Похоже, что файл моей песни, который я пытаюсь получить из пользовательской библиотеки, увеличивается до 50 МБ после кода ниже.Тем не менее, я знаю, что эта песня будет 7,2 МБ.Я хотел бы прикрепить музыкальный файл (без DRM) к электронному письму, но 50 МБ явно слишком велики.Код, который я использую ниже.Любая помощь будет оценена:)
-(void)findSong {
MPMediaQuery *query = [MPMediaQuery songsQuery];
NSArray *songsQuery = [query collections];
//create media item
MPMediaItemCollection *mySong = [songsQuery objectAtIndex:1];
NSLog(@"song name: %@",[[mySong representativeItem]valueForProperty:MPMediaItemPropertyTitle]);
NSURL *assetURL = [[mySong representativeItem]valueForProperty:MPMediaItemPropertyAssetURL];
AVURLAsset *songAsset = [AVURLAsset URLAssetWithURL:assetURL options:nil];
NSError *assetError = nil;
AVAssetReader *assetReader = [[AVAssetReader assetReaderWithAsset:songAsset
error:&assetError]
retain];
if (assetError) {
NSLog (@"error: %@", assetError);
return;
}
AVAssetReaderOutput *assetReaderOutput = [[AVAssetReaderAudioMixOutput
assetReaderAudioMixOutputWithAudioTracks:songAsset.tracks
audioSettings: nil]
retain];
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:EXPORT_NAME] retain];
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]
retain];
if (assetError) {
NSLog (@"error: %@", assetError);
return;
}
AudioChannelLayout channelLayout;
memset(&channelLayout, 0, sizeof(AudioChannelLayout));
channelLayout.mChannelLayoutTag = kAudioChannelLayoutTag_Stereo;
NSDictionary *outputSettings = [NSDictionary dictionaryWithObjectsAndKeys:
[NSNumber numberWithInt:kAudioFormatLinearPCM], AVFormatIDKey,
[NSNumber numberWithFloat:44100.0], AVSampleRateKey,
[NSNumber numberWithInt:2], AVNumberOfChannelsKey,
[NSData dataWithBytes:&channelLayout length:sizeof(AudioChannelLayout)], AVChannelLayoutKey,
[NSNumber numberWithInt:16], AVLinearPCMBitDepthKey,
[NSNumber numberWithBool:NO], AVLinearPCMIsNonInterleaved,
[NSNumber numberWithBool:NO],AVLinearPCMIsFloatKey,
[NSNumber numberWithBool:NO], AVLinearPCMIsBigEndianKey,
nil];
AVAssetWriterInput *assetWriterInput = [[AVAssetWriterInput assetWriterInputWithMediaType:AVMediaTypeAudio
outputSettings:outputSettings]
retain];
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: ^
{
// NSLog (@"top of block");
while (assetWriterInput.readyForMoreMediaData) {
CMSampleBufferRef nextBuffer = [assetReaderOutput copyNextSampleBuffer];
if (nextBuffer) {
// append buffer
[assetWriterInput appendSampleBuffer: nextBuffer];
// NSLog (@"appended a buffer (%d bytes)",
// CMSampleBufferGetTotalSampleSize (nextBuffer));
convertedByteCount += CMSampleBufferGetTotalSampleSize (nextBuffer);
} else {
// done!
[assetWriterInput markAsFinished];
[assetWriter finishWriting];
[assetReader cancelReading];
NSDictionary *outputFileAttributes = [[NSFileManager defaultManager]
attributesOfItemAtPath:exportPath
error:nil];
NSLog(@"export path: %@",exportPath);
NSLog (@"done. file size is %ld",[outputFileAttributes fileSize]);
NSURL *exportURL = [NSURL fileURLWithPath:exportPath];
NSData *data = [NSData dataWithContentsOfURL:exportURL];
data = [ChannelViewController gzipData:data];
[self performSelectorOnMainThread:@selector(sendMailWithData:)
withObject:data
waitUntilDone:NO];
// release a lot of stuff
[assetReader release];
[assetReaderOutput release];
[assetWriter release];
[assetWriterInput release];
[exportPath release];
break;
}
}
}];
NSLog (@"bottom of convertTapped:");
}