This code used to work. Then, maybe I changed something, somewhere (or if I know Android right, an update introduced a bug in the media player). It stopped working on some devices! Especially my Nexus S (2.3.6).
The file test.m4a (17 775 201 bytes) was downloaded by the app. To verify its integrity, I copied it to the SD and played it on my PC. No problem! Also binary-compared it with the original file, and it matched 100%.
try {
_mediaPlayer = new MediaPlayer();
_mediaPlayer.setOnCompletionListener(this);
_mediaPlayer.setOnPreparedListener(this);
_mediaPlayer.setOnSeekCompleteListener(this);
_mediaPlayer.setOnBufferingUpdateListener(this);
_mediaPlayer.setOnInfoListener(this);
_mediaPlayer.setOnErrorListener(this);
// I even tried reading the file from SD card. Same error...
File file = new File("/data/data/com.mycompany.myapp/files/MediaCache/Test.m4a");
// file.isFile() == true
// file.length() == expected value!
FileInputStream is = new FileInputStream(file);
_mediaPlayer.setDataSource(is.getFD()); // Throws!
// If I use the filename as parameter, it throws later when preparing the media player...
_mediaPlayer.prepareAsync();
}
catch (Exception e) {
// java.io.IOException: setDataSourceFD failed.: status=0x80000000
e.printStackTrace();
}
Q: What might cause this IOException for setDataSourceFD when the file is indeed valid?
UPDATE: Here’s a 98 kB audio file that I cannot play on my Nexus S (2.3.6):
http://www.2shared.com/audio/wUKoRiQk/test.html
A friend of mine runs some ZTE device (2.2) and it seems to work. I don’t get it!
I would like to tell you that MediaPlayer is running and working correctly. Below are all my hypothesis. Don’t take them too seriously.
It is your test.m4a file that is encoded in a format such that MediaPlayer can’t decode, therefore throwing out an error saying that it can’t create the MediaPlayer for you to use. Seems like you encoded it in some FFmpeg codecs you had on your computer. It would be better if you tried creating the file without using advanced codecs such as FFmpeg, as Android can’t decode advanced codecs on the fly.
However, I do not have the answer to why some smartphones can play your M4A file, while others can’t. My suggestion for you is to use a simple OGG format that Audacity already has installed, for all of your Android projects, because the OGG codec what Audacity has, is simple enough for Android to decode on the fly. I’m not claiming that many devs are using mostly OGG, just that OGG doesn’t seem to have a lot of problems with MediaPlayer and SoundPool when using simple codecs. Needs more researching…
Even my book, Beginning Android 4 Game Development, depends on OGG files.
Here’s my proof below. This is the file “test.m4a” I’m using from your link. I made it so that it runs in a endless loop, making it a 100% proof of evidence:
Now, here’s the code I made, shown below:
Notice the final String variable near the top of the code snippet. If I replace that line with this:
And re-encode your “test.m4a” file to an Ogg Vorbis file, and no other changes in the code, I can play the OGG file just fine. Here are the change logs for the OGG file:
And then it stops here. There’s no looping going around.
More evidence to support my answer:
Link 1: Android SDK Reference (Do look at the State Diagram, very important!)
And a picture (Image of your “test.m4a” and your file re-encoded into an OGG file, placed side-by-side.):