场景
把多条mp3音频合并为一条保存并进行播放
解决方案
- 首先把全部音频路径生成为一个数组：
NSMutableArray * fileUrlArr = @[].mutableCopy;
[mp3NameArr enumerateObjectsUsingBlock:^(id _Nonnull obj, NSUInteger idx, BOOL * _Nonnull stop) {
NSString *mp3Name = [NSString stringWithFormat:@"%@",obj];
// mp3路径
NSString *audioFileURL = [[NSBundle mainBundle] pathForResource:mp3Name ofType:@"mp3"];
[fileUrlArr addObject:audioFileURL];
}];
- 通过以下方法合并音频，保存在一个随机文件中，因为文件如果已存在或者文件目录写入失败，会出现【AVAssetExportSessionStatusFailed】错误码
///合并音频
- (void) mergeAVAssetWithSourceURLs:(NSArray *)sourceURLsArr completed:(void (^)(NSString * outputFileUrlStr)) completed{
//创建音频轨道,并获取多个音频素材的轨道
AVMutableComposition *composition = [AVMutableComposition composition];
//音频插入的开始时间,用于记录每次添加音频文件的开始时间
__block CMTime beginTime = kCMTimeZero;
[sourceURLsArr enumerateObjectsUsingBlock:^(id _Nonnull audioFileURL, NSUInteger idx, BOOL * _Nonnull stop) {
//获取音频素材
AVURLAsset *audioAsset1 = [AVURLAsset assetWithURL:[NSURL fileURLWithPath:audioFileURL]];
//音频轨道
AVMutableCompositionTrack *audioTrack1 = [composition addMutableTrackWithMediaType:AVMediaTypeAudio preferredTrackID:0];
//获取音频素材轨道
AVAssetTrack *audioAssetTrack1 = [[audioAsset1 tracksWithMediaType:AVMediaTypeAudio] firstObject];
//音频合并- 插入音轨文件
[audioTrack1 insertTimeRange:CMTimeRangeMake(kCMTimeZero, audioAsset1.duration) ofTrack:audioAssetTrack1 atTime:beginTime error:nil];
// 记录尾部时间
beginTime = CMTimeAdd(beginTime, audioAsset1.duration);
}];
//导出合并后的音频文件
//音频文件目前只找到支持m4a 类型的
AVAssetExportSession *session = [[AVAssetExportSession alloc]initWithAsset:composition presetName:AVAssetExportPresetAppleM4A];
NSDateFormatter *formater = [[NSDateFormatter alloc] init];
[formater setDateFormat:@"yyyy-MM-dd-HH:mm:ss-SSS"];
NSString * timeFromDateStr = [formater stringFromDate:[NSDate date]];
NSString *outPutFilePath = [NSHomeDirectory() stringByAppendingFormat:@"/tmp/sound-%@.mp4", timeFromDateStr];
// 音频文件输出
session.outputURL = [NSURL fileURLWithPath:outPutFilePath];
session.outputFileType = AVFileTypeAppleM4A; //与上述的`present`相对应
session.shouldOptimizeForNetworkUse = YES; //优化网络
[session exportAsynchronouslyWithCompletionHandler:^{
if (session.status == AVAssetExportSessionStatusCompleted) {
NSLog(@"合并成功----%@", outPutFilePath);
if (completed) {
completed(outPutFilePath);
}
} else {
// 其他情况, 具体请看这里`AVAssetExportSessionStatus`.
NSLog(@"合并失败----%ld", (long)session.status);
if (completed) {
completed(nil);
}
}
}];
}
- 输出合并音频
// 合并音频文件生成新的音频
[self mergeAVAssetWithSourceURLs:musicArr completed:^(NSString *outputFileUrlStr) {
if (!outputFileUrlStr) {
NSLog(@"声音生成失败!");
return;
}
self.audioPlayer = [[AVAudioPlayer alloc] initWithContentsOfURL:[NSURL fileURLWithPath:outputFileUrlStr] error:nil];
[self.audioPlayer play];
}];
参考：
https://www.cxyzjd.com/article/ismilesky/52780349
https://www.jianshu.com/p/3e357e3129b8
http://www.cocoachina.com/articles/17624
