保存

Question

我已經改變了音頻的時候選擇了瀝青小球在球場一個應用程序，我現在用的installTapOnBus到保存文件的背景音頻文件，但這個方法被invocated後，我因此只按間距按鈕音頻的一部分被保存，我想保存整個音頻無論何時選擇了瀝青小球，有沒有什麼辦法

此方法用於播放音頻

-(void)playAudio 
{ 
    NSError *err = nil; 

    audioEngine = [[AVAudioEngine alloc] init]; 
    AudioFileplayer = [[AVAudioPlayerNode alloc] init]; 
    pitch = [[AVAudioUnitTimePitch alloc] init]; 
    reverb = [[AVAudioUnitReverb alloc] init]; 
    [audioEngine stop]; 
    [AudioFileplayer stop]; 
    [audioEngine reset]; 

    file = [[AVAudioFile alloc] initForReading:[NSURL URLWithString:[self filePath]] error:&err]; 


    [audioEngine attachNode:AudioFileplayer]; 

    [audioEngine attachNode:pitch]; 
    [audioEngine attachNode:reverb]; 

    [audioEngine connect:AudioFileplayer to:reverb format:nil]; 
    [audioEngine connect:reverb to:pitch format:nil]; 
    [audioEngine connect:pitch to:audioEngine.outputNode format:nil]; 
    [reverb loadFactoryPreset:AVAudioUnitReverbPresetLargeRoom2]; 

[AudioFileplayer scheduleFile:file atTime:nil completionHandler:^{ 
     AudioFileplayer = nil; 
    }]; 

    [audioEngine prepare]; 
    [audioEngine startAndReturnError:&err]; 

    if (err != nil) { 
     NSLog(@"An error occured"); 
    } 

    [AudioFileplayer play]; 



} 

這種方法保存音調影響音頻

-(void)saveEffectedAudioToFolder 
{ 
NSError *error; 
if (audioEngine) { 


    pitchEffect.pitch = 1000; 

    AVAudioFormat * commonFormat = [[AVAudioFormat alloc] initWithCommonFormat:AVAudioPCMFormatFloat32 sampleRate:44100 channels:2 interleaved:NO]; 

    // 
    AVAudioFile *outputFile = [[AVAudioFile alloc] initForWriting:[NSURL URLWithString:[self filePath1]] settings:commonFormat.settings error:&error]; 
    // 


    if (error) { 
     NSLog(@"Error is 1 %@",[error localizedDescription]); 


    } 
    [pitchEffect installTapOnBus:0 bufferSize:4096 format:commonFormat block:^(AVAudioPCMBuffer *buffer, AVAudioTime *when) 
    { 

     if (outputFile.length < file.length) 
     {//Let us know when to stop saving the file, otherwise saving infinitely 
      NSError *error; 

      NSAssert([outputFile writeFromBuffer:buffer error:&error], @"error writing buffer data to file, %@", [error localizedDescription]); 

     }else{ 
      audioEngine = nil; 
      [pitchEffect removeTapOnBus:0];//if we dont remove it, will keep on tapping infinitely 

     } 

    } 


    ]; 
} 

} 

任何解決辦法是helful

Answer 1

其實我們在輸出音頻文件的設置出錯了。輸出的音頻文件處理格式應該與輸入文件相同（放置效果或音高）。

和輸出文件格式應在WAV或CAF格式。該格式僅保存到輸出音頻文件。

- (IBAction)save_it_after_changes:(id)sender 
    { 

      engine = [[AVAudioEngine alloc] init]; 
      audio_player_node= [[AVAudioPlayerNode alloc] init]; 
      [engine attachNode:audio_player_node]; 
      [self setupEQ]; 

      AVAudioMixerNode *mixerNode = [engine mainMixerNode]; 
      [engine connect:audio_player_node to:unitEq format:audioFile.processingFormat]; 
      [engine connect:unitEq to:mixerNode format:audioFile.processingFormat]; 

      NSError *error12; 
      [engine startAndReturnError:&error12]; 
      if (!error12) 
      { 
        NSLog(@"Engine = %@",engine); 
       [audio_player_node scheduleFile:audioFile atTime:nil completionHandler:nil]; 
       NSMutableDictionary *recordSetting = [[NSMutableDictionary alloc] init]; 

        [recordSetting setValue :[NSNumber numberWithInt:kAudioFormatLinearPCM] forKey:AVFormatIDKey]; 
        [recordSetting setValue:[NSNumber numberWithFloat:44100.0] forKey:AVSampleRateKey]; 
        [recordSetting setValue:[NSNumber numberWithInt: 2] forKey:AVNumberOfChannelsKey]; 

        [recordSetting setValue :[NSNumber numberWithInt:16] forKey:AVLinearPCMBitDepthKey]; 
        [recordSetting setValue :[NSNumber numberWithBool:NO] forKey:AVLinearPCMIsBigEndianKey]; 
        [recordSetting setValue :[NSNumber numberWithBool:NO] forKey:AVLinearPCMIsFloatKey]; 


        NSError *error; 
       outputFile = [[AVAudioFile alloc] initForWriting:[self testFilePathURL] settings:recordSetting error:&error]; 
        NSLog(@"outputfile = %@",outputFile); 
        if (error) 
        { 
         NSLog(@"outputFile error = %@",error); 
        } 
        else 
        { //(AVAudioFrameCount)audioFile.length 
         [audio_player_node installTapOnBus:0 bufferSize:8192 format:audioFile.processingFormat block:^(AVAudioPCMBuffer *buffer, AVAudioTime *when) { 
           NSLog(@"Buffer Size = %@",buffer); 
           NSLog(@"when = %lld",when.sampleTime); 
           NSLog(@"outputfile length = %lli",outputFile.length); 
           NSLog(@"input file length = %lld",audioFile.length); 
           if (outputFile.length<audioFile.length) 
           { 
            NSError *error; 
            [outputFile writeFromBuffer:buffer error:&error]; 
            if (error) 
            { 
              NSLog(@"writebuffererror =%@",error); 
            } 
           } 
           else 
           { 
            [audio_player_node removeTapOnBus:0]; 
            NSError *error2; 
            // player2 = [[AVAudioPlayer alloc] initWithContentsOfURL:[self testFilePathURL] error:&error2]; 
            //player2.delegate = self; 
            NSLog(@"Pathththt = %@",[self testFilePathURL]); 
            NSLog(@"error = %@",error2); 
            // [audio_player_node scheduleFile:outputFile atTime:nil completionHandler:nil]; 
            //[audio_player_node play]; 
            // [self toMp3]; 
           } 

         }]; 
        } 
      } 
      else 
      { 
        NSLog(@"error12 =%@",error12); 
      } 

    } 





- (void)setupEQ 
{ 
     NSLog(@"setupEQ"); 

     unitEq = [[AVAudioUnitEQ alloc] initWithNumberOfBands:12]; 
     unitEq.globalGain = 3.0; 
     AVAudioUnitEQFilterParameters *filterParameters; 
     filterParameters = unitEq.bands[0]; 
     filterParameters.filterType = AVAudioUnitEQFilterTypeParametric; 
     filterParameters.frequency = 31; 
     filterParameters.bandwidth = 1.0; 
     filterParameters.gain = -20; 
     filterParameters.bypass = FALSE; 

     filterParameters = unitEq.bands[1]; 
     filterParameters.filterType = AVAudioUnitEQFilterTypeParametric; 
     filterParameters.frequency = 63; 
     filterParameters.bandwidth = 1.0; 
     filterParameters.gain = -20; 
     filterParameters.bypass = FALSE; 

     filterParameters = unitEq.bands[2]; 
     filterParameters.filterType = AVAudioUnitEQFilterTypeParametric; 
     filterParameters.frequency = 125; 
     filterParameters.bandwidth = 1.0; 
     filterParameters.gain = -20; 
     filterParameters.bypass = FALSE; 

     filterParameters = unitEq.bands[3]; 
     filterParameters.filterType = AVAudioUnitEQFilterTypeParametric; 
     filterParameters.frequency = 250; 
     filterParameters.bandwidth = 1.0; 
     filterParameters.gain = -20; 
     filterParameters.bypass = FALSE; 

     filterParameters = unitEq.bands[4]; 
     filterParameters.filterType = AVAudioUnitEQFilterTypeParametric; 
     filterParameters.frequency = 500; 
     filterParameters.bandwidth = 1.0; 
     filterParameters.gain = -20; 
     filterParameters.bypass = FALSE; 

     filterParameters = unitEq.bands[5]; 
     filterParameters.filterType = AVAudioUnitEQFilterTypeParametric; 
     filterParameters.frequency = 1000; 
     filterParameters.bandwidth = 1.0; 
     filterParameters.gain = -20; 
     filterParameters.bypass = FALSE; 

     filterParameters = unitEq.bands[6]; 
     filterParameters.filterType = AVAudioUnitEQFilterTypeParametric; 
     filterParameters.frequency = 2000; 
     filterParameters.bandwidth = 1.0; 
     filterParameters.gain = -20; 
     filterParameters.bypass = FALSE; 

     filterParameters = unitEq.bands[7]; 
     filterParameters.filterType = AVAudioUnitEQFilterTypeParametric; 
     filterParameters.frequency = 4000; 
     filterParameters.bandwidth = 1.0; 
     filterParameters.gain =-20; 
     filterParameters.bypass = FALSE; 

     filterParameters = unitEq.bands[8]; 
     filterParameters.filterType = AVAudioUnitEQFilterTypeParametric; 
     filterParameters.frequency = 8000; 
     filterParameters.bandwidth = 1.0; 
     filterParameters.gain = -20; 
     filterParameters.bypass = FALSE; 

     filterParameters = unitEq.bands[9]; 
     filterParameters.filterType = AVAudioUnitEQFilterTypeParametric; 
     filterParameters.frequency = 16000; 
     filterParameters.bandwidth = 1.0; 
     filterParameters.gain =-20; 
     filterParameters.bypass = FALSE; 


     filterParameters = unitEq.bands[10]; 
     filterParameters.filterType = AVAudioUnitEQFilterTypeLowPass; 
     filterParameters.frequency = 16857; 
     filterParameters.bypass = FALSE; 

     filterParameters = unitEq.bands[11]; 
     filterParameters.filterType = AVAudioUnitEQFilterTypeHighPass; 
     filterParameters.frequency = 205; 
     filterParameters.bypass = FALSE; 
     [engine attachNode:unitEq]; 
} 




- (NSString *)applicationDocumentsDirectory 
{ 
     NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES); 
     NSString *basePath = ([paths count] > 0) ? [paths objectAtIndex:0] : nil; 
     return basePath; 
} 

//------------------------------------------------------------------------------ 

- (NSURL *)testFilePathURL 
{ 
     return [NSURL fileURLWithPath:[NSString stringWithFormat:@"%@/test.caf", 
            [self applicationDocumentsDirectory]]]; 
} 

請保存成功後播放文件。這個對我有用。一探究竟。

請參考以下鏈接，我得到更多來自這裏，Can I use AVAudioEngine to read from a file, process with an audio unit and write to a file, faster than real-time?

參照此示例項目。這就是我們正在尋找的 https://github.com/VladimirKravchenko/AVAudioEngineOfflineRender