espeak-ng: support specifying the device name from the command line

CHANGELOG.md

 *  Support the `--compile-phonemes` command-line option.
 *  Support the `--compile-intonations` command-line option.
 *  Support SSML <phoneme alphabet="espeak" ph="..."> tags.
+*  Added man files for the `speak-ng` and `espeak-ng` command-line programs.
+*  Created a companion espeak-ng API to provide more detailed error codes and
+   provide access to the new espeak-ng functionality.
+
+build:
+
+*  Build the code with a C99 compiler, instead of a C++ compiler.
 *  Use -fPIC to support sparc/sparc64 architectures.
 *  Use the system's portaudio header files.
 *  Use the system's sonic library and header files.
-*  Added man files for the `speak-ng` and `espeak-ng` command-line programs.
 *  Output phoneme compilation errors to stderr.
 *  Generate build failures if building phoneme, intonation or dictionary files
    contain errors.
 
 restructuring:
 
-*  Build the code with a C99 compiler, instead of a C++ compiler.
 *  Moved the library code to `src/libespeak-ng`.
 *  Renamed `espeak` to `espeak-ng`.
 *  Renamed `speak` to `speak-ng`.

src/espeak-ng.1.ronn

 If neither -f nor --stdin are provided, <words> are spoken, or if no
 words are provided then text is spoken from stdin a line at a time.
 
+  * `-d <device>`:
+    Use the specified device to speak the audio on. If not specified, the
+    default audio device is used.
+
   * `-q`:
     Quiet, don't produce any speech (may be useful with -x).
 

src/espeak-ng.c

     "is spoken from stdin, each line separately.\n\n"
     "-a <integer>\n"
     "\t   Amplitude, 0 to 200, default is 100\n"
+    "-d <device>\n"
+    "\t   Use the specified device to speak the audio on. If not specified, the\n"
+    "\t   default audio device is used.\n"
     "-g <integer>\n"
     "\t   Word gap. Pause between words, units of 10mS at the default speed\n"
     "-k <integer>\n"
 };
 int optind;
 static int optional_argument;
-static const char *arg_opts = "abfgklpsvw"; // which options have arguments
+static const char *arg_opts = "abdfgklpsvw"; // which options have arguments
 static char *opt_string = "";
 #define no_argument 0
 #define required_argument 1
 	espeak_VOICE voice_select;
 	char filename[200];
 	char voicename[40];
+	char devicename[200];
 	#define N_PUNCTLIST 100
 	wchar_t option_punctlist[N_PUNCTLIST];
 
 	voicename[0] = 0;
 	wavefile[0] = 0;
 	filename[0] = 0;
+	devicename[0] = 0;
 	option_punctlist[0] = 0;
 
 #ifdef NEED_GETOPT
 		}
 #else
 	while (true) {
-		c = getopt_long(argc, argv, "a:b:f:g:hk:l:mp:qs:v:w:xXz",
+		c = getopt_long(argc, argv, "a:b:d:f:g:hk:l:mp:qs:v:w:xXz",
 		                long_options, &option_index);
 
 		// Detect the end of the options.
 			else
 				synth_flags |= espeakCHARS_8BIT;
 			break;
+		case 'd':
+			strncpy0(devicename, optarg2, sizeof(devicename));
+			break;
 		case 'h':
 			printf("\n");
 			PrintVersion();
 
 	if (option_waveout || quiet) {
 		// writing to a file (or no output), we can use synchronous mode
-		espeak_ng_InitializeOutput(ENOUTPUT_MODE_SYNCHRONOUS, 0, NULL);
+		result = espeak_ng_InitializeOutput(ENOUTPUT_MODE_SYNCHRONOUS, 0, devicename[0] ? devicename : NULL);
 		samplerate = espeak_ng_GetSampleRate();
 		samples_split = samplerate * samples_split_seconds;
 
 		}
 	} else {
 		// play the sound output
-		espeak_ng_InitializeOutput(ENOUTPUT_MODE_SPEAK_AUDIO, 0, NULL);
+		result = espeak_ng_InitializeOutput(ENOUTPUT_MODE_SPEAK_AUDIO, 0, devicename[0] ? devicename : NULL);
 		samplerate = espeak_ng_GetSampleRate();
 	}
 
+	if (result != ENS_OK) {
+		fprintf(stderr, "Initialization failed.\n");
+		exit(1);
+	}
+
 	if (voicename[0] == 0)
 		strcpy(voicename, "default");