如何在ios开发中从mp3文件中提取元数据
我正在使用云存储的ios音乐播放器。
我需要提取标题，艺术家，艺术品等音乐信息。
我有一个叫做playit的动作，可以播放和暂停mp3文件。 它还应该使用与mp3文件关联的metadtaa来填充一些UILables和UIImage。 问题是我无法从超过25个不同的mp3文件中提取元数据。 这是我的代码：
文件的URL是正确的，因为音频播放器能够找到并播放它，但我不知道为什么avmetadataitem无法获取元数据。
- (IBAction)playIt:(id)sender {
AVAudioPlayer *audioPlayer;
AVAsset *assest;
NSString * applicationPath = [[NSBundle mainBundle] resourcePath];
NSString *secondParentPath = [applicationPath stringByDeletingLastPathComponent];
NSString *soundFilePath = [[secondParentPath stringByAppendingPathComponent:@"fisal1407"] stringByAppendingPathComponent:[musicFiles objectForKey:@"show_id"] ];
NSURL *fileURL = [NSURL URLWithString:[soundFilePath stringByAddingPercentEscapesUsingEncoding: NSUTF8StringEncoding]];
assest = [AVURLAsset URLAssetWithURL:fileURL options:nil];
NSArray *metadata = [assest commonMetadata];
for (NSString *format in metadata) {
for (AVMetadataItem *item in [assest metadataForFormat:format]) {
if ([[item commonKey] isEqualToString:@"title"]) {
filename.text = (NSString *)[item value];
NSLog(@" title : %@", (NSString *)[item value]);
}
if ([[item commonKey] isEqualToString:@"artist"]) {
show_id.text = (NSString *)[item value];
}
if ([[item commonKey] isEqualToString:@"albumName"]) {
// _albumName = (NSString *)[item value];
}
if ([[item commonKey] isEqualToString:@"artwork"]) {
NSData *data = [(NSDictionary *)[item value] objectForKey:@"data"];
UIImage *img = [UIImage imageWithData:data] ;
imageView.image = img;
continue;
}
}
}
if (audioPlayer == nil) {
audioPlayer = [[AVAudioPlayer alloc] initWithContentsOfURL:fileURL error:&error];
audioPlayer.numberOfLoops = -1;
[audioPlayer play];
[sender setImage:[UIImage imageNamed:@"player_044.gif"] forState:UIControlStateNormal];
}
else
{
if (audioPlayer.isPlaying)
{
[sender setImage:[UIImage imageNamed:@"player_04.gif"] forState:UIControlStateNormal];
[audioPlayer pause];
} else {
[sender setImage:[UIImage imageNamed:@"player_044.gif"] forState:UIControlStateNormal];
[audioPlayer play];
}
}
}
尝试
for (NSString *format in [asset availableMetadataFormats])
代替
NSArray *metadata = [assest commonMetadata];
for (NSString *format in metadata) {
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