• iPhone的录音和播放



    最近准备做一个关于录音和播放的项目!查了一些资料,很简单的做了一个,下面我就分享一下iPhone的录音和播放的使用心得。
    iPhone的录音和播放使用到了media层的内容,media层处于cocoa层之下,用到的很大一部分都是c语言的结构。
    1、引入框架。
    #import <AVFoundation/AVFoundation.h>
    2、创建录音项。
    - (void) prepareToRecord

    {

    AVAudioSession *audioSession = [AVAudioSession sharedInstance];

    NSError *err = nil;

    [audioSession setCategory :AVAudioSessionCategoryPlayAndRecord error:&err];

    if(err){

            NSLog(@"audioSession: %@ %d %@", [err domain], [err code], [[err userInfo] description]);

            return;

    }

    [audioSession setActive:YES error:&err];

    err = nil;

    if(err){

            NSLog(@"audioSession: %@ %d %@", [err domain], [err code], [[err userInfo] description]);

            return;

    }

    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];

     

    // Create a new dated file

    NSDate *now = [NSDate dateWithTimeIntervalSinceNow:0];

    NSString *caldate = [now description];

    recorderFilePath = [[NSString stringWithFormat:@"%@/%@.caf", DOCUMENTS_FOLDER, caldate] retain];

     

    NSURL *url = [NSURL fileURLWithPath:recorderFilePath];

    err = nil;

    recorder = [[ AVAudioRecorder alloc] initWithURL:url settings:recordSetting error:&err];

    if(!recorder){

            NSLog(@"recorder: %@ %d %@", [err domain], [err code], [[err userInfo] description]);

            UIAlertView *alert =

            [[UIAlertView alloc] initWithTitle: @"Warning"

      message: [err localizedDescription]

      delegate: nil

    cancelButtonTitle:@"OK"

    otherButtonTitles:nil];

            [alert show];

            [alert release];

            return;

    }

     

    //prepare to record

    [recorder setDelegate:self];

    [recorder prepareToRecord];

    recorder.meteringEnabled = YES;

     

    BOOL audioHWAvailable = audioSession.inputIsAvailable;

    if (! audioHWAvailable) {

            UIAlertView *cantRecordAlert =

            [[UIAlertView alloc] initWithTitle: @"Warning"

      message: @"Audio input hardware not available"

      delegate: nil

    cancelButtonTitle:@"OK"

    otherButtonTitles:nil];

            [cantRecordAlert show];

            [cantRecordAlert release]; 

            return;

    }

    }


    以上这个方法就是创建了录音项,其中包括录音的路径和一些音频属性,但只是准备录音还没有录,如果要录的话还要加入以下的方法:
    -(void)startrecorder

    {

    [recorder record];

    }

    这样就在我们创建的路径下开始了录音。完成录音很简单:

    - (void) stopRecording{

     

    [recorder stop];

     

     

    }

     

    这里顺便提一下录音的代理方法:

     

    - (void)audioRecorderDidFinishRecording:(AVAudioRecorder *) aRecorder successfully:(BOOL)flag

    {

    NSLog(@"recorder successfully");

    UIAlertView *recorderSuccessful = [[UIAlertView alloc] initWithTitle:@"" message:@"录音成功"delegate:self cancelButtonTitle:@"OK" otherButtonTitles:nil];

    [recorderSuccessful show];

    [recorderSuccessful release];

    }

    - (void)audioRecorderEncodeErrorDidOccur:(AVAudioRecorder *)arecorder error:(NSError *)error

    {

    btnRecorder.enabled = NO;

    UIAlertView *recorderFailed = [[UIAlertView alloc] initWithTitle:@"" message:@"发生错误"delegate:self cancelButtonTitle:@"OK" otherButtonTitles:nil];

    [recorderFailed show];

    [recorderFailed release];

    }

    以上两个代理方法分别指定了录音的成功或失败。

    录音中有一个的录音对象有一个averagePowerForChannel和peakPowerForChannel的属性分别为声音的最高振幅和平均振幅,有了他们就可以做一个动态的振幅的录音效果。

    - (void) updateAudioDisplay {

    if (isStart == NO) {

    currentTimeLabel.text = @"--:--";

    } else {

    double currentTime = recorder.currentTime;

    currentTimeLabel.text = [NSString stringWithFormat: @"d:d",

    (int) currentTime/60,

    (int) currentTime%60];

    //START:code.RecordViewController.setlevelmeters

    [recorder updateMeters];

    [leftLevelMeter setPower: [recorder averagePowerForChannel:0]

    peak: [recorder peakPowerForChannel: 0]];

    if (! rightLevelMeter.hidden) {

    [rightLevelMeter setPower: [recorder averagePowerForChannel:1]

    peak: [recorder peakPowerForChannel: 1]];

    }

    //END:code.RecordViewController.setlevelmeters

    }

    }

    以上就是录音相关的内容。

     

    下面说一下播放的方法:

     

    void SystemSoundsDemoCompletionProc (

    SystemSoundID  soundID,

    void           *clientData)

    {

    AudioServicesDisposeSystemSoundID (soundID);

    ((AudioRecorderPlayerAppDelegate*)clientData).statusLabel.text = @"Stopped";

    };

     

    -(void)playAudio

    {

    //START:code.SystemSoundsDemo.SystemSoundsDemoViewController.createsystemsound

    // create a system sound id for the selected row

    SystemSoundID soundID;

     

    OSStatus err = kAudioServicesNoError;

     

    // special case: vibrate//震动

    //soundID = kSystemSoundID_Vibrate; //<label id="code.SystemSoundsDemo.SystemSoundsDemoViewController.createsystemsound.vibratesystemsound"/>

    // find corresponding CAF file

    //NSString *cafName = [NSString stringWithFormat: @"%@",recorderFilePath]; //<label id="code.SystemSoundsDemo.SystemSoundsDemoViewController.createsystemsound.rowtonumberstring"/>

    NSURL *url = [NSURL fileURLWithPath:recorderFilePath];

     

    //NSString *cafPath = 

    //[[NSBundle mainBundle] pathForResource:cafName ofType:@"caf"]; //<label id="code.SystemSoundsDemo.SystemSoundsDemoViewController.createsystemsound.findcafinbundle"/>

    //NSURL *cafURL = [NSURL fileURLWithPath:url]; //<label id="code.SystemSoundsDemo.SystemSoundsDemoViewController.createsystemsound.fileurlwithpath"/>

    err = AudioServicesCreateSystemSoundID((CFURLRef) url, &soundID); //<label id="code.SystemSoundsDemo.SystemSoundsDemoViewController.createsystemsound.createsystemsound"/>

    //END:code.SystemSoundsDemo.SystemSoundsDemoViewController.createsystemsound

    //START:code.SystemSoundsDemo.SystemSoundsDemoViewController.registercompletionprocandplaysound

    if (err == kAudioServicesNoError) {

    // set up callback for sound completion

    err = AudioServicesAddSystemSoundCompletion //<label id="code.SystemSoundsDemo.SystemSoundsDemoViewController.createsystemsound.addcompletionproc"/>

    (soundID,// sound to monitor

    NULL,// run loop (NULL==main)

    NULL,// run loop mode (NULL==default)

    SystemSoundsDemoCompletionProc, // callback function //<label id="code.SystemSoundsDemo.SystemSoundsDemoViewController.createsystemsound.completionprocroutine"/>

    self // data to provide on callback

    ); //<label id="code.SystemSoundsDemo.SystemSoundsDemoViewController.createsystemsound.addcompletionprocend"/>

    statusLabel.text = @"Playing"; //<label id="code.SystemSoundsDemo.SystemSoundsDemoViewController.createsystemsound.setlabel"/>

    AudioServicesPlaySystemSound (soundID); //<label id="code.SystemSoundsDemo.SystemSoundsDemoViewController.createsystemsound.playsound"/>

    }

    if (err != kAudioServicesNoError) { //<label id="code.SystemSoundsDemo.SystemSoundsDemoViewController.createsystemsound.errorblockstart"/>

    CFErrorRef error = CFErrorCreate(NULL, kCFErrorDomainOSStatus, err, NULL); //<label id="code.SystemSoundsDemo.SystemSoundsDemoViewController.createsystemsound.createcferror"/>

    NSString *errorDesc = (NSString*) CFErrorCopyDescription (error); //<label id="code.SystemSoundsDemo.SystemSoundsDemoViewController.createsystemsound.copycferrordescription"/>

    UIAlertView *cantPlayAlert =

    [[UIAlertView alloc] initWithTitle:@"Cannot Play:"

      message: errorDesc

      delegate:nil

    cancelButtonTitle:@"OK"

    otherButtonTitles:nil];

    [cantPlayAlert show];

    [cantPlayAlert release]; 

    [errorDesc release]; //<label id="code.SystemSoundsDemo.SystemSoundsDemoViewController.createsystemsound.releaseerrordescription"/>

    CFRelease (error); //<label id="code.SystemSoundsDemo.SystemSoundsDemoViewController.createsystemsound.releaseerror"/>

    } //<label id="code.SystemSoundsDemo.SystemSoundsDemoViewController.createsystemsound.errorblockend"/>

    //END:code.SystemSoundsDemo.SystemSoundsDemoViewController.registercompletionprocandplaysound

    }

     


    通过以上的方法就应该能够实现播放,播放的时候也是可以加入振幅过程的,大家可以试试!这样一个iPhone录音机就做好了!哈哈
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  • 原文地址:https://www.cnblogs.com/qq78292959/p/2076927.html
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