500);
[self.view.layer addSublayer:previewLayer];
[self.captureSession startRunning];
}
- (IBAction)toggleRecording:(id)sender
{
if(!self.movieOutput.isRecording)
{
[self.recordButton setTitle:@"Stop" forState:UIControlStateNormal];
NSString *outputPath = [NSTemporaryDirectory() stringByAppendingPathComponent:@"output.mp4"];
NSFileManager *manager = [[NSFileManager alloc] init];
if ([manager fileExistsAtPath:outputPath])
{
[manager removeItemAtPath:outputPath error:nil];
}
[self.movieOutput startRecordingToOutputFileURL:[NSURL fileURLWithPath:outputPath]
recordingDelegate:self];
}
else
{
[self.recordButton setTitle:@"Start recording" forState:UIControlStateNormal];
[self.movieOutput stopRecording];
}
}
- (void)captureOutput:(AVCaptureFileOutput *)captureOutput didFinishRecordingToOutputFileAtURL:(NSURL *)outputFileURL fromConnections:(NSArray *)connections error:(NSError *)error
{
NSLog(@"Did finish recording, error %@ | path %@ | connections %@", error, [outputFileURL absoluteString], connections);
}
Hope this helps
回答4:
I find the reason of this error. check your session's "setSessionPreset" setting, photo's resolution setting is different from video, for iPhone5, video resolution of the back camera is 1920*1080, the front camere is 1280*720, and photo's max resolution is 3264*2488, so if you set error resolution to video, the connect will not be actived.
来源：https://stackoverflow.com/questions/22110911/avcapturemoviefileoutput-no-active-enabled-connections