Use actual output stream to obtain playback sample rate.

Separate setup/start of audio stream.
Resample input WAVs after stream is open.
Address review comments.

6 files changed, 46 insertions, 44 deletions

diff --git a/samples/drumthumper/src/main/cpp/DrumPlayerJNI.cpp b/samples/drumthumper/src/main/cpp/DrumPlayerJNI.cpp
index 9f55e137..d7892db8 100644
--- a/samples/drumthumper/src/main/cpp/DrumPlayerJNI.cpp
+++ b/samples/drumthumper/src/main/cpp/DrumPlayerJNI.cpp
@@ -52,6 +52,12 @@ JNIEXPORT void JNICALL Java_com_plausiblesoftware_drumthumper_DrumPlayer_setupAu
     sDTPlayer.setupAudioStream(numChannels);
 }
 
+JNIEXPORT void JNICALL
+Java_com_plausiblesoftware_drumthumper_DrumPlayer_startAudioStreamNative(
+        JNIEnv *env, jobject thiz) {
+    sDTPlayer.startStream();
+}
+
 /**
  * Native (JNI) implementation of DrumPlayer.teardownAudioStreamNative()
  */
@@ -85,8 +91,8 @@ JNIEXPORT jboolean JNICALL Java_com_plausiblesoftware_drumthumper_DrumPlayer_loa
     SampleBuffer* sampleBuffer = new SampleBuffer();
     sampleBuffer->loadSampleData(&reader);
 
-    int sampleRate = sDTPlayer.getDeviceSampleRate(2 /*channelCount*/);
-    sampleBuffer->resampleData(sampleRate);
+//    int sampleRate = sDTPlayer.getDeviceSampleRate(2 /*channelCount*/);
+//    sampleBuffer->resampleData(sampleRate);
 
     OneShotSampleSource* source = new OneShotSampleSource(sampleBuffer, pan);
     sDTPlayer.addSampleSource(source, sampleBuffer);
@@ -129,7 +135,7 @@ JNIEXPORT void JNICALL Java_com_plausiblesoftware_drumthumper_DrumPlayer_clearOu
  */
 JNIEXPORT void JNICALL Java_com_plausiblesoftware_drumthumper_DrumPlayer_restartStream(JNIEnv*, jobject) {
     sDTPlayer.resetAll();
-    if (sDTPlayer.openStream()){
+    if (sDTPlayer.openStream() && sDTPlayer.startStream()){
         __android_log_print(ANDROID_LOG_INFO, TAG, "openStream successful");
     } else {
         __android_log_print(ANDROID_LOG_ERROR, TAG, "openStream failed");
diff --git a/samples/drumthumper/src/main/java/com/plausibleaudio/drumthumper/DrumPlayer.kt b/samples/drumthumper/src/main/java/com/plausibleaudio/drumthumper/DrumPlayer.kt
index fbe75539..62c8dbfe 100644
--- a/samples/drumthumper/src/main/java/com/plausibleaudio/drumthumper/DrumPlayer.kt
+++ b/samples/drumthumper/src/main/java/com/plausibleaudio/drumthumper/DrumPlayer.kt
@@ -27,8 +27,6 @@ class DrumPlayer {
                                         // This IS NOT the channel format of the source samples
                                         // (which must be mono).
         val NUM_SAMPLE_CHANNELS: Int = 1;   // All WAV resource must be mono
-//        val SAMPLE_RATE: Int = 44100    // All the input samples are assumed to BE 44.1K
-//                                        // All the input samples are assumed to be mono.
 
         // Sample Buffer IDs
         val BASSDRUM: Int = 0
@@ -58,6 +56,10 @@ class DrumPlayer {
         setupAudioStreamNative(NUM_PLAY_CHANNELS)
     }
 
+    fun startAudioStream() {
+        startAudioStreamNative();
+    }
+
     fun teardownAudioStream() {
         teardownAudioStreamNative()
     }
@@ -99,6 +101,7 @@ class DrumPlayer {
     }
 
     external fun setupAudioStreamNative(numChannels: Int)
+    external fun startAudioStreamNative();
     external fun teardownAudioStreamNative()
 
     external fun loadWavAssetNative(
diff --git a/samples/drumthumper/src/main/java/com/plausibleaudio/drumthumper/DrumThumperActivity.kt b/samples/drumthumper/src/main/java/com/plausibleaudio/drumthumper/DrumThumperActivity.kt
index eb90cb8e..2bdd6c9f 100644
--- a/samples/drumthumper/src/main/java/com/plausibleaudio/drumthumper/DrumThumperActivity.kt
+++ b/samples/drumthumper/src/main/java/com/plausibleaudio/drumthumper/DrumThumperActivity.kt
@@ -161,7 +161,13 @@ class DrumThumperActivity : AppCompatActivity(),
 
         mAudioMgr = getSystemService(Context.AUDIO_SERVICE) as AudioManager
 
-        // mDrumPlayer.allocSampleData()
+    }
+
+    override fun onStart() {
+        super.onStart()
+
+        mDrumPlayer.setupAudioStream()
+
         var allAssetsValid = mDrumPlayer.loadWavAssets(getAssets())
 
         if (!allAssetsValid) {
@@ -171,12 +177,7 @@ class DrumThumperActivity : AppCompatActivity(),
                     Toast.LENGTH_LONG)
             toast.show()
         }
-    }
-
-    override fun onStart() {
-        super.onStart()
-
-        mDrumPlayer.setupAudioStream()
+        mDrumPlayer.startAudioStream()
 
         if (mUseDeviceChangeFallback) {
             mAudioMgr!!.registerAudioDeviceCallback(mDeviceListener, null)
@@ -232,11 +233,12 @@ class DrumThumperActivity : AppCompatActivity(),
 
         mDrumPlayer.teardownAudioStream()
 
+        mDrumPlayer.unloadWavAssets()
+
         super.onStop()
     }
 
     override fun onDestroy() {
-        mDrumPlayer.unloadWavAssets();
         super.onDestroy()
     }
 
diff --git a/samples/iolib/src/main/cpp/player/SampleBuffer.cpp b/samples/iolib/src/main/cpp/player/SampleBuffer.cpp
index a1544bd9..4a170469 100644
--- a/samples/iolib/src/main/cpp/player/SampleBuffer.cpp
+++ b/samples/iolib/src/main/cpp/player/SampleBuffer.cpp
@@ -60,22 +60,25 @@ void resampleData(const ResampleBlock& input, ResampleBlock* output) {
 
     // round up
     int32_t numOutFrames = (int32_t)(temp + 0.5);
+    // We iterate thousands of times through the loop. Roundoff error could accumulate
+    // so add a few more frames for padding
+    numOutFrames += 8;
     output->mNumFrames = numOutFrames;
 
+    const int channelCount = 1;    // 1 for mono, 2 for stereo
     MultiChannelResampler *resampler = MultiChannelResampler::make(
-            1, // channel count
+            channelCount, // channel count
             input.mSampleRate, // input sampleRate
             output->mSampleRate, // output sampleRate
             MultiChannelResampler::Quality::Medium); // conversion quality
 
     float *inputBuffer = input.mBuffer;;     // multi-channel buffer to be consumed
     float *outputBuffer = new float[numOutFrames];    // multi-channel buffer to be filled
+    memset(outputBuffer, 0, sizeof(float) * numOutFrames);
     output->mBuffer = outputBuffer;
-    int    numInputFrames = input.mNumFrames;  // number of frames of input
-    int    numOutputFrames = 0;
-    int    channelCount = 1;    // 1 for mono, 2 for stereo
 
-    int inputFramesLeft = numInputFrames;
+    int numOutputFrames = 0;
+    int inputFramesLeft = input.mNumFrames;
     while (inputFramesLeft > 0) {
         if(resampler->isWriteNeeded()) {
             resampler->writeNextFrame(inputBuffer);
diff --git a/samples/iolib/src/main/cpp/player/SimpleMultiPlayer.cpp b/samples/iolib/src/main/cpp/player/SimpleMultiPlayer.cpp
index 3c24b9e0..2cbfae77 100644
--- a/samples/iolib/src/main/cpp/player/SimpleMultiPlayer.cpp
+++ b/samples/iolib/src/main/cpp/player/SimpleMultiPlayer.cpp
@@ -72,34 +72,13 @@ void SimpleMultiPlayer::onErrorBeforeClose(AudioStream *, Result error) {
     __android_log_print(ANDROID_LOG_INFO, TAG, "==== onErrorBeforeClose() error:%d", error);
 }
 
-int SimpleMultiPlayer::getDeviceSampleRate(int32_t channelCount) {
-
-    // Create an audio stream
-    AudioStreamBuilder builder;
-    builder.setChannelCount(channelCount);
-    builder.setPerformanceMode(PerformanceMode::LowLatency);
-    builder.setSharingMode(SharingMode::Exclusive);
-    builder.setSampleRateConversionQuality(SampleRateConversionQuality::Medium);
-
-    oboe::ManagedStream audioStream;
-    Result result = builder.openManagedStream(audioStream);
-    if (result != Result::OK) {
-        __android_log_print(ANDROID_LOG_ERROR, TAG,
-                "openStream failed. Error: %s", convertToText(result));
-        return 0;
-    } else {
-        int rate = audioStream->getSampleRate();
-        return rate;
-    }
-}
-
 bool SimpleMultiPlayer::openStream() {
     __android_log_print(ANDROID_LOG_INFO, TAG, "openStream()");
 
     // Create an audio stream
     AudioStreamBuilder builder;
     builder.setChannelCount(mChannelCount);
-    // builder.setSampleRate(mSampleRate);  // we will resample to device rate
+    // we will resample source data to device rate, so take default sample rate
     builder.setCallback(this);
     builder.setPerformanceMode(PerformanceMode::LowLatency);
     builder.setSharingMode(SharingMode::Exclusive);
@@ -126,7 +105,13 @@ bool SimpleMultiPlayer::openStream() {
                 "setBufferSizeInFrames failed. Error: %s", convertToText(result));
     }
 
-    result = mAudioStream->requestStart();
+    mSampleRate = mAudioStream->getSampleRate();
+
+    return true;
+}
+
+bool SimpleMultiPlayer::startStream() {
+    Result result = mAudioStream->requestStart();
     if (result != Result::OK){
         __android_log_print(
                 ANDROID_LOG_ERROR,
@@ -154,6 +139,8 @@ void SimpleMultiPlayer::teardownAudioStream() {
 }
 
 void SimpleMultiPlayer::addSampleSource(SampleSource* source, SampleBuffer* buffer) {
+    buffer->resampleData(mSampleRate);
+
     mSampleBuffers.push_back(buffer);
     mSampleSources.push_back(source);
     mNumSampleBuffers++;
diff --git a/samples/iolib/src/main/cpp/player/SimpleMultiPlayer.h b/samples/iolib/src/main/cpp/player/SimpleMultiPlayer.h
index efec8b91..d8c9877c 100644
--- a/samples/iolib/src/main/cpp/player/SimpleMultiPlayer.h
+++ b/samples/iolib/src/main/cpp/player/SimpleMultiPlayer.h
@@ -44,9 +44,10 @@ public:
     void setupAudioStream(int32_t channelCount);
     void teardownAudioStream();
 
-    static int getDeviceSampleRate(int32_t channelCount);
-
     bool openStream();
+    bool startStream();
+
+    int getSampleRate() { return mSampleRate; }
 
     // Wave Sample Loading...
     /**
@@ -79,7 +80,7 @@ private:
     // Oboe Audio Stream
     oboe::ManagedStream mAudioStream;
 
-    // Audio attributes
+    // Playback Audio attributes
     int32_t mChannelCount;
     int32_t mSampleRate;