From f10d489df94ed075c94511fde2b020af9b247c1a Mon Sep 17 00:00:00 2001
From: Daniel Jones <daniel@jones.org.uk>
Date: Tue, 22 Oct 2024 13:42:42 +0100
Subject: [PATCH] miniaudio: Support for selecting input device

---
 .../signalflow/node/io/output/miniaudio.h     |  4 +-
 source/src/node/io/input/miniaudio.cpp        | 43 ++++++++++++++++++-
 source/src/node/io/output/miniaudio.cpp       | 14 +++---
 3 files changed, 52 insertions(+), 9 deletions(-)

diff --git a/source/include/signalflow/node/io/output/miniaudio.h b/source/include/signalflow/node/io/output/miniaudio.h
index 36bfa4ca..c2e03096 100644
--- a/source/include/signalflow/node/io/output/miniaudio.h
+++ b/source/include/signalflow/node/io/output/miniaudio.h
@@ -29,13 +29,15 @@ class AudioOut : public AudioOut_Abstract
     static std::list<std::string> get_input_device_names(std::string backend_name = "");
     static std::list<std::string> get_backend_names();
 
-private:
     /*--------------------------------------------------------------------------------
      * Initialise a new miniaudio context, using the specified backend name if
      * present, or the default backend otherwise.
+     *
+     * Public because AudioIn also uses this method.
      *-------------------------------------------------------------------------------*/
     static void init_context(ma_context *context, std::string backend_name = "");
 
+private:
     std::string backend_name;
     std::string device_name;
     ma_context context;
diff --git a/source/src/node/io/input/miniaudio.cpp b/source/src/node/io/input/miniaudio.cpp
index 29dc5fab..75b62e39 100644
--- a/source/src/node/io/input/miniaudio.cpp
+++ b/source/src/node/io/input/miniaudio.cpp
@@ -57,6 +57,7 @@ AudioIn::~AudioIn()
 
 void AudioIn::init()
 {
+    ma_result rv;
     ma_device_config config = ma_device_config_init(ma_device_type_capture);
     config.capture.format = ma_format_f32;
     config.capture.channels = this->num_channels;
@@ -64,7 +65,47 @@ void AudioIn::init()
     config.sampleRate = this->get_graph()->get_sample_rate();
     config.dataCallback = read_callback;
 
-    ma_result rv = ma_device_init(NULL, &config, &device);
+    ma_device_info *capture_devices;
+    ma_uint32 capture_device_count;
+
+    // TODO: Add get_input_backend_name
+    AudioOut::init_context(&this->context, this->get_graph()->get_config().get_output_backend_name());
+
+    rv = ma_context_get_devices(&this->context,
+                                NULL,
+                                NULL,
+                                &capture_devices,
+                                &capture_device_count);
+    int selected_device_index = -1;
+    std::string device_name = this->get_graph()->get_config().get_input_device_name();
+
+    if (!device_name.empty())
+    {
+        for (unsigned int i = 0; i < capture_device_count; i++)
+        {
+            /*-----------------------------------------------------------------------*
+             * For ease of use, SignalFlow allows for partial matches so that only
+             * the first part of the device names needs to be specified. However,
+             * an errors is thrown if the match is ambiguous.
+             *-----------------------------------------------------------------------*/
+            if (strncmp(capture_devices[i].name, device_name.c_str(), strlen(device_name.c_str())) == 0)
+            {
+                if (selected_device_index != -1)
+                {
+                    throw audio_io_exception("More than one audio device found matching name '" + device_name + "'");
+                }
+                selected_device_index = i;
+            }
+        }
+        if (selected_device_index == -1)
+        {
+            throw audio_io_exception("No audio device found matching name '" + device_name + "'");
+        }
+
+        config.capture.pDeviceID = &capture_devices[selected_device_index].id;
+    }
+
+    rv = ma_device_init(NULL, &config, &device);
     if (rv != MA_SUCCESS)
     {
         throw audio_io_exception("miniaudio: Error initialising input device");
diff --git a/source/src/node/io/output/miniaudio.cpp b/source/src/node/io/output/miniaudio.cpp
index d69b291b..9b0c257b 100644
--- a/source/src/node/io/output/miniaudio.cpp
+++ b/source/src/node/io/output/miniaudio.cpp
@@ -98,8 +98,6 @@ void AudioOut::init()
 
     ma_device_info *playback_devices;
     ma_uint32 playback_device_count;
-    ma_device_info *capture_devices;
-    ma_uint32 capture_device_count;
     ma_result rv;
 
     AudioOut::init_context(&this->context, this->backend_name);
@@ -107,13 +105,18 @@ void AudioOut::init()
     rv = ma_context_get_devices(&this->context,
                                 &playback_devices,
                                 &playback_device_count,
-                                &capture_devices,
-                                &capture_device_count);
+                                NULL,
+                                NULL);
     int selected_device_index = -1;
     if (!this->device_name.empty())
     {
         for (unsigned int i = 0; i < playback_device_count; i++)
         {
+            /*-----------------------------------------------------------------------*
+             * For ease of use, SignalFlow allows for partial matches so that only
+             * the first part of the device names needs to be specified. However,
+             * an errors is thrown if the match is ambiguous.
+             *-----------------------------------------------------------------------*/
             if (strncmp(playback_devices[i].name, device_name.c_str(), strlen(device_name.c_str())) == 0)
             {
                 if (selected_device_index != -1)
@@ -145,9 +148,6 @@ void AudioOut::init()
     config.sampleRate = this->sample_rate;
     config.dataCallback = data_callback;
 
-    // Buffer blocks into a fixed number of frames
-    config.noFixedSizedCallback = 1;
-
     // On Core Audio, let the application select a preferred sample rate.
     config.coreaudio.allowNominalSampleRateChange = 1;