CODEWITHSUNDEEP
audiokotlin-multiplatformcompose-desktop
Pion Developer
Pion Developer

Reputation: 189

How to play an MP3 file stored in resources folder in Kotlin Multiplatform with Jetpack Compose for Desktop?

I'm trying to play a sound in my Compose for Desktop project when pressing a button. My MP3 file is stored in the resources folder (./src/jvmMain/resources/beep.mp3).

I've been trying using the useResource function as follows (inside onClick parameter of a @Composable Button):

scope.launch {
 useResource("beep.mp3") {
                        val clip = AudioSystem.getClip()
                        val audioInputStream = AudioSystem.getAudioInputStream(
                            it
                        )
                        clip.open(audioInputStream)
                        clip.start()
                    }
}

but I get an error: Exception in thread "AWT-EventQueue-0" java.io.IOException: mark/reset not supported. I got the same error if I don't use the scope, which I define at the top level of my composable as:

val scope = rememberCoroutineScope()

Any help will be appreciated!

Upvotes: 0

Views: 1494

Answers (1)

sunny681
sunny681

Reputation: 26

A library is needed to decode MP3 files. This is the key. You may add this maven dependency:

implementation("com.googlecode.soundlibs:mp3spi:1.9.5.4")

Using Java Sound APIs you originally used:

import java.io.File
import javax.sound.sampled.AudioFormat
import javax.sound.sampled.AudioInputStream
import javax.sound.sampled.AudioSystem
import javax.sound.sampled.AudioSystem.getAudioInputStream
import javax.sound.sampled.DataLine.Info
import javax.sound.sampled.SourceDataLine

class AudioPlayer {
    fun play(path: String) {
        val file = File(path)
        getAudioInputStream(file).use { `in` ->
            val outFormat = getOutFormat(`in`.format)
            val info = Info(SourceDataLine::class.java, outFormat)
            AudioSystem.getLine(info).use { line ->
                (line as? SourceDataLine)?.let { l ->
                    l.open(outFormat)
                    l.start()
                    stream(getAudioInputStream(outFormat, `in`), l)
                    l.drain()
                    l.stop()
                }
            }
        }
    }

    private fun getOutFormat(inFormat: AudioFormat): AudioFormat {
        val ch = inFormat.channels
        val rate = inFormat.sampleRate
        return AudioFormat(AudioFormat.Encoding.PCM_SIGNED, rate, 16, ch, ch * 2, rate, false)
    }

    private fun stream(`in`: AudioInputStream, line: SourceDataLine) {
        val buffer = ByteArray(65536)
        var n = 0
        while (n != -1) {
            line.write(buffer, 0, n)
            n = `in`.read(buffer, 0, buffer.size)
        }
    }
}

And call the play method from a non-UI thread / coroutine:

AudioPlayer().play(fullPathToMP3File)

Credit to original work by oldo: https://odoepner.wordpress.com/2013/07/19/play-mp3-or-ogg-using-javax-sound-sampled-mp3spi-vorbisspi/

Upvotes: 1

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