How to trim Music Library file and save it document directry - objective-c

Question

-(BOOL)trimAudioFileAtPath:(NSString *)inputFilename
start:(float)start
end:(float) stop{
NSString *outputFilename = #"File Path";
NSError *error = nil; NSFileManager *fileManager = [NSFileManager defaultManager]; if ([fileManager fileExistsAtPath:outputFilename]) {
if (![fileManager removeItemAtPath:outputFilename error:&error]) {
DebugLog(#"error file remove:%#",error); } else {
DebugLog(#"sucess remove file");
} }
NSURL *audioFileInput = [NSURL fileURLWithPath:inputFilename];
NSURL *audioFileOutput = [NSURL fileURLWithPath:outputFilename];
if (!audioFileInput || !audioFileOutput){ return NO; }
[[NSFileManager defaultManager] removeItemAtURL:audioFileOutput error:NULL];
AVMutableComposition *mutableComposition = [AVMutableComposition composition]; // Create the video composition track.
AVMutableCompositionTrack *mutableCompositionAudioTrack = [mutableComposition addMutableTrackWithMediaType:AVMediaTypeAudio preferredTrackID:kCMPersistentTrackID_Invalid];
NSLog(#"audioFileInput %#",audioFileInput); AVURLAsset *assetUrl = [AVURLAsset assetWithURL:audioFileInput];
if ([[assetUrl tracksWithMediaType:AVMediaTypeAudio] count]==0) { return NO; }
// Get the first music track from each asset. AVAssetTrack *audioAssetTrack = [[assetUrl tracksWithMediaType:AVMediaTypeAudio] objectAtIndex:0]; [mutableCompositionAudioTrack insertTimeRange:CMTimeRangeMake(kCMTimeZero,audioAssetTrack.timeRange.duration) ofTrack:audioAssetTrack atTime:kCMTimeZero error:nil];
// we need the audio asset to be at least 50 seconds long for this snippet
CMTime startTime = CMTimeMake(start, 1);
CMTime stopTime = CMTimeMake(stop, 1);
CMTimeRange exportTimeRange = CMTimeRangeFromTimeToTime(startTime,stopTime);
Float64 duration = CMTimeGetSeconds(exportTimeRange.duration);
// Create the export session with the composition and set the preset to the highest quality.
AVAssetExportSession *exportSession = [[AVAssetExportSession alloc] initWithAsset:mutableComposition presetName:AVAssetExportPresetAppleM4A];
if (duration > 6.0){
AVMutableAudioMix *mutableAudioMix = [AVMutableAudioMix audioMix];
// Create the audio mix input parameters object.
AVMutableAudioMixInputParameters *mixParameters = [AVMutableAudioMixInputParameters audioMixInputParametersWithTrack:mutableCompositionAudioTrack];
// float totalDutaion=mutableComposition.duration.value;
float totalDutaion=duration;
float lenth=totalDutaion/3;
CMTime startCM = CMTimeMake(totalDutaion-lenth-1,mutableComposition.duration.timescale);
CMTime endCM = CMTimeMake(lenth, mutableComposition.duration.timescale);
// Set the volume ramp to slowly fade the audio out over the duration of the composition.
[mixParameters setVolumeRampFromStartVolume:0.f toEndVolume:1.f timeRange:CMTimeRangeMake(startTime, endCM)];
[mixParameters setVolumeRampFromStartVolume:1.f toEndVolume:0.f timeRange:CMTimeRangeMake(startCM,endCM)];
// Attach the input parameters to the audio mix.
mutableAudioMix.inputParameters = #[mixParameters];
exportSession.audioMix=mutableAudioMix; }
if (exportSession == nil){
return NO; }
exportSession.outputURL = audioFileOutput; exportSession.outputFileType = AVFileTypeAppleM4A; exportSession.timeRange = exportTimeRange;
[exportSession exportAsynchronouslyWithCompletionHandler:^ {
if (AVAssetExportSessionStatusCompleted == exportSession.status)
{
// It worked!
}
else if (AVAssetExportSessionStatusFailed == exportSession.status)
{
// It failed...
} }]; return YES; }
I am using this function to trim the music file from music libaray. The Above code is working file when I try to trim a file which is located in bundle. But When I try to use the same function with input file from iTune music Library it is give no Tracks i.e. if ([[assetUrl tracksWithMediaType:AVMediaTypeAudio] count]==0) {
return NO;
} return No. Can anyone help to trim music from iTunes Libaray

Answer 1

- (void) mediaPicker: (MPMediaPickerController *) mediaPicker didPickMediaItems: (MPMediaItemCollection *) mediaItemCollection
{
if (mediaItemCollection) {
NSLog(#"%#",[mediaItemCollection items]);
// [musicPlayer setQueueWithItemCollection: mediaItemCollection];
// [musicPlayer play];
}
[KVNProgress showWithStatus:#"Processing"];
MPMediaItem *item =mediaItemCollection.representativeItem;
NSURL* assetURL = [item valueForProperty:MPMediaItemPropertyAssetURL];
// set up an AVAssetReader to read from the iPod Library
AVURLAsset *songAsset =
[AVURLAsset URLAssetWithURL:assetURL options:nil];
NSError *assetError = nil;
AVAssetReader *assetReader =[AVAssetReader assetReaderWithAsset:songAsset error:&assetError];
if (assetError) {
NSLog (#"error: %#", assetError);
return;
}
AVAssetReaderOutput *assetReaderOutput =[AVAssetReaderAudioMixOutput assetReaderAudioMixOutputWithAudioTracks:songAsset.tracks
audioSettings: nil];
if (! [assetReader canAddOutput: assetReaderOutput]) {
NSLog (#"can't add reader output... die!");
return;
}
[assetReader addOutput: assetReaderOutput];
// NSArray *dirs = NSSearchPathForDirectoriesInDomains
// (NSDocumentDirectory, NSUserDomainMask, YES);
// NSString *documentsDirectoryPath = [dirs objectAtIndex:0];
// NSString *exportPath = [documentsDirectoryPath stringByAppendingPathComponent:#"out.m4a"];
NSString * exportPath =[NSString stringWithFormat:#"%#%#", NSTemporaryDirectory(), #"out.m4a"];
if ([[NSFileManager defaultManager] fileExistsAtPath:exportPath]) {
[[NSFileManager defaultManager] removeItemAtPath:exportPath
error:nil];
}
NSURL *exportURL = [NSURL fileURLWithPath:exportPath];
AVAssetWriter *assetWriter =[AVAssetWriter assetWriterWithURL:exportURL
fileType:AVFileTypeCoreAudioFormat
error:&assetError];
if (assetError) {
NSLog (#"error: %#", assetError);
return;
}
AudioChannelLayout channelLayout;
memset(&channelLayout, 0, sizeof(AudioChannelLayout));
channelLayout.mChannelLayoutTag = kAudioChannelLayoutTag_Stereo;
NSDictionary *outputSettings =[NSDictionary dictionaryWithObjectsAndKeys:
#(kAudioFormatLinearPCM), AVFormatIDKey,
#44100.0, AVSampleRateKey,
#2, AVNumberOfChannelsKey,
[NSData dataWithBytes:&channelLayout length:sizeof(AudioChannelLayout)],AVChannelLayoutKey,
#16, AVLinearPCMBitDepthKey,
#NO, AVLinearPCMIsNonInterleaved,
#NO,AVLinearPCMIsFloatKey,
#NO, AVLinearPCMIsBigEndianKey,
nil];
AVAssetWriterInput *assetWriterInput =[AVAssetWriterInput assetWriterInputWithMediaType:AVMediaTypeAudio
outputSettings:outputSettings];
if ([assetWriter canAddInput:assetWriterInput]) {
[assetWriter addInput:assetWriterInput];
} else {
NSLog (#"can't add asset writer input... die!");
return;
}
assetWriterInput.expectsMediaDataInRealTime = NO;
[assetWriter startWriting];
[assetReader startReading];
AVAssetTrack *soundTrack = [songAsset.tracks objectAtIndex:0];
CMTime startTime = CMTimeMake (0, soundTrack.naturalTimeScale);
[assetWriter startSessionAtSourceTime: startTime];
__block UInt64 convertedByteCount = 0;
dispatch_queue_t mediaInputQueue =
dispatch_queue_create("mediaInputQueue", NULL);
[assetWriterInput requestMediaDataWhenReadyOnQueue:mediaInputQueue
usingBlock: ^
{
while (assetWriterInput.readyForMoreMediaData) {
CMSampleBufferRef nextBuffer =
[assetReaderOutput copyNextSampleBuffer];
if (nextBuffer) {
// append buffer
[assetWriterInput appendSampleBuffer: nextBuffer];
// update ui
convertedByteCount +=
CMSampleBufferGetTotalSampleSize (nextBuffer);
} else {
// done!
[assetWriterInput markAsFinished];
[assetWriter finishWritingWithCompletionHandler:^{
[assetReader cancelReading];
[self performSelectorOnMainThread:#selector(updateCompletedAtMusicPath:)
withObject:exportPath
waitUntilDone:NO];
// NSLog (#"done. file size is %llu",[outputFileAttributes fileSize]);
}];
break;
}}}];
[self dismissViewControllerAnimated:NO completion:^{
}];
}
This is code used for geting the URL form iTune Library and story in document directry

Answer 2

First i just want to point out that you can just read segments of the audio from the library by setting the timeRange property of your assetReader. This way instead of copying over the whole file first you can just copy the segments you need. That being said, if you are going to stick with your original implementation, i think you just need to change AVURLAsset *assetUrl = [AVURLAsset assetWithURL:audioFileInput]; to AVURLAsset *assetUrl = [[AVURLAsset URLAssetWithURL:audioFileInput options:nil];

Answer 3

I Got sucess to save itune music in document libray by using following Method
NSArray* paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString* documentsDirectory = [paths objectAtIndex:0];
self.fullPathToFileForAudio = [documentsDirectory stringByAppendingPathComponent:#"auto-old.m4a"];
NSFileManager *fileMgr = [NSFileManager defaultManager];
// get rid of existing mp4 if exists...
if ([fileMgr removeItemAtPath:self.fullPathToFileForAudio error:&error] != YES)
NSLog(#"Unable to delete file: %#", [error localizedDescription]);
[self convertVideoToLowQuailtyWithInputURL:self.musicUrl outputURL:[NSURL fileURLWithPath:self.fullPathToFileForAudio] handler:^(AVAssetExportSession *exportSession)
{
if (exportSession.status == AVAssetExportSessionStatusCompleted)
{
NSLog(#"completed %#",exportSession.error);
printf("completed\n");
dispatch_sync(dispatch_get_main_queue(), ^{
NSLog(#"%# PATH",self.fullPathToFileForAudio);
[self exporterCompleted:[NSURL fileURLWithPath:self.fullPathToFileForAudio]];
});
}
else
{
// NSLog(#"%#",exportSession.error);
printf("error\n");
dispatch_sync(dispatch_get_main_queue(), ^{
[SVProgressHUD dismiss];
});
}
}];
- (void)convertVideoToLowQuailtyWithInputURL:(NSURL*)inputURL
outputURL:(NSURL*)outputURL
handler:(void (^)(AVAssetExportSession*))handler
{
[[NSFileManager defaultManager] removeItemAtURL:outputURL error:nil];
AVURLAsset *asset = [AVURLAsset URLAssetWithURL:inputURL options:nil];
AVAssetExportSession *exportSession = [[AVAssetExportSession alloc] initWithAsset:asset presetName:AVAssetExportPresetAppleM4A];
CMTime startTime = CMTimeMake(minValue, 1);
CMTime stopTime = CMTimeMake(maxValue, 1);
CMTimeRange exportTimeRange = CMTimeRangeFromTimeToTime(startTime, stopTime);
exportSession.outputURL = outputURL;
exportSession.outputFileType = #"com.apple.m4a-audio";
exportSession.timeRange = exportTimeRange;
[exportSession exportAsynchronouslyWithCompletionHandler:^(void)
{
handler(exportSession);
}];
}