iOS开发- 音频截取

来源：互联网发布：买二手物品的软件编辑：程序博客网时间：2024/05/16 07:42

#pragma mark - 截取音频方法- (void)captureSongAction{    CocoaSecurityResult * result = [CocoaSecurity md5:[[NSDate date] description]];    // 创建音频文件    NSArray *dirs = NSSearchPathForDirectoriesInDomains(NSDocumentationDirectory, NSUserDomainMask,YES);    NSString *documentsDirectoryPath = [dirs objectAtIndex:0];    NSString *filePath = [documentsDirectoryPath stringByAppendingPathComponent:@"CaptureMusic"];    if (![[NSFileManager defaultManager] fileExistsAtPath:filePath]) {        [[NSFileManager defaultManager] createDirectoryAtPath:filePath withIntermediateDirectories:YES attributes:nil error:nil];    }        NSString *tempMusicPath = [NSString stringWithFormat:@"%@/%@.m4a",filePath, result.hex];        NSArray *compatiblePresets = [AVAssetExportSession exportPresetsCompatibleWithAsset:self.asset];    if ([compatiblePresets containsObject:AVAssetExportPresetMediumQuality]) {                AVAssetExportSession *exportSession = [[AVAssetExportSession alloc]                                               initWithAsset:self.asset presetName:AVAssetExportPresetAppleM4A];        // Implementation continues.                CMTime startTime = CMTimeMake(self.startTime, 1);        CMTime stopTime = CMTimeMake(self.startTime+self.playTime, 1);        CMTimeRange exportTimeRange = CMTimeRangeFromTimeToTime(startTime, stopTime);                        NSURL *furl = [NSURL fileURLWithPath:tempMusicPath];        exportSession.outputURL = furl;        exportSession.outputFileType = AVFileTypeAppleM4A;        exportSession.timeRange = exportTimeRange; // 截取时间        [exportSession exportAsynchronouslyWithCompletionHandler:^{                        switch ([exportSession status]) {                case AVAssetExportSessionStatusFailed:                                        NSLog(@"Export failed: %@", [[exportSession error] localizedDescription]);                    break;                case AVAssetExportSessionStatusCancelled:                                        NSLog(@"Export canceled");                    break;                default:                    [self addCertainAlertViewWithTitle:LocalizedString(@"AlertViewTitleSysPrompt") Message:@"截取成功"];                    NSLog(@"保存成功");            }        }];            }   }

因为iOS的输出格式不支持.mp3,只能设置为.m4a的音频文件.

AVAssetExportSession支持导出的文件类型如下所示:

<__NSArrayI 0x158c0d60>(

com.apple.quicktime-movie,

com.apple.m4a-audio,

public.mpeg-4,

com.apple.m4v-video,

public.3gpp,

org.3gpp.adaptive-multi-rate-audio,

com.microsoft.waveform-audio,

public.aiff-audio,

public.aifc-audio,

com.apple.coreaudio-format

)

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