objective-c - 我正在尝试更改音频的音调，但无法保存受影响的音频。如何在背景中保存效果音频？

Question

此方法过滤音频并更改音调，但不保存在任何地方

-(void)Pitch:(NSNumber*)pitch
{
 audioPlayerNode = [AVAudioPlayerNode new];
[self.audioEngine attachNode:audioPlayerNode];

AVAudioUnitTimePitch *timePitchEffect = [AVAudioUnitTimePitch new];
[self.audioEngine attachNode:timePitchEffect];
    timePitchEffect.pitch = [pitch floatValue];

[self.audioEngine connect:audioPlayerNode
                       to:timePitchEffect
                   format:nil];
[self.audioEngine connect:timePitchEffect
                       to:self.audioEngine.outputNode
                   format:nil];

[audioPlayerNode scheduleFile:self.audioFile
                       atTime:nil
            completionHandler:nil];

[self.audioEngine startAndReturnError:&audioEngineError];
 }

在这里，我可以创建音频文件，但是音频中没有声音，任何人都可以帮助我摆脱这种情况
创建了一个名为outputfile的新文件，但是当我播放该音频时，没有声音只是静音，因此会创建完整的音频，但没有声音

-(void)saveEffectedAudioToFolder

{
AVAudioUnitTimePitch *pitchEffect = [AVAudioUnitTimePitch new];

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];
[recordSetting setValue:[NSNumber numberWithFloat:pitch] forKey:AVAudioTimePitchAlgorithmSpectral];



AVAudioFormat *commonFormat = [[AVAudioFormat alloc] initWithSettings:recordSetting];
pitchEffect.pitch =pitch;

[self setupEQ];


NSError *error12;
[_audioEngine startAndReturnError:&error12];
if (!error12)
{
    NSLog(@"Engine = %@",_audioEngine);
    [audioPlayerNode scheduleFile:_audioFile atTime:nil completionHandler:nil];


    NSError *error;
    _outputFile = [[AVAudioFile alloc] initForWriting:[self testFilePathURL] settings:commonFormat.settings error:&error];
    NSLog(@"outputfile = %@",_outputFile);
    if (error)
    {
        NSLog(@"outputFile error = %@",error);
    }
    else

    {

        [SVProgressHUD dismiss];
        [audioPlayerNode 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
            {
                NSError *error2;



                [audioPlayerNode removeTapOnBus:0];

                // player2 = [[AVAudioPlayer alloc] initWithContentsOfURL:[self testFilePathURL] error:&error2];
                //player2.delegate = self;

                NSLog(@"Pathththt = %@",[self testFilePathURL]);
                NSLog(@"error = %@",error2);
                [audioPlayerNode scheduleFile:_outputFile atTime:nil completionHandler:nil];


                [audioPlayerNode 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 = pitch;
filterParameters.bandwidth = 1.0;
filterParameters.gain = 20.0f;
filterParameters.bypass = FALSE;

filterParameters = _unitEq.bands[1];
filterParameters.filterType = AVAudioUnitEQFilterTypeParametric;
filterParameters.frequency = pitch;
filterParameters.bandwidth = 1.0;
filterParameters.gain = 20.0f;
filterParameters.bypass = FALSE;

filterParameters = _unitEq.bands[2];
filterParameters.filterType = AVAudioUnitEQFilterTypeParametric;
filterParameters.frequency = pitch;
filterParameters.bandwidth = 1.0;
filterParameters.gain = 20.0f;
filterParameters.bypass = FALSE;

filterParameters = _unitEq.bands[3];
filterParameters.filterType = AVAudioUnitEQFilterTypeParametric;
filterParameters.frequency = pitch;
filterParameters.bandwidth = 1.0;
filterParameters.gain = 20.0f;
filterParameters.bypass = FALSE;

filterParameters = _unitEq.bands[4];
filterParameters.filterType = AVAudioUnitEQFilterTypeParametric;
filterParameters.frequency = pitch;
filterParameters.bandwidth = 1.0;
filterParameters.gain = 20.0f;
filterParameters.bypass = FALSE;

filterParameters = _unitEq.bands[5];
filterParameters.filterType = AVAudioUnitEQFilterTypeParametric;
filterParameters.frequency = pitch;
filterParameters.bandwidth = 1.0;
filterParameters.gain = 20.0f;
filterParameters.bypass = FALSE;

filterParameters = _unitEq.bands[6];
filterParameters.filterType = AVAudioUnitEQFilterTypeParametric;
filterParameters.frequency = pitch;
filterParameters.bandwidth = 1.0;
filterParameters.gain = 20.0f;
filterParameters.bypass = FALSE;

filterParameters = _unitEq.bands[7];
filterParameters.filterType = AVAudioUnitEQFilterTypeParametric;
filterParameters.frequency = pitch;
filterParameters.bandwidth = 1.0;
filterParameters.gain =20.0f;
filterParameters.bypass = FALSE;

filterParameters = _unitEq.bands[8];
filterParameters.filterType = AVAudioUnitEQFilterTypeParametric;
filterParameters.frequency = pitch;
filterParameters.bandwidth = 1.0;
filterParameters.gain = 20.0f;
filterParameters.bypass = FALSE;

filterParameters = _unitEq.bands[9];
filterParameters.filterType = AVAudioUnitEQFilterTypeParametric;
filterParameters.frequency = pitch;
filterParameters.bandwidth = 1.0;
filterParameters.gain =20.0f;
filterParameters.bypass = FALSE;


filterParameters = _unitEq.bands[10];
filterParameters.filterType = AVAudioUnitEQFilterTypeLowPass;
filterParameters.frequency = pitch;
filterParameters.bypass = FALSE;

filterParameters = _unitEq.bands[11];
filterParameters.filterType = AVAudioUnitEQFilterTypeHighPass;
filterParameters.frequency = pitch;
filterParameters.bypass = FALSE;
[_audioEngine attachNode:_unitEq];

}

Answer 1

你应该更换

[audioPlayerNode 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
            {
                NSError *error2;



                [audioPlayerNode removeTapOnBus:0];

                // player2 = [[AVAudioPlayer alloc] initWithContentsOfURL:[self testFilePathURL] error:&error2];
                //player2.delegate = self;

                NSLog(@"Pathththt = %@",[self testFilePathURL]);
                NSLog(@"error = %@",error2);
                [audioPlayerNode scheduleFile:_outputFile atTime:nil completionHandler:nil];


                [audioPlayerNode play];
                // [self toMp3];
            }

        }];
    }

用

这里的输入表示audioEngine.inputnode

AVAudioInputNode *input = [audioEngine inputNode]; 
AVAudioFormat *format = [input outputFormatForBus: 0];

outputFile = [[AVAudioFile alloc] initForWriting:[self testFilePathURL] settings:recordSetting error:&error];
    if (error)
    {
        //  NSLog(@"outputFile error = %@",error);
         
    }
    else
    {
        //        dispatch_async(dispatch_get_global_queue( DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^(void)
        //        {
        [input installTapOnBus:0 bufferSize:8091 format:format block:^(AVAudioPCMBuffer * _Nonnull buffer, AVAudioTime * _Nonnull when) {
            
            
            if (outputFile.length<audioFile.length)
            {
                
                NSError *error;
                [outputFile writeFromBuffer:buffer error:&error];
                if (error)
                {
                    NSLog(@"writebuffererror =%@",error);
                    

                }
            }
            else
            {
                
                activityMainView.hidden=YES;
                
                [input removeTapOnBus:0];
                
                //  [self savingAudioFile];
                
                
                //_doneButtonImageView.image=[UIImage imageNamed:@"save"];
                [self doneButtonClick:nil];
                NSError *error2;
                NSLog(@"Pathththt = %@",[self testFilePathURL]);
                NSLog(@"error = %@",error2);
                
               
                
            }
            
            
            
        }];
        
        
         
        //     });
        
        
    }