Copy item from iPod Library - xamarin.ios

Question

I'm trying to copy an item from the iPod Library to my local storage space - for later playback. I've got the item URl but it's (ipod-library://item/item.mp3?id=2398084975506389321) any idea how to access the actual file?
Thanks,
Rick

Answer 1

This will work https://gist.github.com/3304992
-(void)mediaPicker:(MPMediaPickerController *)mediaPicker didPickMediaItems:(MPMediaItemCollection *)mediaItemCollection{
NSString *tempPath = NSTemporaryDirectory();
int i=1;
for (MPMediaItem *theItem in mediaItemCollection.items) {
NSURL *url = [theItem valueForProperty:MPMediaItemPropertyAssetURL];
AVURLAsset *songAsset = [AVURLAsset URLAssetWithURL:url options:nil];
AVAssetExportSession *exporter = [[AVAssetExportSession alloc] initWithAsset: songAsset presetName: AVAssetExportPresetPassthrough];
exporter.outputFileType = #"com.apple.coreaudio-format";
NSString *fname = [[NSString stringWithFormat:#"%d",i] stringByAppendingString:#".caf"];
++i;
NSString *exportFile = [tempPath stringByAppendingPathComponent: fname];
exporter.outputURL = [NSURL fileURLWithPath:exportFile];
[exporter exportAsynchronouslyWithCompletionHandler:^{
//Code for completion Handler
}];
}
[picker dismissViewControllerAnimated:YES completion:Nil];
}
use MPMediaPickerController to pick the media

Answer 2

This is how I'm doing it in Objective-C:
#import <CoreMedia/CoreMedia.h>
#import <AVFoundation/AVFoundation.h>
#import <CoreAudio/CoreAudio.h>
// or [NSURL URLWithString:#"ipod-library://item/item.mp3?id=2398084975506389321"]
NSURL *assetURL = [item valueForProperty:MPMediaItemPropertyAssetURL];
NSMutableData *data = [[NSMutableData alloc] init];
const uint32_t sampleRate = 16000;
const uint16_t bitDepth = 16;
const uint16_t channels = 2;
NSDictionary *opts = [NSDictionary dictionary];
AVURLAsset *asset = [[AVURLAsset alloc] initWithURL:assetURL options:opts];
AVAssetReader *reader = [[AVAssetReader alloc] initWithAsset:asset error:NULL];
NSDictionary *settings = [NSDictionary dictionaryWithObjectsAndKeys:
[NSNumber numberWithInt:kAudioFormatLinearPCM], AVFormatIDKey,
[NSNumber numberWithFloat:(float)sampleRate], AVSampleRateKey,
[NSNumber numberWithInt:bitDepth], AVLinearPCMBitDepthKey,
[NSNumber numberWithBool:NO], AVLinearPCMIsNonInterleaved,
[NSNumber numberWithBool:NO], AVLinearPCMIsFloatKey,
[NSNumber numberWithBool:NO], AVLinearPCMIsBigEndianKey,
nil];
AVAssetReaderTrackOutput *output = [[AVAssetReaderTrackOutput alloc] initWithTrack:[[asset tracks] objectAtIndex:0] outputSettings:settings];
[asset release];
[reader addOutput:output];
[reader startReading];
// read the samples from the asset and append them subsequently
while ([reader status] != AVAssetReaderStatusCompleted) {
CMSampleBufferRef buffer = [output copyNextSampleBuffer];
if (buffer == NULL) continue;
CMBlockBufferRef blockBuffer = CMSampleBufferGetDataBuffer(buffer);
size_t size = CMBlockBufferGetDataLength(blockBuffer);
uint8_t *outBytes = malloc(size);
CMBlockBufferCopyDataBytes(blockBuffer, 0, size, outBytes);
CMSampleBufferInvalidate(buffer);
CFRelease(buffer);
[data appendBytes:outBytes length:size];
free(outBytes);
}
[output release];
Here data will contain the raw PCM data of the track. Please note that you cannot directly access the file of a song or video, only its data through this method. You can compress it using e. g. FLAC (that's how I'm processing it in my tweak).
Since MonoTouch has an 1:1 mapping to Objective-C class and method names, this should be fairly easy to copy over. :)