我有自己的MediaDataSource：
class MyDataSource extends MediaDataSource {
private static final String TAG = "MyDataSource";
private HttpURLConnection connection;
private BufferedInputStream inputStream;
MyDataSource(@NonNull URL streamURL) throws Throwable {
this.connection = (HttpURLConnection) streamURL.openConnection();
this.connection.setRequestMethod("GET");
this.connection.addRequestProperty("Icy-Metadata", "0");
this.connection.connect();
int responseCode = this.connection.getResponseCode();
if (responseCode != 200)
throw new IOException("http response code " + responseCode);
for (Map.Entry<String, List<String>> header: this.connection.getHeaderFields().entrySet()) {
for (String headerValue : header.getValue())
Log.v(TAG, "responseHeader(" + header.getKey() + ") = \"" + headerValue + "\"");
}
this.inputStream = new BufferedInputStream(connection.getInputStream());
}
@Override
public long getSize() {
return -1;
}
@Override
public int readAt(long position, @NonNull byte[] buffer, int offset, int size) throws IOException {
int bytesRead;
int bytesReadTotal = 0;
do {
bytesRead = this.inputStream.read(buffer, offset + bytesReadTotal, size - bytesReadTotal);
bytesReadTotal += bytesRead;
} while(bytesRead != 0 && bytesReadTotal < size);
return bytesReadTotal;
}
@Override
public void close() {
try {
if (inputStream != null) {
inputStream.close();
inputStream = null;
}
if (connection != null) {
connection.disconnect();
connection = null;
}
} catch(IOException e) {
Log.e(TAG, "close", e);
}
}
}
当我尝试播放MP3信息流（例如A.0.0.00Radio）时：
MyDataSource dataSource = new MyDataSource(new URL("http://streaming.shoutcast.com/80sPlanet"));
MediaExtractor mediaExtractor = new MediaExtractor();
mediaExtractor.setDataSource();
MediaFormat mediaFormat = mediaExtractor.getTrackFormat(0);
String mime = mediaFormat.getString(MediaFormat.KEY_MIME);
Log.v("Player", "mime: " + mime);
mediaExtractor.selectTrack(0);
MediaCodec mediaCodec = MediaCodec.createDecoderByType(mime);
mediaCodec.configure(this.mediaFormat, null, null, 0);
int sampleRate = mediaFormat.getInteger(MediaFormat.KEY_SAMPLE_RATE);
AudioTrack audioTrack = new AudioTrack(
AudioManager.STREAM_MUSIC,
sampleRate,
AudioFormat.CHANNEL_OUT_STEREO,
AudioFormat.ENCODING_PCM_16BIT,
AudioTrack.getMinBufferSize(sampleRate, AudioFormat.CHANNEL_OUT_STEREO, AudioFormat.ENCODING_PCM_16BIT),
AudioTrack.MODE_STREAM);
mediaCodec.setCallback(new MyCodecCallback());
mediaCodec.start();
audioTrack.play();
我看到以下Logcat trace：
07-24 18:11:49.958 7408-7671/com.sample.sandbox V/MyDataSource: responseHeader(null) = "HTTP/1.1 200 OK"
07-24 18:11:49.958 7408-7671/com.sample.sandbox V/MyDataSource: responseHeader(Access-Control-Allow-Headers) = "Origin, Accept, X-Requested-With, Content-Type"
07-24 18:11:49.958 7408-7671/com.sample.sandbox V/MyDataSource: responseHeader(Access-Control-Allow-Methods) = "GET, OPTIONS, HEAD"
07-24 18:11:49.958 7408-7671/com.sample.sandbox V/MyDataSource: responseHeader(Access-Control-Allow-Origin) = "*"
07-24 18:11:49.958 7408-7671/com.sample.sandbox V/MyDataSource: responseHeader(Cache-Control) = "no-cache, no-store"
07-24 18:11:49.958 7408-7671/com.sample.sandbox V/MyDataSource: responseHeader(Connection) = "close"
07-24 18:11:49.958 7408-7671/com.sample.sandbox V/MyDataSource: responseHeader(Content-Type) = "audio/mpeg"
07-24 18:11:49.958 7408-7671/com.sample.sandbox V/MyDataSource: responseHeader(Date) = "Mon, 24 Jul 2017 18:11:59 GMT"
07-24 18:11:49.959 7408-7671/com.sample.sandbox V/MyDataSource: responseHeader(Expires) = "Mon, 26 Jul 1997 05:00:00 GMT"
07-24 18:11:49.959 7408-7671/com.sample.sandbox V/MyDataSource: responseHeader(icy-br) = "128"
07-24 18:11:49.959 7408-7671/com.sample.sandbox V/MyDataSource: responseHeader(icy-genre) = "Decades,80s"
07-24 18:11:49.959 7408-7671/com.sample.sandbox V/MyDataSource: responseHeader(icy-name) = "A.0.0.00Radio:All 80s All The Time"
07-24 18:11:49.959 7408-7671/com.sample.sandbox V/MyDataSource: responseHeader(icy-notice1) = "<BR>This stream requires <a href="http://www.winamp.com">Winamp</a><BR>"
07-24 18:11:49.959 7408-7671/com.sample.sandbox V/MyDataSource: responseHeader(icy-notice2) = "SHOUTcast DNAS/posix(linux x64) v2.5.1.725<BR>"
07-24 18:11:49.959 7408-7671/com.sample.sandbox V/MyDataSource: responseHeader(icy-pub) = "1"
07-24 18:11:49.959 7408-7671/com.sample.sandbox V/MyDataSource: responseHeader(icy-sr) = "44100"
07-24 18:11:49.959 7408-7671/com.sample.sandbox V/MyDataSource: responseHeader(icy-url) = "http://a.0.00radio.com/80s/"
07-24 18:11:49.959 7408-7671/com.sample.sandbox V/MyDataSource: responseHeader(Pragma) = "no-cache"
07-24 18:11:49.959 7408-7671/com.sample.sandbox V/MyDataSource: responseHeader(Server) = "Icecast 2.3.3-kh8"
07-24 18:11:49.959 7408-7671/com.sample.sandbox V/MyDataSource: responseHeader(X-Android-Received-Millis) = "1500919909958"
07-24 18:11:49.959 7408-7671/com.sample.sandbox V/MyDataSource: responseHeader(X-Android-Response-Source) = "NETWORK 200"
07-24 18:11:49.959 7408-7671/com.sample.sandbox V/MyDataSource: responseHeader(X-Android-Selected-Protocol) = "http/1.1"
07-24 18:11:49.959 7408-7671/com.sample.sandbox V/MyDataSource: responseHeader(X-Android-Sent-Millis) = "1500919909816"
07-24 18:11:49.961 7408-7671/com.sample.sandbox E/WVMExtractor: Failed to open libwvm.so: dlopen failed: library "libwvm.so" not found
07-24 18:11:49.962 7408-7671/com.sample.sandbox V/Player: mime: audio/mpeg
07-24 18:11:49.964 7408-7681/com.sample.sandbox I/OMXClient: Using client-side OMX mux.
07-24 18:11:50.170 7408-7681/com.sample.sandbox I/MediaCodec: MediaCodec will operate in async mode
[...]
似乎一切正常（流正在通过设备播放）
但是，如果我尝试打开AAC信息流（例如COOLfahrenheit 93）：
MyDataSource dataSource = new MyDataSource(new URL("http://111.223.51.8:8005"));
[...]
MediaExtractor发疯：
07-24 18:38:43.863 32284-32690/com.sample.sandbox V/MyDataSource: responseHeader(null) = "HTTP/1.0 200 OK"
07-24 18:38:43.863 32284-32690/com.sample.sandbox V/MyDataSource: responseHeader(content-type) = "audio/aacp"
07-24 18:38:43.863 32284-32690/com.sample.sandbox V/MyDataSource: responseHeader(icy-br) = "128"
07-24 18:38:43.863 32284-32690/com.sample.sandbox V/MyDataSource: responseHeader(icy-genre) = "Easy Listening, Pop"
07-24 18:38:43.863 32284-32690/com.sample.sandbox V/MyDataSource: responseHeader(icy-name) = "COOLfahrenheit 93 - (4)"
07-24 18:38:43.863 32284-32690/com.sample.sandbox V/MyDataSource: responseHeader(icy-notice1) = "<BR>This stream requires <a href="http://www.winamp.com">Winamp</a><BR>"
07-24 18:38:43.863 32284-32690/com.sample.sandbox V/MyDataSource: responseHeader(icy-notice2) = "SHOUTcast DNAS/posix(linux x64) v2.4.7.256<BR>"
07-24 18:38:43.863 32284-32690/com.sample.sandbox V/MyDataSource: responseHeader(icy-pub) = "1"
07-24 18:38:43.863 32284-32690/com.sample.sandbox V/MyDataSource: responseHeader(icy-url) = "http://www.coolism.net"
07-24 18:38:43.863 32284-32690/com.sample.sandbox V/MyDataSource: responseHeader(X-Android-Received-Millis) = "1500921523862"
07-24 18:38:43.863 32284-32690/com.sample.sandbox V/MyDataSource: responseHeader(X-Android-Response-Source) = "NETWORK 200"
07-24 18:38:43.863 32284-32690/com.sample.sandbox V/MyDataSource: responseHeader(X-Android-Selected-Protocol) = "http/1.0"
07-24 18:38:43.863 32284-32690/com.sample.sandbox V/MyDataSource: responseHeader(X-Android-Sent-Millis) = "1500921523387"
07-24 18:38:43.863 32284-32690/com.sample.sandbox V/MyDataSource: responseHeader(X-Clacks-Overhead) = "GNU Terry Pratchett"
07-24 18:38:45.424 32284-32690/com.sample.sandbox E/WVMExtractor: Failed to open libwvm.so: dlopen failed: library "libwvm.so" not found
07-24 18:38:45.425 32284-32690/com.sample.sandbox E/PlayerThread: error
java.io.IOException: Failed to instantiate extractor.
at android.media.MediaExtractor.setDataSource(Native Method)
at com.sample.sandbox.Player.open(Player.java:204)
at com.sample.sandbox.Player.<init>(Player.java:231)
at com.sample.sandbox.PlayerThread.run(PlayerThread.java:28)
答案 0 :(得分：0)
我的主要错误是忽略position方法的MediaDataSource::readAt()参数
事实证明，MediaExtractor执行了很多跳过文件（向前和向后！ - 当你流式传输HLS时，这非常烦人）。
我注意到这些跳过（及其'范围）的数量取决于内容类型以及特定的编解码器。我在这个问题中的主要观点是“MediaExtractor不理解aacp”，因为AAC编解码器强烈要求跳过，但MP3编解码器却没有。