Detect and use ALSA for varispeed-play.

ChangeLog

@@ -1,3 +1,8 @@
+2011-11-02  Erik de Castro Lopo  <erikd AT mega-nerd DOT com>
+
+    * configure.ac examples/Makefile.am
+    Detect ALSA and use it in varispeed-play.
+
 2011-08-15  Erik de Castro Lopo  <erikd AT mega-nerd DOT com>
 
     * configure.ac

configure.ac

@@ -184,6 +184,19 @@ else
 	HAVE_SNDFILE=0
 	fi
 
+#====================================================================================
+# Check for ALSA.
+
+ALSA_LIBS=""
+
+if test x$enable_alsa != xno ; then
+	AC_CHECK_HEADERS(alsa/asoundlib.h)
+	if test x$ac_cv_header_alsa_asoundlib_h = xyes ; then
+		ALSA_LIBS="-lasound"
+		enable_alsa=yes
+		fi
+	fi
+
 #====================================================================================
 # Check for libfftw3 which is required for the test and example programs.
 
@@ -293,6 +306,8 @@ AC_SUBST(HAVE_SNDFILE)
 AC_SUBST(SNDFILE_CFLAGS)
 AC_SUBST(SNDFILE_LIBS)
 
+AC_SUBST(ALSA_LIBS)
+
 AC_CONFIG_FILES([Makefile M4/Makefile src/Version_script \
 			Win32/Makefile Win32/Makefile.mingw \
 			src/Makefile examples/Makefile tests/Makefile doc/Makefile \
@@ -322,9 +337,10 @@ if test x$ac_cv_c_compiler_gnu = xyes ; then
 AC_MSG_RESULT([
   Extra tools required for testing and examples :
 
-    Use FFTW : .................... ${ac_cv_fftw3}])
+    Have FFTW : ................... ${ac_cv_fftw3}])
 
-AC_MSG_RESULT([    Have libsndfile : ............. ${ac_cv_sndfile}
+AC_MSG_RESULT([    Have libsndfile : ............. ${ac_cv_sndfile}])
+AC_MSG_RESULT([    Have ALSA : ................... ${ac_cv_header_alsa_asoundlib_h}
 ])
 
 AC_MSG_RESULT([  Installation directories :

examples/Makefile.am

@@ -10,7 +10,7 @@ INCLUDES = -I$(srcdir)/$(SAMPLERATEDIR) @OS_SPECIFIC_INCLUDES@
 
 OS_SPECIFIC_LINKS = @OS_SPECIFIC_LINKS@
 
-SNDFILE_LIBS = @SNDFILE_LIBS@
+SNDFILE_LIBS = @SNDFILE_LIBS@ @ALSA_LIBS@
 AM_CFLAGS = @SNDFILE_CFLAGS@
 
 #===============================================================================