JAVA MP2 playback (native)

Question

I have a problem with MP2 audio files and JAVA. Audio seems to be a pain in JAVA anyway. I tried using JavaLayer and Xuggler to decode and transcode the MP2 file to WAV. Both of which failed. And development of those seems to be not active. Although many are still using these. JMF or FMJ I haven't tried yet. I was wishing for more native approach.

I ended up forking JavaLayer to my project. And with a small code change I managed to seemingly get it to read all the frames from the MP2. But trying to convert it to WAV resulted in a file playable only in VLC and well, it was recognizable but distorted.

Anyway, a broad question, I apologize. I guess I'm asking that is there any JAVA + JavaLayer + MP2 gurus out there who can help me?

Original MP2: https://dl.dropboxusercontent.com/u/90134918/horng014.mp2 Failed WAV conversion: https://dl.dropboxusercontent.com/u/90134918/horng014_fail.wav

I have a public GitHub account for this project, but I haven't posted this broken code there yet.

Answer 1

Meanwhile theres's a new Java Media Framework here:

https://sourceforge.net/projects/doppio/

with a high level API for players and a low level API for using only decoders.

This player here https://sourceforge.net/projects/xamp2/ based on this media framework and can play mentioned file. Also the stuff is open source.

Answer 2

After stepping through jlayer1.01 in debugger, I conclude there are only two possibilities:

Either jlayer decodes the header word wrong, or jlayers tables and code are correct and the file's parameters deviate from what the standard defines. I lack the knowledge and time to find out wich of the two is the case.

Just because jlayer hasn't been updated for a few years does not necessarily mean its abandoned; it generally works very well with the average MP3. Why should there be an update if there aren't any known bugs left?

MP2 isn't exactly common these days; actually it hasn't even been that common 15 years ago, so it might well be the case there is a still unknown bug. Try filing a bug report and give it some time.

Answer 3

The MP2 file is is correct and MP2 is common these days, the MP2 Encoder twolame is up to date with enhanced VBR encoding. You can play the file with common players. There are two different bugs in JLayer: 1. The frame size calculation is wrong and 2. A Bit allocation table for MP2 Low Sampling Frequency (Mpeg2-Layer2) is buggy.