more work

src/ampswitch.cpp

@@ -18,23 +18,189 @@
 
 #include "ampswitch.h"
 
+#ifndef _GNU_SOURCE
+  #define _GNU_SOURCE //for pipe2
+#endif //_GNU_SOURCE
+#include <unistd.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <stdio.h>
+#include <signal.h>
+#include <errno.h>
+#include <math.h>
+#include <string.h>
+#include <fcntl.h>
+#include <sys/select.h>
+
+volatile bool g_stop = false;
+
 CAmpSwitch::CAmpSwitch(int argc, char *argv[])
 {
+  m_connected = false;
+  m_client = NULL;
+  m_port = NULL;
+  m_switchedon = false;
+  m_triggerlevel = 0.5f;
+  m_pipe[0] = -1;
+  m_pipe[1] = -1;
+  m_switchtime = 10.0f;
+  m_samplecounter = 0;
+  m_samplerate = 0;
 }
 
 CAmpSwitch::~CAmpSwitch()
 {
 }
 
-void CAmpSwitch::Setup()
+bool CAmpSwitch::Setup()
 {
+  signal(SIGINT, SignalHandler);
+  signal(SIGINT, SignalHandler);
+
+  if (pipe2(m_pipe, O_NONBLOCK) == -1)
+  {
+    printf("ERROR: Creating pipe: %s\n", strerror(errno));
+    return false;
+  }
+
+  return true;
 }
 
 void CAmpSwitch::Process()
 {
+  while (!g_stop)
+  {
+    if (!m_connected)
+      Connect();
+
+    fd_set pipeset;
+    FD_ZERO(&pipeset);
+    FD_SET(m_pipe[0], &pipeset);
+    struct timeval tv;
+    tv.tv_sec = 1;
+    tv.tv_usec = 0;
+    select(m_pipe[0] + 1, &pipeset, NULL, NULL, &tv);
+
+    if (FD_ISSET(m_pipe[0], &pipeset))
+      printf("Current state: %s\n", m_switchedon ? "on" : "off");
+
+    uint8_t byte;
+    while (read(m_pipe[0], &byte, 1) == 1);
+
+    sleep(1);
+  }
 }
 
 void CAmpSwitch::Cleanup()
 {
+  JackDisconnect();
+}
+
+void CAmpSwitch::Connect()
+{
+  m_connected = JackConnect();
+  if (!m_connected)
+  {
+    JackDisconnect();
+
+    printf("Waiting 10 seconds before trying again\n");
+    sleep(10);
+  }
+}
+
+bool CAmpSwitch::JackConnect()
+{
+  m_client = jack_client_open("Ampswitch", JackNoStartServer, NULL);
+
+  if (m_client == NULL)
+  {
+    printf("ERROR: Unable to connect to jack\n");
+    return false;
+  }
+
+  int returnv;
+
+  m_samplerate = jack_get_sample_rate(m_client);
+
+  returnv = jack_set_process_callback(m_client, SJackProcessCallback, this);
+  if (returnv != 0)
+  {
+    printf("ERROR: Unable to set process callback\n");
+    return false;
+  }
+
+  m_port = jack_port_register(m_client, "Input", JACK_DEFAULT_AUDIO_TYPE, JackPortIsInput, 0);
+  if (m_port == NULL)
+  {
+    printf("ERROR: Unable to register jack port\n");
+    return false;
+  }
+
+  returnv = jack_activate(m_client);
+  if (returnv != 0)
+  {
+    printf("ERROR: Unable to activate jack client\n");
+    return false;
+  }
+
+  printf("Connected to jack\n");
+
+  return true;
+}
+
+void CAmpSwitch::JackDisconnect()
+{
+  if (m_client)
+  {
+    printf("Disconnecting from jack\n");
+
+    jack_port_unregister(m_client, m_port);
+    m_port = NULL;
+
+    jack_deactivate(m_client);
+    jack_client_close(m_client);
+    m_client = NULL;
+  }
+}
+
+int CAmpSwitch::SJackProcessCallback(jack_nframes_t nframes, void *arg)
+{
+  return ((CAmpSwitch*)arg)->PJackProcessCallback(nframes);
+}
+
+int CAmpSwitch::PJackProcessCallback(jack_nframes_t nframes)
+{
+  float* jackptr = (float*)jack_port_get_buffer(m_port, nframes);
+
+  float* in = jackptr;
+  float* inend = in + nframes;
+  while (in != inend)
+  {
+    if (m_samplecounter == 0)
+    {
+      bool trigger = fabsf(*(in++)) > m_triggerlevel;
+      bool change = (m_switchedon && !trigger) || (!m_switchedon && trigger);
+      if (change)
+      {
+        m_switchedon = !m_switchedon;
+        m_samplecounter = m_switchtime * m_samplerate;
+
+        uint8_t msgbyte = 0;
+        write(m_pipe[1], &msgbyte, 1);
+      }
+    }
+    else
+    {
+      m_samplecounter--;
+    }
+  }
+
+  return 0;
+}
+
+void CAmpSwitch::SignalHandler(int signum)
+{
+  if (signum == SIGINT || signum == SIGKILL)
+    g_stop = true;
 }
 

src/ampswitch.h

@@ -19,17 +19,37 @@
 #ifndef AMPSWITCH_H
 #define AMPSWITCH_H
 
+#include <jack/jack.h>
+
 class CAmpSwitch
 {
   public:
     CAmpSwitch(int argc, char *argv[]);
     ~CAmpSwitch();
 
-    void Setup();
+    bool Setup();
     void Process();
     void Cleanup();
 
   private:
+    void        Connect();
+    bool        JackConnect();
+    void        JackDisconnect();
+
+    static int  SJackProcessCallback(jack_nframes_t nframes, void *arg);
+    int         PJackProcessCallback(jack_nframes_t nframes);
+
+    static void SignalHandler(int signum);
+
+    bool           m_connected;
+    jack_client_t* m_client;
+    jack_port_t*   m_port;
+    int            m_pipe[2];
+    bool           m_switchedon;
+    float          m_triggerlevel;
+    int            m_samplerate;
+    float          m_switchtime;
+    int            m_samplecounter;
 };
 
 #endif //AMPSWITCH_H

src/main.cpp

@@ -22,7 +22,9 @@ int main (int argc, char *argv[])
 {
   CAmpSwitch ampswitch(argc, argv);
 
-  ampswitch.Setup();
+  if (!ampswitch.Setup())
+    return 1;
+
   ampswitch.Process();
   ampswitch.Cleanup();