I have struggled with playing aac encoded audio files with Java a while now.
We had a group project at the end of our first semester and wanted to have a background music and few soundeffects in there. At the end we used WAV files, as we couldn't get the AAC's to play.
This weekend I gave it another try and searched along again, and have got a working code searched together from different sites, but nowhere was a complete working solution.
For a more comfortable usage in future projects I made me a small library for aac playback.
As it was hard to find the working solution, I wanted to share it with you, in the hope some one having the same problem in the future will have it a bit easier.
The following code is a snippet from the lib I wrote. You can have a look onto the whole lib on GitLab at
Java AAC-Player.
This lib/solution uses the aac decoder JAAD.
The player I wrote around the JAAD library is available as Maven artifact:
<dependency>
<groupId>com.gitlab.9lukas5</groupId>
<artifactId>jaad</artifactId>
<!--
check latest version on https://search.maven.org
or try the latest tag you find in git
-->
</dependency>
public static void play(File[] files)
{
// local vars
byte[] b; // array for the actual audio Data during the playback
AudioTrack track; // track we are playing atm
AudioFormat af; // the track's format
SourceDataLine line; // the line we'll use the get our audio to the speaker's
Decoder dec; // decoder to get the audio bytes
Frame frame; //
SampleBuffer buf; //
int currentTrack; // index of current track from playlist
MP4Container cont; // container to open the current track with
Movie movie; // and get the content from the container
try
{
// for-next loop to play each titel from the playlist once
for (currentTrack = 0; currentTrack < files.length; currentTrack++)
{
cont = new MP4Container(new RandomAccessFile(files[currentTrack], "r")); // open titel with random access
movie = cont.getMovie(); // get content from container,
List<Track> content = movie.getTracks();
if (content.isEmpty()) // check if container HAS content
throw new Exception ("insert error message here"); // if so,
track = (AudioTrack) movie.getTracks().get(0); // grab first track and set the audioformat
af = new AudioFormat(track.getSampleRate(), track.getSampleSize(), track.getChannelCount(), true, true);
line = AudioSystem.getSourceDataLine(af); // get a DataLine from the AudioSystem
line.open(); // open and
line.start(); // start it
dec = new Decoder(track.getDecoderSpecificInfo());
buf = new SampleBuffer();
while(track.hasMoreFrames()) // while we have frames left
{
frame = track.readNextFrame(); // read next frame,
dec.decodeFrame(frame.getData(), buf); // decode it and put into the buffer
b = buf.getData(); // write the frame data from the buffer to our byte-array
line.write(b, 0, b.length); // and from there write the byte array into our open AudioSystem DataLine
while (paused) // check if we should pause
{
Thread.sleep(500); // if yes, stay half a second
if (Thread.interrupted()) // check if we should stop possibly
{
line.close(); // if yes, close line and
return; // exit thread
}
}
if (Thread.interrupted()) // if not in pause, still check on each frame if we should
{ // stop. If so
line.close(); // close line and
return; // exit thread
}
}
line.close(); // after titel is over, close line
if (loop) // if we should loop current titel, set currentTrack -1,
currentTrack--; // as on bottom of for-next it get's +1 and so the same titel get's played again
else if (repeat && (currentTrack == files.length -1)) // else check if we are at the end of the playlist
currentTrack = -1; // and should repeat the whole list. If so, set currentTrack -1, so it get's 0 on for-next bottom
}
}
catch (LineUnavailableException | IOException | InterruptedException e)
{
e.printStackTrace();
}
}