【IOS开发】多媒体操作

1、录音功能

1）引入两个类库

2）

//引入头文件
#import <AVFoundation/AVFoundation.h>
#import <CoreAudio/CoreAudioTypes.h>

//在.h文件声明变量
AVAudioRecorder *audioRecorder;

//在.m文件
AVAudioSession *audioSession = [AVAudioSession sharedInstance];
[audioSession setCategory:AVAudioSessionCategoryPlayAndRecord error:nil];
[audioSession setActive:YES error:nil];
//此变量音频会话用来设置录音模式
/****
AVAudioSessionCategorySoloAmbient
这个类别非常像AVAudioSessionCategoryAmbient类别，除了会停止其他程序的音频回放，比如iPod程序。当设备被设置为静音模式，你的音频回放将会停止。

AVAudioSessionCategoryRecord
这会停止其他应用的声音（比如iPod）并让你的应用也不能初始化音频回放（比如AVAudioPlayer）。在这种模式下，你只能进行录音。使用这个类别，调用AVAudioPlayer的prepareToPlay会返回YES，但是调用play方法将返回NO。主UI界面会照常工作。这时，即使你的设备屏幕被用户锁定了，应用的录音仍会继续。

AVAudioSessionCategoryPlayback
这个类别会静止其他应用的音频回放（比如iPod应用的音频回放）。你可以使用AVAudioPlayer的prepareToPlay和play方法，在你的应用中播放声音。主UI界面会照常工作。这时，即使屏幕被锁定或者设备为静音模式，音频回放都会继续。

AVAudioSessionCategoryPlayAndRecord
这个类别允许你的应用中同时进行声音的播放和录制。当你的声音录制或播放开始后，其他应用的声音播放将会停止。主UI界面会照常工作。这时，即使屏幕被锁定或者设备为静音模式，音频回放和录制都会继续。

AVAudioSessionCategoryAudioProcessing
这个类别用于应用中进行音频处理的情形，而不是音频回放或录制。设置了这种模式，你在应用中就不能播放和录制任何声音。调用AVAPlayer的prepareToPlay和play方法都将返回NO。其他应用的音频回放，比如iPod，也会在此模式下停止。

AVAudioSessionCategoryAmbient
这个类别不会停止其他应用的声音，相反，它允许你的音频播放于其他应用的声音之上，比如iPod。你的应用的主UI县城会工作正常。调用AVAPlayer的prepareToPlay和play方法都将返回YES。当用户锁屏时，你的应用将停止所有正在回放的音频。仅当你的应用是唯一播放该音频文件的应用时，静音模式将停止你程序的音频回放。如果正当iPod播放一手歌时，你开始播放音频，将设备设为静音模式并不能停止你的音频回放。
****/
//创建音频文件的保存路径
NSFileManager *fileManager = [NSFileManager defaultManager];
    NSString *recordGroupPath = [NSHomeDirectory() stringByAppendingString:[NSString stringWithFormat:@"/Documents/record"]];
    groupPath = [recordGroupPath retain];
    if (![fileManager fileExistsAtPath:recordGroupPath]) {
        NSLog(@"没有此路径");
        [fileManager createDirectoryAtPath:recordGroupPath withIntermediateDirectories:YES attributes:nil error:nil];
    }

//根据当前时间给音频文件起名字，后缀名是caf
    NSDateFormatter *dateFormatter = [[[NSDateFormatter alloc] init] autorelease];
    [dateFormatter setDateFormat:@"HHmmss"];
    NSString *recordName = [NSString stringWithFormat:@"%@.caf", [dateFormatter stringFromDate:[NSDate date]]];
    NSString *recordPath = [recordGroupPath stringByAppendingFormat:@"/%@", recordName];
    NSURL *recordURL = [[NSURL alloc] initWithString:recordPath];
    //一些设置
    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];
    NSLog(@"recodrdURL = %@, recordSetting = %@",recordURL,recordSetting);
//创建实例，参数recordURL是刚刚创建的音频文件的路径
 audioRecorder = [[AVAudioRecorder alloc] initWithURL:recordURL settings:recordSetting error:nil];
    [recordURL release], recordURL = nil;
    [recordSetting release], recordSetting = nil;
    if ([audioRecorder prepareToRecord]) {
        [audioRecorder record];
    }

//结束录音
[audioRecorder stop];

//播放录音
//继承代理AVAudioPlayerDelegate
//.h文件声明
AVAudioPlayer *audioPlayer;
//.m文件
NSURL *fileURL = [[NSURL alloc] initFileURLWithPath:recordPath];
    NSLog(@"fileURL = %@", fileURL);
    audioPlayer = [[AVAudioPlayer alloc] initWithContentsOfURL:fileURL error:nil];
    [audioPlayer setDelegate:self];
    NSLog(@"持续时间：%f", audioPlayer.duration);
    if ([audioPlayer prepareToPlay]) {
        [audioPlayer play];
    }
    [fileURL release], fileURL = nil;

/* audioPlayerDidFinishPlaying:successfully: is called when a sound has finished playing. This method is NOT called if the player is stopped due to an interruption. */
- (void)audioPlayerDidFinishPlaying:(AVAudioPlayer *)player successfully:(BOOL)flag
{
  NSLog(@"播放完毕！");
}

可以给录音界面加一个计时器，见效果图

之前见过这种效果觉得很神奇，这怎么做的呢，后来发现这只是一种字体！太坑爹了！

在.h文件

NSTimer *timer;
UILabel *timeLabel;
NSDate *beginDate;

.m文件

beginDate = [[NSDate date] retain];
    timer = [NSTimer scheduledTimerWithTimeInterval:(1.0) target:self selector:@selector(onTimer) userInfo:nil repeats:YES];
    timeLabel = [[UILabel alloc] initWithFrame:CGRectMake(100, 100, 320 - 200, 100)];
    [timeLabel setFont:[UIFont fontWithName:@"DBLCDTempBlack" size:24]];
    [timeLabel setBackgroundColor:[UIColor clearColor]];
    [timeLabel setTextAlignment:UITextAlignmentCenter];
    [timeLabel setTextColor:[UIColor whiteColor]];
    [timeLabel setText:@"00:00:00"];
    [self.view addSubview:timeLabel];

//NSTimer调用方法
- (void)onTimer
{
    NSDate *nowDate = [NSDate date];
    NSCalendar *chineseClendar = [[NSCalendar alloc ] initWithCalendarIdentifier:NSGregorianCalendar];
    NSUInteger unitFlags =  NSHourCalendarUnit | NSMinuteCalendarUnit | NSSecondCalendarUnit;
    NSDateComponents *dateComponent = [chineseClendar components:unitFlags fromDate:beginDate toDate:nowDate options:0];
    NSLog(@"%d:%d:%d", dateComponent.hour, dateComponent.minute, dateComponent.second);
    timeLabel.text = [NSString stringWithFormat:@"%0.2d:%0.2d:%0.2d", dateComponent.hour, dateComponent.minute, dateComponent.second];
    [chineseClendar release], chineseClendar = nil;
}

在使用了NSTimer之后会发现dealloc方法不回被调用了，可以在- (void)viewDidDisappear:(BOOL)animated方法中释放内存。

 

2、拍照和录像

这两者放一块是因为两者都用到同一个类UIImagePickerController，操作非常类似

//继承代理UIImagePickerControllerDelegate

//.h文件声明

UIImagePickerController *photoPicker;
 UIImagePickerController *videoPicker;

//.m文件

//拍照事件触发

UIImagePickerControllerSourceType sourceType = UIImagePickerControllerSourceTypeCamera;
    if (![UIImagePickerController isSourceTypeAvailable:UIImagePickerControllerSourceTypeCamera])
    {
        sourceType = UIImagePickerControllerSourceTypePhotoLibrary;
    }
    photoPicker = [[UIImagePickerController alloc] init];
    photoPicker.delegate = self;
//    photoPicker.cameraCaptureMode = UIImagePickerControllerCameraCaptureModePhoto;

//有人说在iPad中用UIImagePickerController要用UIPopOverController，最先我也用了，后来我发现不用设置photoPicer的cameraCaptureMode属性，其实可以不用UIPopOverController，这样可以使拍照界面全屏，比用UIPopOverController效果好多了！
    photoPicker.allowsEditing = YES;
    photoPicker.sourceType = sourceType;
    [self presentViewController:photoPicker animated:YES completion:nil];

//摄像事件触发

UIImagePickerControllerSourceType sourceType = UIImagePickerControllerSourceTypeCamera;
    if (![UIImagePickerController isSourceTypeAvailable:UIImagePickerControllerSourceTypeCamera])
    {
        sourceType = UIImagePickerControllerSourceTypePhotoLibrary;
    }
    videoPicker = [[UIImagePickerController alloc] init];
    videoPicker.mediaTypes =[NSArray arrayWithObjects:(NSString*)kUTTypeMovie,  nil];
    videoPicker.delegate = self;
//    photoPicker.cameraCaptureMode = UIImagePickerControllerCameraCaptureModeVideo;
    videoPicker.allowsEditing = YES;
    videoPicker.sourceType = sourceType;
    [self presentViewController:videoPicker animated:YES completion:nil];
//与上边的拍照事件触发的方法对比，多了一个mediaTypes属性设置，这个属性是一个数组，添加pickerController支持的模式，默认支持拍照，但是也可以自己设置，此时你设置成支持什么模式，它就支持什么模式，如果我这样设置    videoPicker.mediaTypes =[NSArray arrayWithObjects:(NSString*)kUTTypeMovie, (NSString *)kUTTypeImage, nil];那此pickerController就支持拍照摄像双模式的转换，非常方便，所以，若不是项目需要，我就把拍照和摄像功能写成一个UIImagePickerController

 

代理

#pragma mark - UIImagePickerController Delegate

- (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info
{
    [picker dismissModalViewControllerAnimated:YES];
    NSFileManager *fileManager = [NSFileManager defaultManager];

//之前我并没有设置cameraCaptureMode属性，相反，设置了可能回引起程序崩溃，相信有很多人是在此引起程序崩溃后查原因发现有人说要用到UIPopOverController的，因为，我也是这样、、、但是不用设置此属性，系统回自动判断UIImagePickerController的属性的
    if (picker.cameraCaptureMode == UIImagePickerControllerCameraCaptureModePhoto) {
        //拍照
        NSString *imageGroupPath = [NSHomeDirectory() stringByAppendingString:[NSString stringWithFormat:@"/Documents/photo"]];
        if (![fileManager fileExistsAtPath:imageGroupPath]) {
            NSLog(@"没有此路径");
            [fileManager createDirectoryAtPath:imageGroupPath withIntermediateDirectories:YES attributes:nil error:nil];
        }

        UIImage *image = [info objectForKey:UIImagePickerControllerOriginalImage];
        NSData *imageData;
        if (UIImagePNGRepresentation(image) == nil) {
            imageData = UIImageJPEGRepresentation(image, 1);
            NSLog(@"jpeg");
        }else{
            imageData = UIImagePNGRepresentation(image);
            NSLog(@"png");
        }

        NSDateFormatter *dateFormatter = [[[NSDateFormatter alloc] init] autorelease];
        [dateFormatter setDateFormat:@"yyyyMMddHHmmss"];
        NSString *imageName = [NSString stringWithFormat:@"%@.png", [dateFormatter stringFromDate:[NSDate date]]];
        NSString *imagePath = [imageGroupPath stringByAppendingFormat:@"/%@", imageName];
        if (imageData) {
            [imageData writeToFile:imagePath atomically:YES];
            NSLog(@"保存成功！");
        }else{
            NSLog(@"数据有误！");
        }

        [tableview reloadData]; //更新下tableview或进行其他操作
    }else{
        //视频
        NSString *videoGroupPath = [NSHomeDirectory() stringByAppendingString:[NSString stringWithFormat:@"/Documents/video"]];
        if (![fileManager fileExistsAtPath:videoGroupPath]) {
            NSLog(@"没有此路径");
            [fileManager createDirectoryAtPath:videoGroupPath withIntermediateDirectories:YES attributes:nil error:nil];
        }
        NSDateFormatter *dateFormatter = [[[NSDateFormatter alloc] init] autorelease];
        [dateFormatter setDateFormat:@"yyyyMMddHHmmss"];
        NSString *videoName = [NSString stringWithFormat:@"%@.mov", [dateFormatter stringFromDate:[NSDate date]]];
        NSURL *videoURL = [info objectForKey:UIImagePickerControllerMediaURL];
        NSString *newFilePath = [videoGroupPath stringByAppendingFormat:@"/%@", videoName];
//        NSLog(@"newFilePath = %@", newFilePath);
        NSData *videoData = [NSData dataWithContentsOfURL:videoURL];
        if (videoData) {
            [videoData writeToFile:newFilePath atomically:YES];
            NSLog(@"保存成功！");
        }else{
            NSLog(@"数据有误！");
        }

        [tableview reloadData];
    }
    [picker release], picker = nil;
}