improvements & fixes for pa_devices

c_src/membrane_portaudio_plugin/pa_devices.c

@@ -1,40 +1,38 @@
 #include "pa_devices.h"
 
 UNIFEX_TERM list(UnifexEnv *env) {
+  UNIFEX_TERM result;
   Pa_Initialize();
-  int numDevices = Pa_GetDeviceCount();
-  device devices[numDevices];
-  if (numDevices < 0) {
-    printf("\nERROR: Pa_CountDevices returned 0x%x\n", numDevices);
-    return list_result(env, devices, numDevices);
-  } else if (numDevices == 0) {
-    return list_result(env, devices, numDevices);
-  } else {
-    int default_input_id = Pa_GetDefaultInputDevice();
-    int default_output_id = Pa_GetDefaultOutputDevice();
-    for (int i = 0; i < numDevices; i++) {
-      const PaDeviceInfo *device_info = Pa_GetDeviceInfo(i);
-
-      if (i == default_input_id) {
-        devices[i].default_device = DEFAULT_DEVICE_INPUT;
-      } else if (i == default_output_id) {
-        devices[i].default_device = DEFAULT_DEVICE_OUTPUT;
-      } else {
-        devices[i].default_device = DEFAULT_DEVICE_FALSE;
-      }
-
-      devices[i].name = malloc(strlen(device_info->name) + 1);
-      if (device_info->name != NULL) {
-        strcpy(devices[i].name, device_info->name);
-      }
+  int num_devices = Pa_GetDeviceCount();
+  if (num_devices < 0) {
+    char error[2048];
+    sprintf(error, "Pa_CountDevices returned error, code: %d", num_devices);
+    result = unifex_raise(env, error);
+    goto list_error;
+  }
+  device *devices = unifex_alloc(sizeof(device) * num_devices);
+  int default_input_id = Pa_GetDefaultInputDevice();
+  int default_output_id = Pa_GetDefaultOutputDevice();
+  for (int i = 0; i < num_devices; i++) {
+    const PaDeviceInfo *device_info = Pa_GetDeviceInfo(i);
 
-      devices[i].id = i;
-      devices[i].max_output_channels = device_info->maxOutputChannels;
-      devices[i].max_input_channels = device_info->maxInputChannels;
-      devices[i].default_sample_rate = device_info->defaultSampleRate;
+    if (i == default_input_id) {
+      devices[i].default_device = DEFAULT_DEVICE_INPUT;
+    } else if (i == default_output_id) {
+      devices[i].default_device = DEFAULT_DEVICE_OUTPUT;
+    } else {
+      devices[i].default_device = DEFAULT_DEVICE_FALSE;
     }
+
+    devices[i].name = (char *)device_info->name;
+    devices[i].id = i;
+    devices[i].max_output_channels = device_info->maxOutputChannels;
+    devices[i].max_input_channels = device_info->maxInputChannels;
+    devices[i].default_sample_rate = device_info->defaultSampleRate;
   }
 
+  result = list_result(env, devices, num_devices);
+list_error:
   Pa_Terminate();
-  return list_result(env, devices, numDevices);
+  return result;
 }

lib/membrane_portaudio.ex

@@ -19,9 +19,21 @@ defmodule Membrane.PortAudio do
   """
   @spec print_devices() :: :ok
   def print_devices() do
-    Application.ensure_all_started(:membrane_portaudio_plugin)
+    IO.inspect(list_devices(),
+      pretty: true,
+      limit: :infinity,
+      syntax_colors: IO.ANSI.syntax_colors()
+    )
+
+    :ok
+  end
 
+  @doc """
+  Returns a list of available audio devices.
+  """
+  @spec list_devices() :: [Membrane.PortAudio.Device.t()]
+  def list_devices() do
+    Application.ensure_all_started(:membrane_portaudio_plugin)
     __MODULE__.SyncExecutor.apply(__MODULE__.Devices, :list, [])
-    |> IO.inspect()
   end
 end

lib/membrane_portaudio_plugin/device.ex

@@ -1,10 +1,27 @@
 defmodule Membrane.PortAudio.Device do
-  defstruct [
+  @moduledoc """
+  Struct carrying information about an audio device.
+
+  See `Membrane.PortAudio.list_devices/0` and `Membrane.PortAudio.print_devices/0`.
+  """
+
+  @type t :: %__MODULE__{
+          id: non_neg_integer(),
+          name: String.t(),
+          max_input_channels: non_neg_integer(),
+          max_output_channels: non_neg_integer(),
+          default_device: false | :input | :output,
+          default_sample_rate: float()
+        }
+
+  @enforce_keys [
     :id,
     :name,
     :max_input_channels,
     :max_output_channels,
-    :is_default,
+    :default_device,
     :default_sample_rate
   ]
+
+  defstruct @enforce_keys
 end

test/membrane_portaudio_plugin/devices_test.exs

@@ -0,0 +1,8 @@
+defmodule Membrane.Portaudio.DevicesTest do
+  use ExUnit.Case, async: true
+
+  test "list devices" do
+    devices = Membrane.PortAudio.list_devices()
+    Enum.each(devices, &assert(%Membrane.PortAudio.Device{} = &1))
+  end
+end