Optionally use PortAudio as an audio back-end

.travis.yml

@@ -0,0 +1,23 @@
+sudo: false
+dist: xenial
+
+language: c
+
+addons:
+  apt:
+    packages:
+      - libasound2-dev
+      - libmp3lame-dev
+      - libsndfile1-dev
+      - libvorbis-dev
+      - portaudio19-dev
+
+before_script:
+  - mkdir build && cd build
+
+script:
+  - cmake .. && make
+  - cmake .. -DCMAKE_BUILD_TYPE=Debug && make
+  - cmake .. -DCMAKE_BUILD_TYPE=Release && make
+  - cmake .. -DENABLE_SNDFILE=ON -DENABLE_MP3LAME=ON -DENABLE_VORBIS=ON && make
+  - cmake .. -DENABLE_PORTAUDIO=ON && make

CMakeLists.txt

@@ -16,6 +16,12 @@ if(CMAKE_BUILD_TYPE MATCHES Debug)
 	set(DEBUG TRUE)
 endif()
 
+if(CMAKE_SYSTEM_NAME MATCHES Linux)
+	option(ENABLE_PORTAUDIO "Use PortAudio as an audio back-end.")
+else()
+	set(ENABLE_PORTAUDIO ON)
+endif()
+
 option(ENABLE_MP3LAME "Enable MP3 support.")
 option(ENABLE_SNDFILE "Enable WAV support.")
 option(ENABLE_VORBIS "Enable OGG support.")
@@ -40,8 +46,13 @@ target_link_libraries(svar m)
 find_package(Threads REQUIRED)
 target_link_libraries(svar Threads::Threads)
 
-pkg_check_modules(ALSA REQUIRED IMPORTED_TARGET alsa)
-target_link_libraries(svar PkgConfig::ALSA)
+if(ENABLE_PORTAUDIO)
+	pkg_check_modules(PortAudio REQUIRED IMPORTED_TARGET portaudio-2.0)
+	target_link_libraries(svar PkgConfig::PortAudio)
+else()
+	pkg_check_modules(ALSA REQUIRED IMPORTED_TARGET alsa)
+	target_link_libraries(svar PkgConfig::ALSA)
+endif()
 
 if(ENABLE_SNDFILE)
 	pkg_check_modules(SNDFile REQUIRED IMPORTED_TARGET sndfile)

README.md

@@ -4,8 +4,12 @@ SVAR - Simple Voice Activated Recorder
 It is a simple console application (low memory footprint and CPU usage) designed for recording
 audio when a specified signal level is exceeded. It is commonly known solution called Voice
 Operated Recording (VOR). When the signal level is low for longer than the fadeout time, audio
-recording is paused. Capturing the audio signal is based on the
-[ALSA](http://www.alsa-project.org/) technology, so it should work on all modern Linux systems.
+recording is paused.
+
+On Linux systems, capturing the audio signal is based on the [ALSA](http://www.alsa-project.org/)
+technology. For all other systems, [PortAudio](http://www.portaudio.com/) library will be used.
+Alternatively, it is possible to force PortAudio back-end on Linux systems by adding
+`-DENABLE_PORTAUDIO=ON` to the CMake configuration step.
 
 Currently this application supports four output formats:
 - RAW (PCM 16bit interleaved)

cmake/FindMp3Lame.cmake

@@ -3,6 +3,8 @@
 find_path(LAME_INCLUDE_DIR lame/lame.h)
 find_library(LAME_LIBRARIES NAMES mp3lame)
 
+mark_as_advanced(LAME_INCLUDE_DIR)
+
 if(LAME_INCLUDE_DIR AND LAME_LIBRARIES)
 
 	add_library(Mp3Lame::Mp3Lame INTERFACE IMPORTED)

config.h.in

@@ -6,11 +6,20 @@
 /* Define to 1 if debugging is enabled. */
 #cmakedefine DEBUG 1
 
-/* Define to 1 if MP3LAME is enabled. */
+/* Define to 1 if PortAudio is enabled. */
+#cmakedefine ENABLE_PORTAUDIO 1
+
+/* Define to 1 if Mp3Lame is enabled. */
 #cmakedefine ENABLE_MP3LAME 1
 
-/* Define to 1 if SNDFILE is enabled. */
+/* Define to 1 if SNDFile is enabled. */
 #cmakedefine ENABLE_SNDFILE 1
 
-/* Define to 1 if OGG is enabled. */
+/* Define to 1 if Ogg Vorbis is enabled. */
 #cmakedefine ENABLE_VORBIS 1
+
+/* Define to the name of this project. */
+#define PROJECT_NAME "@PROJECT_NAME@"
+
+/* Define to the version of this project. */
+#define PROJECT_VERSION "@PROJECT_VERSION@"