Question

I’m trying to use the gdx-audio extensions, but am having trouble decoding mp3s. It works, but very slowly!! A 10-second file is taking 6.57 seconds to decode 🙁 Here is the method:

public void decode() {
    Mpg123Decoder decoder = new Mpg123Decoder(externalFile);

    short[] sampleArray = new short[1024];

    // read until we reach the end of the file
    while (decoder.readSamples(sampleArray, 0, sampleArray.length) > 0) {}
}

Can anyone tell me why this is taking so long?

Answer 1

Because libmpg123 is a software decoder, that does all the work on the CPU. Depending on what CPU you have, you usually only get 2x real-time decoding. We haven’t enabled ARM assembly in our libmpg123 build, that could help speeding it up a little, but usually not by much.