-(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; }
我正在使用此功能修剪音乐文件中的音乐文件。当我尝试修剪位于bundle中的文件时，Above代码是工作文件。但是当我尝试使用与iTune音乐库中的输入文件相同的功能时，它不给轨道，即if（[[assetUrl tracksWithMediaType：AVMediaTypeAudio] count] == 0）{ 返回NO; }否。任何人都可以帮助修剪iTunes Libaray中的音乐
答案 0 :(得分：0)
- (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:^{
}];
}
这是用于在文档目录
中创建iTune库和故事的URL的代码答案 1 :(得分：0)
首先，我只想指出您可以通过设置assetReader的timeRange属性来读取库中音频的片段。这样，您可以只复制所需的段，而不是复制整个文件。话虽如此，如果您要坚持原始实现，我认为您只需要将How about Something like the following:
SELECT
r.Heat
,c.ctemp
,s.ShiftIdent
,r.ChargeSeq
,s.rollLocSeq
FROM (NYS1ShiftCut s inner join NYS1CharpyOrders c on c.CharpyOrderID = s.CharpyID)
join NYS1Reheat r on r.LocSeq = s.RollLocSeq
where c.CTemp < +40
AND r.heat IN (SELECT DISTINCT r.HEAT FROM NYS1ShiftCut s inner join NYS1CharpyOrders c on c.CharpyOrderID = s.CharpyID)
join NYS1Reheat r on r.LocSeq = s.RollLocSeq)
order by s.rollLocSeq desc
更改为AVURLAsset *assetUrl = [AVURLAsset assetWithURL:audioFileInput];
答案 2 :(得分：0)
我通过使用以下方法
来保存文档库中的itune音乐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);
}];
}