start/stop for audio player

pyaudioplayeralsa/CMakeLists.txt

@@ -3,4 +3,4 @@ cmake_minimum_required(VERSION 3.16)
 project("pyaudioplayeralsa")
 
 add_executable(play main.cpp src/WavFile.cpp)
-target_link_libraries(play -lasound)
+target_link_libraries(play -lasound -pthread)

pyaudioplayeralsa/main.cpp

@@ -28,13 +28,38 @@
 
 #include "src/WavFile.h"
 
+#include <future>
+#include <thread>
+#include <chrono>
+#include <queue>
+
 #define PCM_DEVICE "default"
 
+std::deque<std::string> queue;
+std::mutex queueMutex;
+
+static std::string getInput()
+{
+
+  std::cout << "starting input thread" << std::endl;
+  while (true)
+  {
+    std::string result;
+    std::getline(std::cin, result);
+    {
+      std::lock_guard<std::mutex> guard(queueMutex);
+      std::cout << "adding to queue" << std::endl;
+      queue.push_back(result);
+    }
+  }
+}
+
 int main(int argc, char **argv)
 {
   std::ifstream wavFileStream("test.wav", std::ios::binary);
   WavFile wav(wavFileStream);
   wavFileStream.close();
+  std::cout << "Wav samples " << wav.size() << std::endl;
 
   unsigned int pcm, tmp, dir;
   snd_pcm_t *pcm_handle;
@@ -66,6 +91,8 @@ int main(int argc, char **argv)
   if (pcm = snd_pcm_hw_params_set_channels(pcm_handle, params, wav.channels()) < 0)
     printf("ERROR: Can't set channels number. %s\n", snd_strerror(pcm));
 
+  snd_pcm_hw_params_set_buffer_size(pcm_handle, params, 2 * 2048);
+
   unsigned int rate = wav.sampleRate();
   if (pcm = snd_pcm_hw_params_set_rate_near(pcm_handle, params, &rate, 0) < 0)
     printf("ERROR: Can't set rate. %s\n", snd_strerror(pcm));
@@ -80,6 +107,7 @@ int main(int argc, char **argv)
   printf("PCM state: %s\n", snd_pcm_state_name(snd_pcm_state(pcm_handle)));
 
   snd_pcm_hw_params_get_channels(params, &tmp);
+
   printf("channels: %i ", tmp);
 
   if (tmp == 1)
@@ -95,26 +123,52 @@ int main(int argc, char **argv)
 
   buff_size = frames * wav.channels() * 2 /* 2 -> sample size */;
   buff = (char *)malloc(buff_size);
+  std::cout << "Buffer size " << buff_size << " frames " << frames << std::endl;
 
   snd_pcm_hw_params_get_period_time(params, &tmp, NULL);
 
+  std::thread inputThread(getInput);
+  bool playing = true;
+
   size_t wavFilePosition = 0;
   while (wavFilePosition < wav.size())
   {
+    {
+      std::lock_guard<std::mutex> guard(queueMutex);
+      if (queue.size() > 0)
+      {
+        queue.pop_back();
+        std::cout << "Toggling" << std::endl;
+        //snd_pcm_drain(pcm_handle);
+        std::cout << "Done" << std::endl;
+        playing = !playing;
+        if (playing)
+        {
+          std::cout << "continuing at " << wavFilePosition << std::endl;
+          snd_pcm_pause(pcm_handle, 0);
+          //snd_pcm_prepare(pcm_handle);
+        }
+        else
+          snd_pcm_pause(pcm_handle, 1);
+      }
+    }
+
+    if (!playing)
+      continue;
     size_t dataToWrite = std::min(size_t(buff_size), wav.size() - wavFilePosition);
     int framesToWrite = dataToWrite / wav.channels() / 2;
     if (pcm = snd_pcm_writei(pcm_handle, wav[wavFilePosition], framesToWrite) == -EPIPE)
     {
-      printf("XRUN.\n");
+      std::cout << "XRUN at wav position " << wavFilePosition << std::endl;
       snd_pcm_prepare(pcm_handle);
     }
     else if (pcm < 0)
-    {
       printf("ERROR. Can't write to PCM device. %s\n", snd_strerror(pcm));
-    }
+
     wavFilePosition += dataToWrite;
   }
 
+  std::cout << "done filling buffer" << std::endl;
   snd_pcm_drain(pcm_handle);
   snd_pcm_close(pcm_handle);
   free(buff);