I am occasionally getting an NSInvalidArgumentException exception when I start recording video in a viewController but only after taking photos in a previous view controller. I've tried a couple suggestions from Google and So but still get this error at the startRecordingToOutputFileURL:fileURL call.
I never get the error if I don't visit the other view controller that takes photos - it only occurs when I take photos, and then switch to the new view controller which does the video recording.
I think there is some cruft left behind from taking photos, but when I initialize my Video recorder view controller I get no errors setting up the sessions and whatnot. Any ideas what is going on or how to recover from this? Why is it an NSInvalidArgumentException exception? Thanks!
Here is my code:
dispatch_async(dispatch_get_main_queue(), ^{
// Try to Fix bug:
// http://stackoverflow.com/questions/5979962/error-while-recording-video-on-iphone-using-avfoundation
[self.captureSession beginConfiguration];
// Ensure session is running
if ( [self.captureSession isRunning] == NO ) {
NSLog(#"Capture session is NOT running... Starting it now!");
[self.captureSession startRunning];
}
else {
NSLog(#"Capture session is ALREADY running...");
}
NSLog(#"File URL is: %#",fileURL);
NSLog(#"FileOutput is: %#",self.fileOutput);
[self.fileOutput startRecordingToOutputFileURL:fileURL recordingDelegate:self];
// Try to Fix bug:
// http://stackoverflow.com/questions/5979962/error-while-recording-video-on-iphone-using-avfoundation
[self.captureSession commitConfiguration];
});
Here is the error traceback:
2014-05-18 16:01:38.818 app[1699:60b] *** Start recording
2014-05-18 16:01:38.820 app[1699:60b] Capture session is ALREADY running...
2014-05-18 16:01:38.827 app[1699:60b] Capture session is ALREADY running...
2014-05-18 16:01:38.828 app[1699:60b] File URL is: file:////var/mobile/Applications/73FFC590-05A8-4D74-82D9-EBA122B00A20/Documents/2014-05-18-16-01-38-0.mp4
2014-05-18 16:01:38.828 app[1699:60b] FileOutput is: <AVCaptureMovieFileOutput: 0x16513b10>
2014-05-18 16:01:38.829 app[1699:60b] *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '*** -[AVCaptureMovieFileOutput startRecordingToOutputFileURL:recordingDelegate:] - no active/enabled connections.'
*** First throw call stack:
(0x2fe5ff0b 0x3a5f6ce7 0x2ed5751d 0xfb4b5 0x3aadfd53 0x3aadfd3f 0x3aae26c3 0x2fe2a681 0x2fe28f4d 0x2fd93769 0x2fd9354b 0x34d006d3 0x326f2891 0xe40c9 0x3aaf4ab7)
libc++abi.dylib: terminating with uncaught exception of type NSException
This is how the captureSession is initialized ( from the OpenSource project here: https://github.com/shu223/SlowMotionVideoRecorder ):
- (id)initWithPreviewView:(UIView *)previewView {
self = [super init];
if (self) {
NSError *error;
self.captureSession = [[AVCaptureSession alloc] init];
self.captureSession.sessionPreset = AVCaptureSessionPresetInputPriority;
AVCaptureDevice *videoDevice = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo];
AVCaptureDeviceInput *videoIn = [AVCaptureDeviceInput deviceInputWithDevice:videoDevice error:&error];
if (error) {
NSLog(#"Video input creation failed");
return nil;
}
if (![self.captureSession canAddInput:videoIn]) {
NSLog(#"Video input add-to-session failed");
return nil;
}
[self.captureSession addInput:videoIn];
// save the default format
self.defaultFormat = videoDevice.activeFormat;
defaultVideoMaxFrameDuration = videoDevice.activeVideoMaxFrameDuration;
AVCaptureDevice *audioDevice= [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeAudio];
AVCaptureDeviceInput *audioIn = [AVCaptureDeviceInput deviceInputWithDevice:audioDevice error:&error];
[self.captureSession addInput:audioIn];
self.fileOutput = [[AVCaptureMovieFileOutput alloc] init];
[self.captureSession addOutput:self.fileOutput];
self.previewLayer = [[AVCaptureVideoPreviewLayer alloc] initWithSession:self.captureSession];
self.previewLayer.frame = previewView.bounds;
self.previewLayer.contentsGravity = kCAGravityResizeAspectFill;
self.previewLayer.videoGravity = AVLayerVideoGravityResizeAspectFill;
[previewView.layer insertSublayer:self.previewLayer atIndex:0];
[self.captureSession startRunning];
}
return self;
}
My code utilizes this initialization code like this in viewDidLoad:
self.captureManager = [[AVCaptureManager alloc] initWithPreviewView:self.view];
self.captureManager.delegate = self;
The code that actually starts and stops recording is done from an IBAction method like this:
- (IBAction)recButtonTapped:(id)sender {
// REC START
if (self.captureManager.isRecording == NO ) {
NSLog(#"*** Start recording");
// change UI
[self.recBtn setImage:self.recStopImage
forState:UIControlStateNormal];
self.fpsControl.enabled = NO;
// timer start
startTime = [[NSDate date] timeIntervalSince1970];
self.timer = [NSTimer scheduledTimerWithTimeInterval:0.01
target:self
selector:#selector(timerHandler:)
userInfo:nil
repeats:YES];
[self.captureManager startRecording];
}
// REC STOP
else {
NSLog(#"*** Stop recording");
isNeededToSave = YES;
[self.captureManager stopRecording];
[self.timer invalidate];
self.timer = nil;
// change UI
[self.recBtn setImage:self.recStartImage
forState:UIControlStateNormal];
self.fpsControl.enabled = YES;
}
}
EDIT - I am definitely closing the session in the Photo view, here is that code. I verified that it is being called when I leave the Photo view controller.
NSLog(#"RELEASE PHOTO SESSION NOW!");
for(AVCaptureInput *input1 in _mySesh.inputs) {
[_mySesh removeInput:input1];
}
for(AVCaptureOutput *output1 in _mySesh.outputs) {
[_mySesh removeOutput:output1];
}
[_mySesh stopRunning];
// Fix closing of session
dispatch_after(
dispatch_time(0,500000000),
dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0),
^{
_mySesh = nil;
}
);
UPDATE #####
According to the only answer below, I tried to 'unlink' the file prior to starting recording. It still did not work.
NSURL *fileURL = [NSURL URLWithString:[#"file://" stringByAppendingString:filePath]];
//NSLog(#"Beginning to record to output file...");
dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_BACKGROUND, 0), ^{
// Wait for session to start
//[NSThread sleepForTimeInterval:1.0];
dispatch_async(dispatch_get_main_queue(), ^{
// Ensure session is running
if ( [self.captureSession isRunning] == NO ) {
NSLog(#"Capture session is NOT running... Starting it now!");
[self.captureSession startRunning];
}
else {
NSLog(#"Capture session is ALREADY running...");
}
NSLog(#"File URL is: %#",fileURL);
NSLog(#"FileOutput is: %#",self.fileOutput);
// Delete the file
unlink([[#"file://" stringByAppendingString:filePath] UTF8String]);
[self.fileOutput startRecordingToOutputFileURL:fileURL recordingDelegate:self];
});
});
UPDATE
Just for posterity, I am calling the 'didFinishRecordingToOutputFileAtURL' delegate method:
- (void) captureOutput:(AVCaptureFileOutput *)captureOutput
didFinishRecordingToOutputFileAtURL:(NSURL *)outputFileURL
fromConnections:(NSArray *)connections error:(NSError *)error
{
// Print any errors
if ( error ) {
NSLog(#"Error Recording Video! %#",error.localizedDescription);
}
_isRecording = NO;
if ([self.delegate respondsToSelector:#selector(didFinishRecordingToOutputFileAtURL:error:)]) {
[self.delegate didFinishRecordingToOutputFileAtURL:outputFileURL error:error];
}
}
First of all, start AVCaptureSession first. After that you can create AVPreviewLayer and AVCaptureMovieFileOutput.
Second, use -[AVCaptureSession canAddOutput:] and -[AVCaptureSession canAddInput:] before adding anything to the capture session, this will save you a lot of time and frustration.
Third, you only need beginConfiguration and commitConfiguration when you want to change lots of things in captureSession at once, e.g. remove input, change preset. It's useful on front/back camera switch if you're going to implement it. Starting or stopping session in between these calls is no bueno.
From what I see this is due to the file already existing.
Try removing the file before your call to startRecordingToOutputFileURL: with:
[[NSFileManager defaultManager] removeItemAtPath:fileURL];
You can double check with:
[[NSFileManager defaultManager] fileExistsAtPath:fileURL];
If a file at the given URL already exists when capturing starts, recording to the new file will fail.
Another thing that might cause the crash is if you don't have the delegate method implemented.
It is required to implement:
captureOutput:didFinishRecordingToOutputFileAtURL:fromConnections:error:
because that is the only reliable place to get the output.
Another suspicious thing:
When you create fileURL, you do
NSURL *fileURL = [NSURL URLWithString:[#"file://" stringByAppendingString:filePath]];
Can you change that to
NSURL *fileURL = [NSURL fileURLWithPath:filePath];
And make sure filePath is valid.
From the documentation: This method throws an NSInvalidArgumentException if the URL is not a valid file URL.
Try to comment self.captureSession.sessionPreset = ... line and see if it helps. It made the trick for me. The reason of the problem was that I tried to capture photos with highest quality and FOV, but with this setting I was getting "no active/enabled connections" exception when I tried to capture a video.
Just make sessionPreset high.
swift 4
self.captureSession.sessionPreset = .high
Related
I am writing a program that reads a QR code and then uses the data collected. I am having a strange problem though. I believe it may have to do something with threads. Basically all the NSLogs in the if statement work fine and print rapidly every second yet when i try to update a label text or change the background color it takes ~40 seconds. I don't understand why. Here is the code.
#import "VerifyPassViewController.h"
#import "NewPassViewController.h"
#interface VerifyPassViewController ()
-(BOOL)startReading;
-(void)stopReading;
-(void)loadBeepSound;
#end
#implementation VerifyPassViewController
- (void)viewDidLoad
{
[super viewDidLoad];
// Do any additional setup after loading the view, typically from a nib.
// Initially make the captureSession object nil.
_captureSession = nil;
// Set the initial value of the flag to NO.
_isReading = NO;
}
- (void)didReceiveMemoryWarning
{
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
}
#pragma mark - IBAction method implementation
- (IBAction)startStopReading:(id)sender {
if (!_isReading) {
// This is the case where the app should read a QR code when the start button is tapped.
if ([self startReading]) {
// If the startReading methods returns YES and the capture session is successfully
// running, then change the start button title and the status message.
[_bbITem setTitle:#"Stop"];
[_bbITem setTitle:#"Scanning for QR Code..."];
}
}
else{
// In this case the app is currently reading a QR code and it should stop doing so.
[self stopReading];
// The bar button item's title should change again.
[_bbITem setTitle:#"Start!"];
}
// Set to the flag the exact opposite value of the one that currently has.
_isReading = !_isReading;
}
#pragma mark - Private method implementation
- (BOOL)startReading {
NSError *error;
// Get an instance of the AVCaptureDevice class to initialize a device object and provide the video
// as the media type parameter.
AVCaptureDevice *captureDevice = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo];
// Get an instance of the AVCaptureDeviceInput class using the previous device object.
AVCaptureDeviceInput *input = [AVCaptureDeviceInput deviceInputWithDevice:captureDevice error:&error];
if (!input) {
// If any error occurs, simply log the description of it and don't continue any more.
NSLog(#"%#", [error localizedDescription]);
return NO;
}
// Initialize the captureSession object.
_captureSession = [[AVCaptureSession alloc] init];
// Set the input device on the capture session.
[_captureSession addInput:input];
// Initialize a AVCaptureMetadataOutput object and set it as the output device to the capture session.
AVCaptureMetadataOutput *captureMetadataOutput = [[AVCaptureMetadataOutput alloc] init];
[_captureSession addOutput:captureMetadataOutput];
// Create a new serial dispatch queue.
dispatch_queue_t dispatchQueue;
dispatchQueue = dispatch_queue_create("myQueue", NULL);
[captureMetadataOutput setMetadataObjectsDelegate:self queue:dispatchQueue];
[captureMetadataOutput setMetadataObjectTypes:[NSArray arrayWithObject:AVMetadataObjectTypeQRCode]];
// Initialize the video preview layer and add it as a sublayer to the viewPreview view's layer.
_videoPreviewLayer = [[AVCaptureVideoPreviewLayer alloc] initWithSession:_captureSession];
[_videoPreviewLayer setVideoGravity:AVLayerVideoGravityResizeAspectFill];
[_videoPreviewLayer setFrame:_viewPreview.layer.bounds];
[_viewPreview.layer addSublayer:_videoPreviewLayer];
// Start video capture.
[_captureSession startRunning];
return YES;
}
-(void)stopReading{
// Stop video capture and make the capture session object nil.
[_captureSession stopRunning];
_captureSession = nil;
// Remove the video preview layer from the viewPreview view's layer.
[_videoPreviewLayer removeFromSuperlayer];
}
#pragma mark - AVCaptureMetadataOutputObjectsDelegate method implementation
- (void)captureOutput:(AVCaptureOutput *)captureOutput didOutputMetadataObjects:(NSArray *)metadataObjects fromConnection:(AVCaptureConnection *)connection
{
for(AVMetadataObject *metadataObject in metadataObjects)
{
AVMetadataMachineReadableCodeObject *readableObject = (AVMetadataMachineReadableCodeObject *)metadataObject;
if([metadataObject.type isEqualToString:AVMetadataObjectTypeQRCode])
{
NSLog(#"QR Code = %#", readableObject.stringValue);
self.view.backgroundColor = [UIColor greenColor];
NSLog(#"If the background isnt green i might throw up");
}
else if ([metadataObject.type isEqualToString:AVMetadataObjectTypeEAN13Code])
{
NSLog(#"EAN 13 = %#", readableObject.stringValue);
}
}
}
#end
Let me know if you have any ideas. Thank you
You can only update the UI from the main thread:
dispatch_async(dispatch_get_main_queue(), ^{
... update here your ui ..
});
To state clearly what the other posters hint at: Your code is setting up a dispatch queue that runs on a background thread to process any QR codes it recognizes.
Your captureOutput:didOutputMetadataObjects:fromConnection: method will be run on a background thread.
UI code must be performed on the main thread. rafaperez posted code that you can use from a background thread to dispatch UI changes to a queue on the main thread.
You could also use the method performSelectorOnMainThread:withObject:waitUntilDone: in order to send single method calls to the main thread.
i had to convert big file size song from iTunes library to a smaller 8K song file.
As i did the converting async, the bool always return true even though writing to doc folder are not completed. At the moment i'm using a delay of 10sec before i called the function again and it works fine on the interim for iPhone 5s, but i would like to cater on the slower devices.
kindly give me some pointer / recommendation on my code.
-(void)startUploadSongAnalysis
{
[self updateProgressYForID3NForUpload:NO];
if ([self.uploadWorkingAray count]>=1)
{
Song *songVar = [self.uploadWorkingAray objectAtIndex:0];//core data var
NSLog(#"songVar %#",songVar.songName);
NSLog(#"songVar %#",songVar.songURL);
NSURL *songU = [NSURL URLWithString:songVar.songURL]; //URL of iTunes Lib
// self.asset = [AVAsset assetWithURL:songU];
// NSLog(#"asset %#",self.asset);
NSError *error;
NSString *subString = [[songVar.songURL componentsSeparatedByString:#"id="] lastObject];
NSString *savedPath = [self.documentsDir stringByAppendingPathComponent:[NSString stringWithFormat:#"audio%#.m4a",subString]];//save file name of converted 8kb song
NSString *subStringPath = [NSString stringWithFormat:#"audio%#.m4a",subString];
if ([self.fileManager fileExistsAtPath:savedPath] == YES)
[self.fileManager removeItemAtPath:savedPath error:&error];
NSLog(#"cacheDir %#",savedPath);
//export low bitrate song to cache
if ([self exportAudio:[AVAsset assetWithURL:songU] toFilePath:savedPath]) // HERE IS THE PROBLEM, this return true even the writing is not completed cos when i upload to my web server, it will say song file corrupted
{
// [self performSelector:#selector(sendSongForUpload:) withObject:subStringPath afterDelay:1];
[self sendRequest:2 andPath:subStringPath andSongDBItem:songVar];
}
else
{
NSLog(#"song too short, skipped");
[self.uploadWorkingAray removeObjectAtIndex:0];
[self.songNotFoundArray addObject:songVar];
[self startUploadSongAnalysis];
}
}
else //uploadWorkingAray empty
{
NSLog(#"save changes");
[[VPPCoreData sharedInstance] saveAllChanges];
}
}
#pragma mark song exporter to doc folder
- (BOOL)exportAudio:(AVAsset *)avAsset toFilePath:(NSString *)filePath
{
CMTime assetTime = [avAsset duration];
Float64 duration = CMTimeGetSeconds(assetTime);
if (duration < 40.0) return NO; // if song too short return no
// get the first audio track
NSArray *tracks = [avAsset tracksWithMediaType:AVMediaTypeAudio];
if ([tracks count] == 0) return NO;
NSError *readerError = nil;
AVAssetReader *reader = [[AVAssetReader alloc] initWithAsset:avAsset error:&readerError];
//AVAssetReader *reader = [AVAssetReader assetReaderWithAsset:avAsset error:&readerError]; // both works the same ?
AVAssetReaderOutput *readerOutput = [AVAssetReaderAudioMixOutput
assetReaderAudioMixOutputWithAudioTracks:avAsset.tracks
audioSettings: nil];
if (! [reader canAddOutput: readerOutput])
{
NSLog (#"can't add reader output...!");
return NO;
}
else
{
[reader addOutput:readerOutput];
}
// writer AVFileTypeCoreAudioFormat AVFileTypeAppleM4A
NSError *writerError = nil;
AVAssetWriter *writer = [[AVAssetWriter alloc] initWithURL:[NSURL fileURLWithPath:filePath]
fileType:AVFileTypeAppleM4A
error:&writerError];
//NSLog(#"writer %#",writer);
AudioChannelLayout channelLayout;
memset(&channelLayout, 0, sizeof(AudioChannelLayout));
channelLayout.mChannelLayoutTag = kAudioChannelLayoutTag_Stereo;
// use different values to affect the downsampling/compression
// NSDictionary *outputSettings = [NSDictionary dictionaryWithObjectsAndKeys:
// [NSNumber numberWithInt: kAudioFormatMPEG4AAC], AVFormatIDKey,
// [NSNumber numberWithFloat:16000.0], AVSampleRateKey,
// [NSNumber numberWithInt:2], AVNumberOfChannelsKey,
// [NSNumber numberWithInt:128000], AVEncoderBitRateKey,
// [NSData dataWithBytes:&channelLayout length:sizeof(AudioChannelLayout)], AVChannelLayoutKey,
// nil];
NSDictionary *outputSettings = #{AVFormatIDKey: #(kAudioFormatMPEG4AAC),
AVEncoderBitRateKey: #(8000),
AVNumberOfChannelsKey: #(1),
AVSampleRateKey: #(8000)};
AVAssetWriterInput *writerInput = [[AVAssetWriterInput alloc] initWithMediaType:AVMediaTypeAudio outputSettings:outputSettings];
//\Add inputs to Write
NSParameterAssert(writerInput);
NSAssert([writer canAddInput:writerInput], #"Cannot write to this type of audio input" );
if ([writer canAddInput:writerInput])
{
[writer addInput:writerInput];
}
else
{
NSLog (#"can't add asset writer input... die!");
return NO;
}
[writerInput setExpectsMediaDataInRealTime:NO];
[writer startWriting];
[writer startSessionAtSourceTime:kCMTimeZero];
[reader startReading];
__block UInt64 convertedByteCount = 0;
__block BOOL returnValue;
__block CMSampleBufferRef nextBuffer;
dispatch_queue_t mediaInputQueue = dispatch_queue_create("mediaInputQueue", NULL);
[writerInput requestMediaDataWhenReadyOnQueue:mediaInputQueue usingBlock:^{
// NSLog(#"Asset Writer ready : %d", writerInput.readyForMoreMediaData);
while (writerInput.readyForMoreMediaData)
{
nextBuffer = [readerOutput copyNextSampleBuffer];
if (nextBuffer)
{
[writerInput appendSampleBuffer: nextBuffer];
convertedByteCount += CMSampleBufferGetTotalSampleSize (nextBuffer);
//NSNumber *convertedByteCountNumber = [NSNumber numberWithLong:convertedByteCount];
//NSLog (#"writing");
CFRelease(nextBuffer);
}
else
{
[writerInput markAsFinished];
[writer finishWritingWithCompletionHandler:^{
if (AVAssetWriterStatusCompleted == writer.status)
{
NSLog(#"Writer completed");
returnValue = YES; //I NEED TO RETURN SOMETHING FROM HERE AFTER WRITING COMPLETED
dispatch_async(mediaInputQueue, ^{
dispatch_async(dispatch_get_main_queue(), ^{
// add this to the main queue as the last item in my serial queue
// when I get to this point I know everything in my queue has been run
NSDictionary *outputFileAttributes = [[NSFileManager defaultManager]
attributesOfItemAtPath:filePath
error:nil];
NSLog (#"done. file size is %lld",
[outputFileAttributes fileSize]);
});
});
}
else if (AVAssetWriterStatusFailed == writer.status)
{
[writer cancelWriting];
[reader cancelReading];
NSLog(#"Writer failed");
return;
}
else
{
NSLog(#"Export Session Status: %d", writer.status);
}
}];
break;
}
}
}];
tracks = nil;
writer = nil;
writerInput = nil;
reader = nil;
readerOutput=nil;
mediaInputQueue = nil;
return returnValue;
//return YES;
}
Your method exportAudio:toFilePath: is actually an asynchronous method and requires a few fixes to become a proper asynchronous method.
First, you should provide a completion handler in order to signal the call-site that the underlying task has been finished:
- (void)exportAudio:(AVAsset *)avAsset
toFilePath:(NSString *)filePath
completion:(completion_t)completionHandler;
Note, that the result of the method is passed through the completion handler, whose signature might be as follows:
typedef void (^completion_t)(id result);
where parameter result is the eventual result of the method. You should always return an NSError object when anything goes wrong when setting up the various objects within the method - even though, the method could return an immediate result indicating an error.
Next, if you take a look into to documentation you can read:
requestMediaDataWhenReadyOnQueue:usingBlock:
- (void)requestMediaDataWhenReadyOnQueue:(dispatch_queue_t)queue
usingBlock:(void (^)(void))block
Discussion
The block should append media data to the input either until the input’s readyForMoreMediaData property becomes NO or until there is no more media data to supply (at which point it may choose to mark the input as finished using markAsFinished). The block should then exit. After the block exits, if the input has not been marked as finished, once the input has processed the media data it has received and becomes ready for more media data again, it will invoke the block again in order to obtain more.
You should now be quite sure when your task is actually finished. You determine this within the block which is passed to the method requestMediaDataWhenReadyOnQueue:usingBlock:.
When the task is finished you call the completion handler completionHandler provided in
method exportAudio:toFilePath:completion:.
Of course, you need to fix your implementation, e.g. having the method ending with
tracks = nil;
writer = nil;
writerInput = nil;
reader = nil;
readerOutput=nil;
mediaInputQueue = nil;
return returnValue;
//return YES;
}
makes certainly no sense. Cleaning up and returning a result shall be done when the asynchronous task is actually finished. Unless an error occurs during setup, you need to determine this in the block passed to the method requestMediaDataWhenReadyOnQueue:usingBlock:.
In any case, in order to signal the result to the call-site call the completion handler completionHandler and pass a result object, e.g. if it succeeded the URL where it has been saved, otherwise an NSError object.
Now, since our method startUploadSongAnalysis is calling an asynchronous method, this method inevitable becomes asynchronous as well!
If I understood your original code correctly, you are invoking it recursively in order to process a number of assets. In order to implement this correctly, you need a few fixes shown below. The resulting "construct" is NOT a recursive method though, but instead an iteratively invocation of an asynchronous method ("asynchronous loop").
You may or may not provide a completion handler - same as above. It's up to you - but I would recommend it, it won't hurt to know when all assets have been processed. It may look as follows:
-(void)startUploadSongAnalysisWithCompletion:(completion_t)completionHandler
{
[self updateProgressYForID3NForUpload:NO];
// *** check for break condition: ***
if ([self.uploadWorkingAray count]>=1)
{
... stuff
//export low bitrate song to cache
[self exportAudio:[AVAsset assetWithURL:songU]
toFilePath:savedPath
completion:^(id urlOrError)
{
if ([urlOrError isKindOfClass[NSError class]]) {
// Error occurred:
NSLog(#"Error: %#", urlOrError);
// There are two alternatives to proceed:
// A) Ignore or remember the error and proceed with the next asset.
// In this case, it would be best to have a result array
// containing all the results. Then, invoke
// startUploadSongAnalysisWithCompletion: in order to proceed
// with the next asset.
//
// B) Stop with error.
// Don't call startUploadSongAnalysisWithCompletion: but
// instead invoke the completion handler passing it the error.
// A:
// possibly dispatch to a sync queue or the main thread!
[self.uploadWorkingAray removeObjectAtIndex:0];
[self.songNotFoundArray addObject:songVar];
// *** next song: ***
[self startUploadSongAnalysisWithCompletion:completionHandler];
}
else {
// Success:
// *** next song: ***
NSURL* url = urlOrError;
[self startUploadSongAnalysisWithCompletion:completionHandler];
}
}];
}
else //uploadWorkingAray empty
{
NSLog(#"save changes");
[[VPPCoreData sharedInstance] saveAllChanges];
// *** signal completion ***
if (completionHandler) {
completionHandler(#"OK");
}
}
}
I am not sure, but can not you send a call to a method like following
dispatch_async(mediaInputQueue, ^{
dispatch_async(dispatch_get_main_queue(), ^{
// add this to the main queue as the last item in my serial queue
// when I get to this point I know everything in my queue has been run
NSDictionary *outputFileAttributes = [[NSFileManager defaultManager]
attributesOfItemAtPath:filePath
error:nil];
NSLog (#"done. file size is %lld",
[outputFileAttributes fileSize]);
//calling the following method after completing the queue
[self printMe];
});
});
-(void)printMe{
NSLog(#"queue complete...");
//Do the next job, may be the following task !!!
if ([self exportAudio:[AVAsset assetWithURL:songU] toFilePath:savedPath]) // HERE IS THE PROBLEM, this return true even the writing is not completed cos when i upload to my web server, it will say song file corrupted
{
// [self performSelector:#selector(sendSongForUpload:) withObject:subStringPath afterDelay:1];
[self sendRequest:2 andPath:subStringPath andSongDBItem:songVar];
}
else
{
NSLog(#"song too short, skipped");
[self.uploadWorkingAray removeObjectAtIndex:0];
[self.songNotFoundArray addObject:songVar];
[self startUploadSongAnalysis];
}
}
I have a fairly lengthy method for a stop motion app that is slightly different for each of the various options pressed, timers, self timers, etc
Can define the main body of the method:
// initiate a still image capture, return immediately
// the completionHandler is called when a sample buffer has been captured
AVCaptureConnection *stillImageConnection = [stillImageOutput connectionWithMediaType:AVMediaTypeVideo];
[stillImageOutput captureStillImageAsynchronouslyFromConnection:stillImageConnection
completionHandler:^(CMSampleBufferRef imageDataSampleBuffer, NSError *__strong error) {
// set up the AVAssetWriter using the format description from the first sample buffer captured
if ( !assetWriter ) {
outputURL = [NSURL fileURLWithPath:[NSString stringWithFormat:#"%#/%llu.mov", NSTemporaryDirectory(), mach_absolute_time()]];
//NSLog(#"Writing movie to \"%#\"", outputURL);
CMFormatDescriptionRef formatDescription = CMSampleBufferGetFormatDescription(imageDataSampleBuffer);
if ( NO == [self setupAssetWriterForURL:outputURL formatDescription:formatDescription] )
return;
}
// re-time the sample buffer - in this sample frameDuration is set to 5 fps
CMSampleTimingInfo timingInfo = kCMTimingInfoInvalid;
timingInfo.duration = frameDuration;
timingInfo.presentationTimeStamp = nextPTS;
CMSampleBufferRef sbufWithNewTiming = NULL;
OSStatus err = CMSampleBufferCreateCopyWithNewTiming(kCFAllocatorDefault,
imageDataSampleBuffer,
1, // numSampleTimingEntries
&timingInfo,
&sbufWithNewTiming);
if (err)
return;
// append the sample buffer if we can and increment presnetation time
if ( [assetWriterInput isReadyForMoreMediaData] ) {
if ([assetWriterInput appendSampleBuffer:sbufWithNewTiming]) {
nextPTS = CMTimeAdd(frameDuration, nextPTS);
}
else {
NSError *error = [assetWriter error];
NSLog(#"failed to append sbuf: %#", error);
}
}
// release the copy of the sample buffer we made
CFRelease(sbufWithNewTiming);
}];
and just make variations of the method with the timers etc
First I tried making a singleton but although I got the method called I had other issues with the saving and writing to file. Can I make a MACRO out of a method?
I researched on SO here iOS create macro
Am I on the right track? can i define a method rather than image as in that example
Making a macro out of a method, while possible, is a terrible idea for a variety of reasons.
Why not just make it a class method? You won't have to worry about management of a class instance, and it won't muddy up the global namespace.
I'm going insane trying to get an AVCaptureSession (in a view controller) to be presented and dismissed in my project. I'm currently on iOS5.1 and have ARC enabled.
I can get it to work fine the first time I present the viewcontroller and start the session but when I dismiss and present a second time the session will not start. I subscribed to the "AVCaptureSessionRuntimeErrorNotification" notification and receive the following error:
"Error Domain=AVFoundationErrorDomain Code=-11819 "Cannot Complete Action" UserInfo=0x1a4020 {NSLocalizedRecoverySuggestion=Try again later., NSLocalizedDescription=Cannot Complete Action}"
I'm assuming that something is not being properly released in my session, but with ARC there are no releases and I instead set everything to be released to nil.
my viewDidLoad methods basically just triggers initCamera
initCamera method:
AVCaptureSession *tmpSession = [[AVCaptureSession alloc] init];
session = tmpSession;
session.sessionPreset = AVCaptureSessionPresetMedium;
captureVideoPreviewLayer = [[AVCaptureVideoPreviewLayer alloc] initWithSession:session];
captureVideoPreviewLayer.frame = self.vImagePreview.bounds;
[self.vImagePreview.layer addSublayer:captureVideoPreviewLayer];
rearCamera = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo];
NSError *error = nil;
input = [AVCaptureDeviceInput deviceInputWithDevice:rearCamera error:&error];
if (!input) {
// Handle the error appropriately.
NSLog(#"ERROR: trying to open camera: %#", error);
}
[session addInput:input];
videoDataOutput = [[AVCaptureVideoDataOutput alloc] init];
NSDictionary *outputSettings = [[NSDictionary alloc] initWithObjectsAndKeys: [NSNumber numberWithInt:kCVPixelFormatType_32BGRA], kCVPixelBufferPixelFormatTypeKey, nil];
[videoDataOutput setVideoSettings:outputSettings];
[videoDataOutput setAlwaysDiscardsLateVideoFrames:YES];
queue = dispatch_queue_create("cameraQueue", DISPATCH_QUEUE_SERIAL);
[videoDataOutput setSampleBufferDelegate:self queue:queue];
dispatch_release(queue);
[session addOutput:videoDataOutput];
NSNotificationCenter *notify =
[NSNotificationCenter defaultCenter];
[notify addObserver: self
selector: #selector(onVideoError:)
name: AVCaptureSessionRuntimeErrorNotification
object: session];
[session startRunning];
[rearCamera lockForConfiguration:nil];
rearCamera.whiteBalanceMode = AVCaptureWhiteBalanceModeContinuousAutoWhiteBalance;
rearCamera.exposureMode = AVCaptureExposureModeContinuousAutoExposure;
rearCamera.focusMode = AVCaptureFocusModeContinuousAutoFocus;
[rearCamera unlockForConfiguration];
The method
captureOutput:(AVCaptureOutput *)captureOutput
didOutputSampleBuffer:(CMSampleBufferRef)sampleBuffer
fromConnection:(AVCaptureConnection *)connection
gets called no problem the first time I present the modal viewcontroller, but on the second attempt this method stops getting called (because the session does not start)
For clean up I'm calling stopSession from my parent viewcontroller before dismissing and that does the following:
if ([session isRunning]) {
[session removeInput:input];
[session stopRunning];
[vImagePreview removeFromSuperview];
vImagePreview = nil;
input = nil;
videoDataOutput = nil;
captureVideoPreviewLayer = nil;
session = nil;
queue = nil;
}
I feel like I've tried all sorts of things such as performing a dispatch_sync(queue, ^{}) on the queue to wait for it to be flushed, but that doesn't seem to make a difference (when calling the dispatch_sync I removed the dispatch_release call in my init camera method). I've also tried using the dispatch_set_finalizer_f(queue, capture_cleanup) method suggested in another question but I don't know what needs to actually go in the capture_cleanup method because all of the examples I find are non-ARC code where they call release on pointer to self. I've also combed through all of the sample code I can find from Apple (SquareCam and AVCam) but these are also non-ARC. Any help would be greatly appreciated.
I realized that I was performing a setFocusPointOfInterest on my rear camera and for some reason it was corrupting the session on relaunch. I don't understand why this caused the issue but I will be looking into that.
You might try converting the SquareCam project to ARC before using the source in your program. I was able to do so by using a __bridge cast in the places the converter was complaining, and also replace the "bail:" goto's with simple if statements.
I'm using the AVFoundation api to create a camera preview view and I'm having trouble cleaning up after I'm done.
The best answer I've found to this problem is in this SO thread, thanks Codo.
However, he doesn't address the deallocation of the AVCaptureVideoPreviewLayer, and that's where I'm having trouble.
In my view controller class I have some initialization code in a startCameraCapture method. Listening to Codo's answer, I'm using dispatch_set_finalizer_f(_captureQueue, capture_cleanup); to register a callback to be called when the queue is truly closed.
I'm also retaining self, to make sure my object doesn't go away before the queue is done calling my object. I then use the capture_cleanup callback to release self.
-(void) startCameraCapture {
_camSession = [[AVCaptureSession alloc] init];
if (_previewLayer == nil) {
_previewLayer = [AVCaptureVideoPreviewLayer layerWithSession:_camSession];
}
_previewLayer.frame = self.compView.bgView.frame;
[self.compView.bgView.layer addSublayer:_previewLayer];
// Get the default camera device
AVCaptureDevice* camera = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo];
// Create a AVCaptureInput with the camera device
NSError *error=nil;
AVCaptureInput* cameraInput = [[AVCaptureDeviceInput alloc] initWithDevice:camera error:&error];
if (cameraInput == nil) {
NSLog(#"Error to create camera capture:%#",error);
}
AVCaptureVideoDataOutput* videoOutput = [[[AVCaptureVideoDataOutput alloc] init] autorelease];
// create a queue to run the capture on
_captureQueue=dispatch_queue_create("captureQueue", NULL);
dispatch_set_context(_captureQueue, self);
dispatch_set_finalizer_f(_captureQueue, capture_cleanup);
// setup our delegate
[videoOutput setSampleBufferDelegate:self queue:_captureQueue];
dispatch_release(_captureQueue);
// retain self as a workouround a queue finalization bug in apples's sdk
// per Stackoverflow answer https://stackoverflow.com/questions/3741121/how-to-properly-release-an-avcapturesession
[self retain];
// configure the pixel format
videoOutput.videoSettings = [NSDictionary dictionaryWithObjectsAndKeys:[NSNumber numberWithUnsignedInt:kCVPixelFormatType_32BGRA], (id)kCVPixelBufferPixelFormatTypeKey,
nil];
// and the size of the frames we want
[_camSession setSessionPreset:AVCaptureSessionPresetMedium];
// Add the input and output
[_camSession addInput:cameraInput];
[_camSession addOutput:videoOutput];
[cameraInput release];
// Start the session
[_camSession startRunning];
}
Here the capture_cleanup callback:
static void capture_cleanup(void* p)
{
LiveCompViewController* ar = (LiveCompViewController*)p;
[ar release]; // releases capture session if dealloc is called
}
Then my cleanup code looks like this:
-(void) stopCameraCapture {
[_camSession stopRunning];
[_camSession release];
_camSession=nil;
// Remove the layer in order to release the camSession
[_previewLayer removeFromSuperlayer];
_previewLayer = nil;
}
The problem I'm having is that removing the _previewLayer from the superlayer in stopCameraCapture is causing the following console error:
"...modifying layer that is being finalized..."
But I need to remove the layer so that it gets released and deallocated so that it releases the _camSession which in turn releases the dispatch_queue and then finally calls my capture_cleanup callback which finally releases self.
I don't understand why I'm getting the console error and how to fix it. Why is the Layer being finalized at the time I'm calling [_previewLayer removeFromSuperlayer] if self.dealloc hasn't been called.
Note: self is a viewController and I haven't popped it yet, so it is retained by the NavigationContoller.
Try stopping the session before releasing:
[captureSession stopRunning];