Question

我有一个字符串的NSArray是URL。数组中的每个URL都指向与歌曲部分相关联的数据。我可以使用以下代码播放完整的歌曲，该歌曲将歌曲完全下载到单个文件，然后从该文件播放：

// Get file path to store song locally
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *filePath = [NSString stringWithFormat:@"%@/temp.mp3", [paths objectAtIndex:0]];

// Remove current temp file and create a new one
NSFileManager *fileManager = [NSFileManager defaultManager];
NSError *error;
if ([fileManager fileExistsAtPath:filePath]) [fileManager removeItemAtPath:filePath error:&error];
[fileManager createFileAtPath:filePath contents:nil attributes:nil];
NSFileHandle *fileHandle = [NSFileHandle fileHandleForWritingAtPath:filePath];

// Initialize loop variables
NSMutableData *songData = nil;
NSUInteger totalLength = 0;
NSString *localURLString = [NSString stringWithFormat:@"file://%@", [filePath stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding]];
NSURL *localURL = [NSURL URLWithString:localURLString];

for (NSString *stringURL in urls) {
    NSURL *url = [NSURL URLWithString:stringURL];
    songData = [NSMutableData dataWithContentsOfURL:url];
    totalLength += songData.length;
    [fileHandle writeData:songData];
    [fileHandle synchronizeFile];
}

[fileHandle closeFile];
self.player = [AVPlayer playerWithPlayerItem:[AVPlayerItem playerItemWithURL:localURL]];
[self.player play];

现在我试图让整首歌曲无缝播放而不先下载整个歌曲（所以基本上是流式播放，但不是从一个URL流式传输，我必须在流式传输时将歌曲从多个拼凑在一起）。< / p>

我有哪些选择？

更新1：

我尝试生成清单文件，编写文件时没有错误，而manifestString似乎格式正确，但播放器无法播放。

NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *manifestPath = [NSString stringWithFormat:@"%@/manifest.m3u8", [paths objectAtIndex:0]];
NSMutableString *manifestString = [[NSMutableString alloc] init];
[manifestString appendString:@"#EXTM3\n"];
for (NSString *stringURL in urls) {
    [manifestString appendFormat:@"%@\n", stringURL];
}
[manifestString appendString:@"#EXT-X-ENDLIST"];
NSError *err = nil;
[manifestString writeToFile:manifestPath atomically:YES encoding:NSUTF8StringEncoding error:&err];
if (err) {
    NSLog(@"error writing manifest: %@", err);
}
NSString *manifestURLString = [NSString stringWithFormat:@"file://%@", [filePath stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding]];
NSURL *manifestURL = [NSURL URLWithString:manifestURLString];
self.player = [AVPlayer playerWithPlayerItem:[AVPlayerItem playerItemWithURL:manifestURL]];
[self.player play];

Answer 1

由于您的目标是iOS，您是否考虑过使用HTTP直播（HLS）？ https://developer.apple.com/library/ios/documentation/networkinginternet/conceptual/streamingmediaguide/HTTPStreamingArchitecture/HTTPStreamingArchitecture.html

虽然它通常用于视频+音频，但您可以在服务器上创建一个仅音频清单文件，按顺序列出歌曲的每个片段，AVPlayer会自动为您逐个下载。< / p>

例如，我拍了一首歌（在一个名为sample.mp3的文件中）并将其分段以便在fLSmpeg中用于HLS：

ffmpeg -i sample.mp3 -acodec copy -map 0 -f segment -segment_time 5 -segment_list index.m3u8 segment%05d.mp3

这将获取输入文件（sample.mp3）并将其拆分为5秒段。它会吐出一个清单文件（在这种情况下为index.m3u8）：

#EXTM3U
#EXT-X-VERSION:3
#EXT-X-MEDIA-SEQUENCE:0
#EXT-X-ALLOW-CACHE:YES
#EXT-X-TARGETDURATION:6
#EXTINF:5.015511,
segment00000.mp3
#EXTINF:4.989389,
segment00001.mp3
#EXTINF:5.015511,
segment00002.mp3
#EXTINF:4.989389,
segment00003.mp3
#EXTINF:5.015511,
segment00004.mp3
#EXTINF:4.989378,
segment00005.mp3
#EXTINF:4.989389,
segment00006.mp3
#EXTINF:5.015511,
segment00007.mp3
#EXTINF:4.989389,
segment00008.mp3
#EXTINF:5.015511,
segment00009.mp3
#EXTINF:4.989389,
segment00010.mp3
#EXTINF:4.571433,
segment00011.mp3
#EXT-X-ENDLIST

如果您将清单的URL传递给AVPlayer，则可以完成剩下的工作。

同时下载和播放从多个URL拼凑在一起的歌曲

1 个答案: