录音

RecordActivity.kt

import android.media.AudioFormat
import android.media.AudioRecord
import android.media.MediaRecorder
import androidx.appcompat.app.AppCompatActivity
import android.os.Bundle
import android.os.Handler
import android.util.Log
import android.view.View
import android.widget.Button
import java.io.*
import java.lang.Exception

class MainActivity : AppCompatActivity(), View.OnClickListener {

    private var mRecordBufferSize = 0
    private var mRecordInstance: AudioRecord? = null
    private var saveVoiceByte: ByteArrayOutputStream? = null
    private var isRecord = false

    override fun onClick(v: View?) {
        when (v?.id) {
            R.id.start -> {
                isRecord = true
                Thread {
                    startRecord()
                }.start()

                Handler().postDelayed({
                    stopRecord()
                }, 60000)
            }
            R.id.stop -> {
                stopRecord()
            }
        }
    }

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)

        findViewById<Button>(R.id.start).setOnClickListener(this)
        findViewById<Button>(R.id.stop).setOnClickListener(this)

        val file = File(AUDIO_FILE)
        val data = file.readBytes()
        Log.d(TAG, "data size: ${data.size}")
    }

    private fun stopRecord() {
        Log.d(TAG, "stop record")
        if (mRecordInstance != null) {
            mRecordInstance?.stop()
            mRecordInstance?.release()
            mRecordInstance = null
            isRecord = false
        }
    }

    private fun startRecord() {
        Log.d(TAG, "start record")
        try {
            val channelConfiguration = AudioFormat.CHANNEL_IN_MONO
            val audioEncodingBits = AudioFormat.ENCODING_PCM_16BIT
            mRecordBufferSize =
                AudioRecord.getMinBufferSize(SAMPLE_RATE, channelConfiguration, audioEncodingBits)
            mRecordInstance = AudioRecord(
                MediaRecorder.AudioSource.MIC, SAMPLE_RATE, channelConfiguration,
                audioEncodingBits, mRecordBufferSize
            )
            mRecordInstance?.channelCount
            val file = File(AUDIO_FILE)
            if (file.exists()) {
                file.delete()
            }
            val fos = FileOutputStream(file)
            if (mRecordInstance != null && mRecordInstance?.state == AudioRecord.STATE_INITIALIZED) {
                mRecordInstance?.startRecording()
            }
            val audiodata = ByteArray(mRecordBufferSize)
            var readsize: Int
            saveVoiceByte = ByteArrayOutputStream()
            while (isRecord) {
                readsize = mRecordInstance!!.read(audiodata, 0, mRecordBufferSize)
                if (AudioRecord.ERROR_INVALID_OPERATION != readsize) {
                    saveVoiceByte?.write(audiodata, 0, readsize)
                    fos.write(audiodata, 0, readsize)
                }
            }
            saveVoiceByte?.close()
            fos.close()
        } catch (e: Exception) {
            Log.e(TAG, "error start record.", e)
        }
    }

    companion object {
        private const val TAG = "MainActivity"
        private const val AUDIO_FILE = "/sdcard/test.pcm"
        private const val SAMPLE_RATE = 16000
    }
}