minimodem: --alsa selects ALSA at runtime

./configure now enables --with-pulseaudio and --with-alsa by default;
either can be disabled.

minimodem --alsa: uses ALSA at runtime instead of the default PulseAudio.

README

@@ -1,10 +1,10 @@
 minimodem - software audio Bell-type or RTTY FSK modem
-Copyright (C) 2011 Kamal Mostafa <kamal@whence.com>
+Copyright (C) 2011-2012 Kamal Mostafa <kamal@whence.com>
 
 Minimodem is a command-line program which generates (or decodes) audio
 modem tones at any specified baud rate, emulating an old Bell-type or
 radio-teletype FSK modem.  The tones can be played to (or recorded from)
-the PulseAudio system or to an audio file.
+the system audio (PulseAudio or ALSA) or to an audio file.
 
 Minimodem can be used to transfer data between nearby computers using an
 audio cable (or just via sound waves), or between remote computers using

configure

@@ -3299,13 +3299,12 @@ if test "${with_alsa+set}" = set; then :
   withval=$with_alsa;
 fi
 
-if test "x$with_alsa" != "xyes"; then :
+if test "x$with_alsa" == "xno"; then :
   # then
 	use_alsa=0
 else
   # else
 	use_alsa=1
-	with_pulseaudio=no	# For now, ALSA precludes pulseaudio
 	deps_packages+=" alsa"
 fi
 

configure.ac

@@ -36,12 +36,11 @@ deps_packages+=" fftw3f"
 #   ALSA
 AC_ARG_WITH([alsa],
     AS_HELP_STRING([--without-alsa], [build without ALSA support]))
-AS_IF([test "x$with_alsa" != "xyes"],
+AS_IF([test "x$with_alsa" == "xno"],
         # then
 	use_alsa=0,
 	# else
 	use_alsa=1
-	with_pulseaudio=no	# For now, ALSA precludes pulseaudio
 	deps_packages+=" alsa")
 AC_DEFINE_UNQUOTED(USE_ALSA, $use_alsa,
 	[Define to 1 to enable ALSA support])

src/minimodem.1.in

@@ -30,7 +30,7 @@ minimodem \- software audio Bell-type or RTTY FSK modem
 is a command-line program which generates (or decodes) audio
 modem tones at any specified baud rate, emulating an old Bell-type or
 radio-teletype FSK modem.  The tones can be played to (or recorded from)
-the PulseAudio system or to an audio file.
+the system audio (PulseAudio or ALSA) or to an audio file.
 .PP
 .B minimodem
 can be used to transfer data between nearby computers using an audio
@@ -71,6 +71,10 @@ encode or decode an audio file (extension sets audio format)
 .B \-q, \-\-quiet
 Do not report CARRIER / NOCARRIER or signal analysis metrics.
 .TP
+.B \-A, \-\-alsa
+Use ALSA as the audio output system instead of the default
+PulseAudio (depending on build configuration options).
+.TP
 .B \-V, \-\-version
 print program version
 .SH {baudmode}

src/minimodem.c

@@ -255,6 +255,7 @@ usage()
     "		    -T, --txstopbits {m.n}\n"
     "		    -q, --quiet\n"
     "		    -V, --version\n"
+    "		    -A, --alsa\n"
     "		{baudmode}\n"
     "		    1200 : Bell202  1200 bps --ascii\n"
     "		     300 : Bell103   300 bps --ascii\n"
@@ -283,6 +284,20 @@ main( int argc, char*argv[] )
     float	carrier_autodetect_threshold = 0.0;
     float	bfsk_confidence_threshold = 0.6;
 
+    simpleaudio * (*simpleaudio_open_system_audio)() = NULL;
+
+    /* configure the default system audio mechanism */
+#if USE_PULSEAUDIO
+    simpleaudio_open_system_audio = simpleaudio_open_stream_pulseaudio;
+#elif USE_ALSA
+    simpleaudio_open_system_audio = simpleaudio_open_stream_alsa;
+#else
+# define _MINIMODEM_NO_SYSTEM_AUDIO
+# if !USE_SNDFILE
+#  error At least one of {USE_PULSEAUDIO,USE_ALSA,USE_SNDFILE} must be enabled!
+# endif
+#endif
+
     program_name = strrchr(argv[0], '/');
     if ( program_name )
 	program_name++;
@@ -311,9 +326,10 @@ main( int argc, char*argv[] )
 	    { "space",		1, 0, 'S' },
 	    { "txstopbits",	1, 0, 'T' },
 	    { "quiet",		0, 0, 'q' },
+	    { "alsa",		0, 0, 'A' },
 	    { 0 }
 	};
-	c = getopt_long(argc, argv, "Vtrc:a85f:b:M:S:T:q",
+	c = getopt_long(argc, argv, "Vtrc:a85f:b:M:S:T:qA",
 		long_options, &option_index);
 	if ( c == -1 )
 	    break;
@@ -365,6 +381,14 @@ main( int argc, char*argv[] )
 	    case 'q':
 			quiet_mode = 1;
 			break;
+	    case 'A':
+#if USE_ALSA
+			simpleaudio_open_system_audio = simpleaudio_open_stream_alsa;
+#else
+			fprintf(stderr, "E: This build of minimodem was configured without alsa support.\n");
+			exit(1);
+#endif
+			break;
 	    default:
 			usage();
 	}
@@ -372,26 +396,13 @@ main( int argc, char*argv[] )
     if ( TX_mode == -1 )
 	TX_mode = 0;
 
-#if !(USE_PULSEAUDIO || USE_ALSA || USE_SNDFILE)
-#error At least one of {USE_PULSEAUDIO,USE_ALSA,USE_SNDFILE} must be enabled!
-#endif
-
-#if (USE_PULSEAUDIO && USE_ALSA)
-#error For now, only one of {USE_PULSEAUDIO,USE_ALSA} can be enabled (FIXME)!
-#endif
-#if USE_PULSEAUDIO
-#define simpleaudio_open_system_audio simpleaudio_open_stream_pulseaudio
-#elif USE_ALSA
-#define simpleaudio_open_system_audio simpleaudio_open_stream_alsa
-#endif
-
     if ( filename ) {
 #if !USE_SNDFILE
 	fprintf(stderr, "E: This build of minimodem was configured without sndfile,\nE:   so the --file flag is not supported.\n");
 	exit(1);
 #endif
     } else {
-#ifndef simpleaudio_open_system_audio
+#ifdef _MINIMODEM_NO_SYSTEM_AUDIO
 	fprintf(stderr, "E: this build of minimodem was configured without system audio support,\nE:   so only the --file mode is supported.\n");
 	exit(1);
 #endif
@@ -507,11 +518,9 @@ main( int argc, char*argv[] )
 		return 1;
 	}
 
-#ifdef simpleaudio_open_system_audio
 	if ( ! sa_out )
 	    sa_out = simpleaudio_open_system_audio(SA_STREAM_PLAYBACK,
 					program_name, "output audio");
-#endif
 	if ( ! sa_out )
 	    return 1;
 
@@ -537,11 +546,10 @@ main( int argc, char*argv[] )
 	if ( ! sa )
 	    return 1;
     }
-#ifdef simpleaudio_open_system_audio
+
     if ( ! sa )
 	sa = simpleaudio_open_system_audio(SA_STREAM_RECORD,
 				program_name, "input audio");
-#endif
     if ( !sa )
         return 1;