Not able to get getDuration() for AAC file using ExoPlayer

问题

I have been trying to stream a URL using ExoPlayer. The URLs:

STREAM_URL_1 = "http://storage.googleapis.com/exoplayer-test-media-0/play.mp3"

STREAM_URL_2 = "https://s3-ap-southeast-1.amazonaws.com/ok.talk.channels/zakirkhan/Zakir+khan+-+when+my+father+took+my+gf%27s+call.aac"

Both URLs play but I am not able to get the getDuration() for STREAM_URL_2 which is an .aac file. The .mp3 works.

The following is how I do it. How do I get the getDuration() for the 2nd URL. Even seekTo() doesn't work if getDuration() doesn't work.

What change should I make? Do I need to change any Extractor?

player = ExoPlayer.Factory.newInstance(RENDERER_COUNT, MIN_BUFFER_MS, MIN_RE_BUFFER_MS);
playerControl = new PlayerControl(player);
Allocator allocator = new DefaultAllocator(BUFFER_SEGMENT_SIZE);

private static final String STREAM_URL = "http://storage.googleapis.com/exoplayer-test-media-0/play.mp3";
uri = Uri.parse(STREAM_URL);

// Build the video and audio renderers.
DefaultBandwidthMeter bandwidthMeter = new DefaultBandwidthMeter(player.getMainHandler(),
    null);
String userAgent = Util.getUserAgent(this, "MyMediaPlayer");
DataSource dataSource = new DefaultUriDataSource(context, bandwidthMeter, userAgent, true);
ExtractorSampleSource sampleSource = new ExtractorSampleSource(uri, dataSource, allocator,
    BUFFER_SEGMENT_COUNT * BUFFER_SEGMENT_SIZE);

MediaCodecAudioTrackRenderer audioRenderer = new MediaCodecAudioTrackRenderer(sampleSource,
    null, true);

// Invoke the callback.
TrackRenderer[] renderers = new TrackRenderer[1];
renderers[RadioPlayer.TYPE_AUDIO] = audioRenderer;
player.prepare(renderers);
player.seekTo(0);
player.setPlayWhenReady(true);

回答1:

There's nothing wrong in your code. MP3 files are formatted in such a way that it's possible to calculate the duration of the file, and seek into any position within it.

However, AAC files do not have that luxury. You can't calulate the duration and can't seek within it.

There is a AAC file in Exoplayer Demo APK. I think if you play that, it will exhibit the same behavour.

来源：https://stackoverflow.com/questions/39777975/not-able-to-get-getduration-for-aac-file-using-exoplayer