add setting for default audio backend and improve selection logic

config.h.in

@@ -2,6 +2,7 @@
 
 #define DEFAULT_CODEC "@default_codec@"
 #define DEFAULT_PIX_FMT "@default_pix_fmt@"
+#define DEFAULT_AUDIO_BACKEND "@default_audio_backend@"
 #define DEFAULT_AUDIO_CODEC "@default_audio_codec@"
 #define DEFAULT_AUDIO_SAMPLE_RATE @default_audio_sample_rate@
 #define DEFAULT_CONTAINER_FORMAT "@default_container_format@"

manpage/wf-recorder.1

@@ -25,6 +25,7 @@
 .Op Fl p, -codec-param Op Ar option_param=option_value
 .Op Fl v, -version
 .Op Fl x, -pixel-format
+.Op Fl -audio-backend Ar audio_backend
 .Op Fl C, -audio-codec Ar output_audio_codec
 .Op Fl P, -audio-codec-param Op Ar option_param=option_value
 .Op Fl R, -sample-rate Ar sample_rate
@@ -147,6 +148,9 @@ Set the output pixel format.
 List available formats using
 .Dl $ ffmpeg -pix_fmts
 .Pp
+.It Fl  -audio-backend Ar audio_backend
+Specifies the audio backend to be used when -a is set.
+.Pp
 .It Fl C , -audio-codec Ar output_audio_codec
 Specifies the codec of the audio.
 .Pp

meson.build

@@ -47,22 +47,67 @@ project_sources = ['src/frame-writer.cpp', 'src/main.cpp', 'src/averr.c']
 wayland_client = dependency('wayland-client', version: '>=1.20')
 wayland_protos = dependency('wayland-protocols', version: '>=1.14')
 
-pulse = dependency('libpulse-simple', required : get_option('pulse'))
-pipewire = dependency('libpipewire-0.3', required : get_option('pipewire'))
-
-if pipewire.found()
-    conf_data.set('HAVE_PIPEWIRE', true)
-    project_sources += 'src/pipewire.cpp'
-endif
-if pulse.found()
-    conf_data.set('HAVE_PULSE', true)
-    project_sources += 'src/pulse.cpp'
-endif
-if pipewire.found() or pulse.found()
+audio_backends = {
+    'pulse': {
+      'dependency': dependency('libpulse-simple', required: false),
+      'sources': ['src/pulse.cpp'],
+      'define': 'HAVE_PULSE'
+    },
+    'pipewire': {
+      'dependency': dependency('libpipewire-0.3', required: false),
+      'sources': ['src/pipewire.cpp'],
+      'define': 'HAVE_PIPEWIRE'
+    }
+}
+
+default_audio_backend = get_option('default_audio_backend')
+message('Using default audio backend: @0@'.format(default_audio_backend))
+have_audio = false
+audio_deps = []
+
+foreach backend_name, backend_data : audio_backends
+  if default_audio_backend == backend_name and not backend_data['dependency'].found()
+    error('Default audio backend set to @0@, but @1@ dependency was not found!'.format(backend_name, backend_data['dependency'].name()))
+  endif
+
+  if default_audio_backend == backend_name and get_option(backend_name).disabled()
+    error('Default audio backend set to @0@, but @1@ support is disabled!'.format(backend_name, backend_name))
+  endif
+
+  if get_option(backend_name).enabled() and not backend_data['dependency'].found()
+    error('@0@ support is enabled, but @1@ dependency was not found!'.format(backend_name, backend_data['dependency'].name()))
+  endif
+
+  if backend_data['dependency'].found() and not get_option(backend_name).disabled()
+    conf_data.set(backend_data['define'], true)
+    project_sources += backend_data['sources']
+    audio_deps += backend_data['dependency']
+    have_audio = true
+  else
+    conf_data.set(backend_data['define'], false)
+  endif
+endforeach
+
+if have_audio
     conf_data.set('HAVE_AUDIO', true)
     project_sources += 'src/audio.cpp'
+
+    if default_audio_backend == 'auto'
+      if conf_data.get('HAVE_PULSE')
+        default_audio_backend = 'pulse'
+      else
+        foreach backend_name, backend_data : audio_backends
+          if conf_data.get(backend_data['define'])
+            default_audio_backend = backend_name
+            break
+          endif
+        endforeach
+      endif
+    endif
 endif
 
+conf_data.set('default_audio_backend', default_audio_backend)
+
 libavutil = dependency('libavutil')
 libavcodec = dependency('libavcodec')
 libavformat = dependency('libavformat')
@@ -87,9 +132,22 @@ subdir('proto')
 dependencies = [
     wayland_client, wayland_protos,
     libavutil, libavcodec, libavformat, libavdevice, libavfilter,
-    wf_protos, threads, pipewire, pulse, swr, gbm, drm
-]
+    wf_protos, threads, swr, gbm, drm
+] + audio_deps
 
 executable('wf-recorder', project_sources,
         dependencies: dependencies,
         install: true)
+
+summary = [
+	'',
+	'----------------',
+	'wf-recorder @0@'.format(meson.project_version()),
+    '----------------',
+    'Default audio backend: @0@'.format(default_audio_backend),
+]
+
+foreach backend_name, backend_data : audio_backends
+  summary += ['  - @0@: @1@'.format(backend_name, conf_data.get(backend_data['define']))]
+endforeach
+message('\n'.join(summary))

meson_options.txt

@@ -6,3 +6,4 @@ option('default_container_format', type: 'string', value: 'mkv', description: 'C
 option('fallback_audio_sample_fmt', type: 'string', value: 's16', description: 'Fallback audio sample format that will be used if wf-recorder cannot determine the sample formats supported by a codec')
 option('pulse', type: 'feature', value: 'auto', description: 'Enable Pulseaudio')
 option('pipewire', type: 'feature', value: 'auto', description: 'Enable PipeWire')
+option('default_audio_backend', type: 'combo', choices: ['auto', 'pulse', 'pipewire'], value: 'auto', description: 'Default audio backend')

src/audio.cpp

@@ -12,7 +12,7 @@
 AudioReader *AudioReader::create(AudioReaderParams params)
 {
 #ifdef HAVE_PIPEWIRE
-    if (getenv("WF_RECORDER_PIPEWIRE")) {
+    if (params.audio_backend == "pipewire") {
         AudioReader *pw = new PipeWireReader;
         pw->params = params;
         if (pw->init())
@@ -21,11 +21,13 @@ AudioReader *AudioReader::create(AudioReaderParams params)
     }
 #endif
 #ifdef HAVE_PULSE
-    AudioReader *pa = new PulseReader;
-    pa->params = params;
-    if (pa->init())
-        return pa;
-    delete pa;
+    if (params.audio_backend == "pulse") {
+        AudioReader *pa = new PulseReader;
+        pa->params = params;
+        if (pa->init())
+            return pa;
+        delete pa;
+    }
 #endif
     return nullptr;
 }

src/audio.hpp

@@ -3,13 +3,17 @@
 
 #include <stdlib.h>
 #include <stdint.h>
+#include "config.h"
+#include <string>
 
 struct AudioReaderParams
 {
     size_t audio_frame_size;
     uint32_t sample_rate;
     /* Can be NULL */
     char *audio_source;
+
+    std::string audio_backend = DEFAULT_AUDIO_BACKEND;
 };
 
 class AudioReader

src/main.cpp

@@ -892,6 +892,9 @@ Use Ctrl+C to stop.)");
     
   -B. --buffrate            This option is used to specify the buffers expected framerate. this 
                             may help when encoders are expecting specific or limited framerate.
+
+  --audio-backend           Specifies the audio backend among the available backends, for ex.
+                            --audio-backend=pipewire
   
   -C, --audio-codec         Specifies the codec of the audio. These can be found by running:
                             ffmpeg -encoders
@@ -1010,6 +1013,7 @@ int main(int argc, char *argv[])
         { "codec-param",       required_argument, NULL, 'p' },
         { "framerate",         required_argument, NULL, 'r' },
         { "pixel-format",      required_argument, NULL, 'x' },
+        { "audio-backend",     required_argument, NULL, '*' },
         { "audio-codec",       required_argument, NULL, 'C' },
         { "audio-codec-param", required_argument, NULL, 'P' },
         { "sample-rate",       required_argument, NULL, 'R' },
@@ -1131,6 +1135,10 @@ int main(int argc, char *argv[])
                 force_overwrite = true;
                 break;
 
+            case '*':
+                audioParams.audio_backend = optarg;
+                break;
+
             default:
                 printf("Unsupported command line argument %s\n", optarg);
         }