Preload samples for quicker startup

thetwom · Jul 28, 2022 · bab7c81 · bab7c81
1 parent 740fd0f
commit bab7c81
Show file tree

Hide file tree

Showing 3 changed files with 32 additions and 3 deletions.
diff --git a/app/src/main/java/de/moekadu/metronome/audio/AudioMixer.kt b/app/src/main/java/de/moekadu/metronome/audio/AudioMixer.kt
@@ -28,6 +28,7 @@ import android.os.Build
 import android.os.Handler
 import android.os.Looper
 import android.os.SystemClock
+import android.util.Log
 import de.moekadu.metronome.metronomeproperties.*
 import kotlinx.coroutines.*
 import kotlinx.coroutines.channels.Channel
@@ -367,6 +368,17 @@ private fun computeNoteDelayInMillis(noteStartedMessages: ArrayList<NoteStartedM
  */
 class AudioMixer (val context: Context, private val scope: CoroutineScope) {
 
+    private val noteSamplesForDifferentSampleRates = mapOf (
+        44100 to lazy {
+//            Log.v("Metronome", "AudioMixer: load samples for 44100Hz")
+            createNoteSamples(context, 44100)
+        },
+        48000 to lazy {
+//            Log.v("Metronome", "AudioMixer: load samples for 48000Hz")
+            createNoteSamples(context, 48000)
+        }
+    )
+
     ///  Note list with tracks which are played in a loop
     var noteList = ArrayList<NoteListItem>()
         set(value) {
@@ -418,6 +430,18 @@ class AudioMixer (val context: Context, private val scope: CoroutineScope) {
     private val isMuteChannel = Channel<Boolean>(Channel.CONFLATED)
     private var isMute: Boolean = false
 
+    init {
+        // preload all samples for quicker player start
+        scope.launch(Dispatchers.Main) {
+            // first load with known native sample rate, then load for all sample rates
+            val nativeSampleRate = AudioTrack.getNativeOutputSampleRate(AudioManager.STREAM_MUSIC)
+            noteSamplesForDifferentSampleRates[nativeSampleRate]?.value
+
+            for (n in noteSamplesForDifferentSampleRates)
+                n.value.value
+        }
+    }
+
     /// Create a new NoteStartedChannel.
     /**
      * @warning When this is not needed anymore, you MUST call unregisterNoteStartedChannel
@@ -479,7 +503,7 @@ class AudioMixer (val context: Context, private val scope: CoroutineScope) {
         job = scope.launch(Dispatchers.Default) {
 
             val player = createPlayer()
-            val noteSamples = createNoteSamples(context, player.sampleRate)
+            val noteSamples = noteSamplesForDifferentSampleRates[player.sampleRate]!!.value //createNoteSamples(context, player.sampleRate)
 
             val queuedNotes = ArrayList<QueuedNote>(32)
             val queuedNoteStartedChannels = ArrayList<NoteStartedMessagingAndFrame>()

diff --git a/app/src/main/java/de/moekadu/metronome/fragments/MetronomeFragment.kt b/app/src/main/java/de/moekadu/metronome/fragments/MetronomeFragment.kt
@@ -22,6 +22,7 @@ package de.moekadu.metronome.fragments
 import android.annotation.SuppressLint
 import android.content.SharedPreferences.OnSharedPreferenceChangeListener
 import android.os.Bundle
+import android.util.Log
 import android.view.*
 import android.widget.ImageButton
 import android.widget.TextView
@@ -203,7 +204,7 @@ class MetronomeFragment : Fragment() {
             }
 
             override fun onPlay() {
-                // Log.v("Metronome", "playButton:onPause()")
+                Log.v("Metronome", "MetronomeFragment: playButton:onPlay()")
                 viewModel.play()
             }
 

diff --git a/app/src/main/java/de/moekadu/metronome/services/PlayerService.kt b/app/src/main/java/de/moekadu/metronome/services/PlayerService.kt
@@ -26,6 +26,7 @@ import android.os.Binder
 import android.os.IBinder
 import android.support.v4.media.session.MediaSessionCompat
 import android.support.v4.media.session.PlaybackStateCompat
+import android.util.Log
 import androidx.lifecycle.LifecycleService
 import androidx.lifecycle.lifecycleScope
 import androidx.preference.PreferenceManager
@@ -291,20 +292,23 @@ class PlayerService : LifecycleService() {
     }
 
     fun startPlay() {
-        // Log.v("Metronome", "PlayerService:startPlay")
+//        Log.v("Metronome", "PlayerService:startPlay : setting playbackState")
         playbackState = playbackStateBuilder.setState(
             PlaybackStateCompat.STATE_PLAYING,
             PlaybackStateCompat.PLAYBACK_POSITION_UNKNOWN,
             bpm.bpm
         ).build()
         mediaSession?.setPlaybackState(playbackState)
 
+//        Log.v("Metronome", "PlayerService:startPlay : setting notification")
         notification?.state = state
         notification?.let {
             startForeground(PlayerNotification.id, it.notification)
         }
 
+//        Log.v("Metronome", "PlayerService:startPlay : starting mixer")
         audioMixer?.start()
+//        Log.v("Metronome", "PlayerService:startPlay : run statusChangedListeners")
         statusChangedListeners.forEach { s -> s.onPlay() }
     }