[IOS development-118] AVFoundation framework: AudioServices... sound effects, AVAudioPlayer music, AVAudioRecord recording,

[IOS development-118] AVFoundation framework: AudioServices... sound effects, AVAudioPlayer music, AVAudioRecord recording,

(1) sound playback: the Core code mainly creates a player and then plays the video.

# Import "WPSound. h "# import <AVFoundation/AVFoundation. h> @ implementation WPSoundstatic NSMutableDictionary * _ soundIDDict; + (void) initialize {_ soundIDDict = [NSMutableDictionary dictionary];} // cannot be loaded with laziness, because of the time class method used by the user, you need to set/-(NSMutableDictionary *) soundIDDict {// if (_ soundIDDict = nil) in the class initialization above) {// _ soundIDDict = [NSMutableDictionary dictionary]; //} // return _ soundIDDict; //} + (void) soundPlay :( NSString *) fileN Ame {if (! FileName) return; // retrieve soundID SystemSoundID soundID = [_ soundIDDict [fileName] unsignedIntValue]; if (! SoundID) {NSURL * url = [[NSBundle mainBundle] URLForResource: fileName withExtension: nil]; if (! Url) return; encode (_ bridge CFURLRef) url, & soundID); // put it into the dictionary _ soundIDDict [fileName] =@ (soundID);} AudioServicesPlaySystemSound (soundID );} + (void) soundDispose :( NSString *) fileName {if (fileName) return; SystemSoundID soundID = [_ soundIDDict [fileName] unsignedIntValue]; if (! SoundID) return; AudioServicesDisposeSystemSoundID (soundID); // remove [_ soundIDDict removeObjectForKey: fileName] from the dictionary;} @ end

(2) music playback and core code. Note that the created player must be a global variable.

# Import "MusicTool. h "@ implementation MusicToolstatic NSMutableDictionary * _ audioPlayerDict; static AVAudioPlayer * _ audioPlayer; + (void) initialize {_ audioPlayerDict = [NSMutableDictionary dictionary]; // set the session type AVAudioSession * session = [AVAudioSession sharedInstance]; [session setCategory: AVAudioSessionCategorySoloAmbient error: nil]; [session setActive: YES error: nil];} + (AVAudioPlayer *) musicPlay :( NSString *) FileName {if (! FileName) return nil; // retrieve the player AVAudioPlayer * audioPlayer = _ audioPlayerDict [fileName]; if (! AudioPlayer) {NSURL * url = [[NSBundle mainBundle] URLForResource: fileName withExtension: nil]; if (! Url) return nil; // create audioPlayer AVAudioPlayer * audioPlayer = [[AVAudioPlayer alloc] initWithContentsOfURL: url error: NULL]; _ audioPlayer = audioPlayer; [_ audioPlayer prepareToPlay]; _ audioPlayer. enableRate = YES; // set the playing speed below. You can test the playback speed with // _ audioPlayer. rate = 10; // _ audioPlayerDict [fileName] = audioPlayer;} if (! _ AudioPlayer. isPlaying) {[_ audioPlayer play];} return _ audioPlayer;} + (void) musicPause :( NSString *) fileName {if (! FileName) return; AVAudioPlayer * audioPlayer = _ audioPlayerDict [fileName]; if (audioPlayer. isPlaying) {[audioPlayer pause] ;}+ (void) musicStop :( NSString *) fileName {if (! FileName) return; AVAudioPlayer * audioPlayer = _ audioPlayerDict [fileName]; if (audioPlayer. isPlaying) {[audioPlayer stop]; [_ audioPlayerDict removeObjectForKey: fileName] ;}+ (AVAudioPlayer *) currentPlayingAudioPlayer {for (NSString * fileName in _ audioPlayerDict) {AVAudioPlayer * audioPlayer = _ audioPlayerDict [fileName]; if (audioPlayer. isPlaying) {return audioPlayer;} return nil;} @ end

(3) Recording and core code.

# Import "ViewController. h "# import <AVFoundation/AVFoundation. h> @ interface ViewController () @ property (nonatomic, strong) AVAudioRecorder * recorder; @ property (nonatomic, strong) CADisplayLink * link; @ property (nonatomic, assign) float silentDuration; -(IBAction) recordStart :( id) sender;-(IBAction) recordStop :( id) sender; @ end @ implementation ViewController-(CADisplayLink *) link {if (_ link = nil) {_ link = [CADisplayLink displayLinkWithTarget: self selector: @ selector (update)];} return _ link;}-(void) update {// update the recorded value [self. recorder updateMeters]; // obtain the average beam float power = [self. recorder averagePowerForChannel: 0]; if (power <-30) {self. silentDuration + = self. link. duration; if (self. silentDuration> = 2) {[self. recorder stop]; [self. link invalidate]; self. link = nil ;}} else {self. silentDuration = 0 ;}}-(void) viewDidLoad {[super viewDidLoad]; // Do any additional setup after loading the view, typically from a nib .} -(void) didReceiveMemoryWarning {[super didreceivemorywarning]; // Dispose of any resources that can be recreated .} -(IBAction) recordStart :( id) sender {NSString * path = [[NSSearchPathForDirectoriesInDomains (NSDocumentationDirectory, NSUserDomainMask, YES) lastObject] stringByAppendingPathComponent: @ "test. caf "]; NSURL * url = [NSURL fileURLWithPath: path]; NSMutableDictionary * setting = [NSMutableDictionary dictionary]; // audio format setting [AVFormatIDKey] = @ (kAudioFormatAppleIMA4 ); // audio sampling rate setting [AVSampleRateKey] = @ (8000.0); // number of audio channels setting [AVNumberOfChannelsKey] = @ (1 ); // linear audio bit depth setting [AVLinearPCMBitDepthKey] = @ (8); AVAudioRecorder * recorder = [[AVAudioRecorder alloc] initWithURL: url settings: setting error: nil]; // allow decibel recorder measurement. meteringEnabled = YES; // buffer [recorder prepareToRecord]; // recording [recorder record]; self. recorder = recorder; // enable the timer self. silentDuration = 0; [self. link addToRunLoop: [nsunloop mainRunLoop] forMode: NSDefaultRunLoopMode];}-(IBAction) recordStop :( id) sender {[self. link invalidate]; self. link = nil; [self. recorder stop];} @ end

(3) play music in the background and set three places.

-- Set in AppDelegate. m

- (void)applicationDidEnterBackground:(UIApplication *)application {    [application beginBackgroundTaskWithExpirationHandler:nil];}

-- Set in info. plist

-- Set the audio session type in the Program (which can be omitted)

+ (Void) initialize {_ audioPlayerDict = [NSMutableDictionary dictionary]; // sets the session type AVAudioSession * session = [AVAudioSession sharedInstance]; [session setCategory: callback error: nil]; [session setActive: YES error: nil];}