Adding 'cycle to next audio device'

audio_switch.c

@@ -31,7 +31,7 @@ OTHER DEALINGS IN THE SOFTWARE.
 
 
 void showUsage(const char * appName) {
- printf("Usage: %s [-a] [-c] [-t type] -s device_name\n -a : shows all devices\n -c : shows current device\n\n -t type : device type (input/output/system). Defaults to output.\n -s device_name : sets the audio device to the given device by name\n\n",appName);
+ printf("Usage: %s [-a] [-c] [-t type] [-n] -s device_name\n -a : shows all devices\n -c : shows current device\n\n -t type : device type (input/output/system). Defaults to output.\n -n : cycles the audio device to the next one\n -s device_name : sets the audio device to the given device by name\n\n",appName);
 }
 
 int runAudioSwitch(int argc, const char * argv[]) {
@@ -41,7 +41,7 @@ int runAudioSwitch(int argc, const char * argv[]) {
  int function = 0;
 
  int c;
- while ((c = getopt(argc, (char **)argv, "hact:s:")) != -1) {
+ while ((c = getopt(argc, (char **)argv, "hacnt:s:")) != -1) {
  switch (c) {
  case 'a':
  // show all
@@ -56,7 +56,12 @@ int runAudioSwitch(int argc, const char * argv[]) {
  // show help
  function = kFunctionShowHelp;
  break;
-
+
+ case 'n':
+ // cycle to the next audio device
+ function = kFunctionCycleNext;
+ break;
+
  case 's':
  // set the requestedDeviceName
  function = kFunctionSetDevice;
@@ -105,14 +110,38 @@ int runAudioSwitch(int argc, const char * argv[]) {
  return 0;
  }
 
+ if (typeRequested == kAudioTypeUnknown) typeRequested = kAudioTypeOutput;
+
+ if (function == kFunctionCycleNext) {
+ // get current device of requested type
+ chosenDeviceID = getCurrentlySelectedDeviceID(typeRequested);
+ if (chosenDeviceID == kAudioDeviceUnknown) {
+ printf("Could not find current audio device of type %s. Nothing was changed.\n", deviceTypeName(typeRequested));
+ return 1;
+ }
+
+ // find next device to current device
+ chosenDeviceID = getNextDeviceID(chosenDeviceID, typeRequested);
+ if (chosenDeviceID == kAudioDeviceUnknown) {
+ printf("Could not find next audio device of type %s. Nothing was changed.\n", deviceTypeName(typeRequested));
+ return 1;
+ }
+
+ // choose the requested audio device
+ setDevice(chosenDeviceID, typeRequested);
+ getDeviceName(chosenDeviceID, requestedDeviceName);
+ printf("%s audio device set to \"%s\"\n", deviceTypeName(typeRequested), requestedDeviceName);
+
+ return 0;
+ }
+
  if (function != kFunctionSetDevice) {
  printf("Please specify audio device.\n");
  showUsage(argv[0]);
  return 1;
  }
 
  // find the id of the requested device
- if (typeRequested == kAudioTypeUnknown) typeRequested = kAudioTypeOutput;
  chosenDeviceID = getRequestedDeviceID(requestedDeviceName, typeRequested);
  if (chosenDeviceID == kAudioDeviceUnknown) {
  printf("Could not find an audio device named \"%s\" of type %s. Nothing was changed.\n",requestedDeviceName, deviceTypeName(typeRequested));
@@ -222,6 +251,45 @@ AudioDeviceID getRequestedDeviceID(char * requestedDeviceName, ASDeviceType type
  return kAudioDeviceUnknown;
 }
 
+AudioDeviceID getNextDeviceID(AudioDeviceID currentDeviceID, ASDeviceType typeRequested) {
+ UInt32 propertySize;
+ AudioDeviceID dev_array[64];
+ int numberOfDevices = 0;
+ AudioDeviceID first_dev = kAudioDeviceUnknown;
+ int found = -1;
+
+ AudioHardwareGetPropertyInfo(kAudioHardwarePropertyDevices, &propertySize, NULL);
+ // printf("propertySize=%d\n",propertySize);
+
+ AudioHardwareGetProperty(kAudioHardwarePropertyDevices, &propertySize, dev_array);
+ numberOfDevices = (propertySize / sizeof(AudioDeviceID));
+ // printf("numberOfDevices=%d\n",numberOfDevices);
+
+ for(int i = 0; i < numberOfDevices; ++i) {
+ switch(typeRequested) {
+ case kAudioTypeInput:
+ case kAudioTypeOutput:
+ if (getDeviceType(dev_array[i]) != typeRequested) continue;
+ break;
+ case kAudioTypeSystemOutput:
+ if (getDeviceType(dev_array[i]) != kAudioTypeOutput) continue;
+ break;
+ }
+
+ if (first_dev == kAudioDeviceUnknown) {
+ first_dev = dev_array[i];
+ }
+ if (found >= 0) {
+ return dev_array[i];
+ }
+ if (dev_array[i] == currentDeviceID) {
+ found = i;
+ }
+ }
+
+ return first_dev;
+}
+
 void setDevice(AudioDeviceID newDeviceID, ASDeviceType typeRequested) {
  UInt32 propertySize = sizeof(UInt32);
 

audio_switch.h

@@ -45,7 +45,8 @@ enum {
  kFunctionSetDevice = 1,
  kFunctionShowHelp = 2,
  kFunctionShowAll = 3,
- kFunctionShowCurrent = 4
+ kFunctionShowCurrent = 4,
+ kFunctionCycleNext = 5
 };
 
 
@@ -58,6 +59,7 @@ ASDeviceType getDeviceType(AudioDeviceID deviceID);
 char *deviceTypeName(ASDeviceType device_type);
 void showCurrentlySelectedDeviceID(ASDeviceType typeRequested);
 AudioDeviceID getRequestedDeviceID(char * requestedDeviceName, ASDeviceType typeRequested);
+AudioDeviceID getNextDeviceID(AudioDeviceID currentDeviceID, ASDeviceType typeRequested);
 void setDevice(AudioDeviceID newDeviceID, ASDeviceType typeRequested);
 void showAllDevices(ASDeviceType typeRequested);