Record video with AVAssetWriter - ios

Question

I'm trying to record video with AVAssetwriter but I keep getting NO when checking AVAssetWriterInput property readyForMoreMediaData before appending data.
I saw related posts that mentioned similar problem when trying to record audio + video so I took out the audio recording part but the problem still occurs (readyForMoreMediaData is always NO).
My code:
- (void)startRecordingWithAssetWriter {
NSLog(#"Setting up capture session");
captureSession = [[AVCaptureSession alloc] init];
//----- ADD INPUTS -----
NSLog(#"Adding video input");
//ADD VIDEO INPUT
AVCaptureDevice *videoCaptureDevice = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo];
if (videoCaptureDevice) {
NSError *error;
videoInputDevice = [AVCaptureDeviceInput deviceInputWithDevice:videoCaptureDevice error:&error];
if (!error) {
if ([captureSession canAddInput:videoInputDevice]) {
[captureSession addInput:videoInputDevice];
} else {
NSLog(#"Couldn't add video input");
}
} else {
NSLog(#"Couldn't create video input");
}
} else {
NSLog(#"Couldn't create video capture device");
}
//ADD AUDIO INPUT
NSLog(#"Adding audio input");
AVCaptureDevice *audioCaptureDevice = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeAudio];
NSError *error = nil;
AVCaptureDeviceInput *audioInput = [AVCaptureDeviceInput deviceInputWithDevice:audioCaptureDevice error:&error];
NSLog(#"Added audio input: %#", error.description);
if (audioInput) {
[captureSession addInput:audioInput];
}
//----- ADD OUTPUTS -----
captureQueue = dispatch_queue_create("com.recordingtest", DISPATCH_QUEUE_SERIAL);
//-- Create the output for the capture session.
videoOutput = [[AVCaptureVideoDataOutput alloc] init];
[videoOutput setAlwaysDiscardsLateVideoFrames:YES];
[videoOutput setVideoSettings:
[NSDictionary dictionaryWithObject:
[NSNumber numberWithInt:kCVPixelFormatType_420YpCbCr8BiPlanarVideoRange]
forKey:(id)kCVPixelBufferPixelFormatTypeKey]];
[videoOutput setSampleBufferDelegate:self queue:captureQueue];
if ([captureSession canAddOutput:videoOutput]) {
NSLog(#"Added video Output");
[captureSession addOutput:videoOutput];
}
// audioOutput = [[AVCaptureAudioDataOutput alloc] init];
// [audioOutput setSampleBufferDelegate:self queue:captureQueue];
//
// if ([captureSession canAddOutput:audioOutput]) {
// NSLog(#"Added audio Output");
// [captureSession addOutput:audioOutput];
// }
//Create temporary URL to record to
NSString *outputPath = [[NSString alloc] initWithFormat:#"%#%#", NSTemporaryDirectory(), #"output.mp4"];
NSURL *outputURL = [[NSURL alloc] initFileURLWithPath:outputPath];
NSFileManager *fileManager = [NSFileManager defaultManager];
if ([fileManager fileExistsAtPath:outputPath])
{
NSError *error;
if ([fileManager removeItemAtPath:outputPath error:&error] == NO)
{
//Error - handle if requried
}
}
NSError *assetWriterError;
assetWriter = [AVAssetWriter assetWriterWithURL:outputURL fileType:AVFileTypeMPEG4 error:&assetWriterError];
if (assetWriterError) {
NSLog(#"Error Setting assetWriter: %#", assetWriterError);
}
if (assetWriter != nil) {
} else {
NSLog(#"Error Setting assetWriter: %#", assetWriterError);
}
assetWriterVideoIn = [AVAssetWriterInput assetWriterInputWithMediaType:AVMediaTypeVideo outputSettings:nil];
assetWriterVideoIn.expectsMediaDataInRealTime = YES;
// assetWriterAudioIn = [AVAssetWriterInput assetWriterInputWithMediaType:AVMediaTypeAudio outputSettings:nil];
// assetWriterAudioIn.expectsMediaDataInRealTime = YES;
isRecording = YES;
if ([assetWriter canAddInput:assetWriterVideoIn]) {
[assetWriter addInput:assetWriterVideoIn];
}
// if ([assetWriter canAddInput:assetWriterAudioIn]) {
// [assetWriter addInput:assetWriterAudioIn];
// }
[captureSession commitConfiguration];
[captureSession startRunning];
}
- (void)captureOutput:(AVCaptureOutput *)captureOutput
didOutputSampleBuffer:(CMSampleBufferRef)sampleBuffer
fromConnection:(AVCaptureConnection *)connection {
NSLog(#"didOutputSampleBuffer");
CFRetain(sampleBuffer);
dispatch_async(captureQueue, ^{
if (assetWriter) {
if (isRecording) {
if (captureOutput == videoOutput) {
[self writeSampleBuffer:sampleBuffer ofType:AVMediaTypeVideo];
}
// else if (captureOutput == audioOutput) {
// [self writeSampleBuffer:sampleBuffer ofType:AVMediaTypeAudio];
// }
}
}
CFRelease(sampleBuffer);
});
}
- (void)writeSampleBuffer:(CMSampleBufferRef)sampleBuffer ofType:(NSString *)mediaType {
NSLog(#"writeSampleBuffer: %ld", (long) assetWriter.status);
CMTime presentationTime = CMSampleBufferGetPresentationTimeStamp(sampleBuffer);
if (assetWriter.status == AVAssetWriterStatusUnknown) {
if ([assetWriter startWriting]) {
NSLog(#"startSessionAtSourceTime");
[assetWriter startSessionAtSourceTime:presentationTime];
} else {
NSLog(#"Error writing initial buffer");
}
}
if (assetWriter.status == AVAssetWriterStatusWriting) {
if (mediaType == AVMediaTypeVideo) {
NSLog(#"assetWriterVideoIn.readyForMoreMediaData: %d", assetWriterVideoIn.readyForMoreMediaData);
if (assetWriterVideoIn.readyForMoreMediaData) {
NSLog(#"appendSampleBuffer");
if (![assetWriterVideoIn appendSampleBuffer:sampleBuffer]) {
NSLog(#"Error writing video buffer");
}
}
}
// else if (mediaType == AVMediaTypeAudio) {
// if (assetWriterAudioIn.readyForMoreMediaData) {
//
// if (![assetWriterAudioIn appendSampleBuffer:sampleBuffer]) {
// NSLog(#"Error writing audio buffer");
// }
// }
// }
}
}

Answer 1

It finally worked after I set assetWriterVideoIn = [AVAssetWriterInput assetWriterInputWithMediaType:AVMediaTypeVideo outputSettings:nil];
to get some actual settings instead of nil.
Changed to this:
NSDictionary *settings = [NSDictionary dictionaryWithObjectsAndKeys:AVVideoCodecH264, AVVideoCodecKey,
[NSNumber numberWithInt:480], AVVideoWidthKey,[NSNumber numberWithInt:640], AVVideoHeightKey, nil];
assetWriterVideoIn = [AVAssetWriterInput assetWriterInputWithMediaType:AVMediaTypeVideo outputSettings:settings];