[vlc-devel] [PATCH 1/2] core: add an option to print the list of audio devices

[Thomas Guillem]

Add config_PrintAdvancedHelp() to deal with such help messages (see function
comment). This function could be used to print other useful lists in the
future.
---
 src/config/configuration.h |  1 +
 src/config/help.c          | 60 ++++++++++++++++++++++++++++++++++++++++++++++
 src/libvlc-module.c        |  4 ++++
 src/libvlc.c               |  6 +++++
 4 files changed, 71 insertions(+)

diff --git a/src/config/configuration.h b/src/config/configuration.h
index dd02c7f4af..d292588def 100644
--- a/src/config/configuration.h
+++ b/src/config/configuration.h
@@ -37,6 +37,7 @@ int config_LoadConfigFile( vlc_object_t * );
 #define config_LoadCmdLine(a,b,c,d) config_LoadCmdLine(VLC_OBJECT(a),b,c,d)
 #define config_LoadConfigFile(a) config_LoadConfigFile(VLC_OBJECT(a))
 bool config_PrintHelp (vlc_object_t *);
+bool config_PrintAdvancedHelp (vlc_object_t *);
 
 int config_SortConfig (void);
 void config_UnsortConfig (void);
diff --git a/src/config/help.c b/src/config/help.c
index 5298f15ec3..663bf0630b 100644
--- a/src/config/help.c
+++ b/src/config/help.c
@@ -34,8 +34,10 @@
 #include <vlc_modules.h>
 #include <vlc_plugin.h>
 #include <vlc_charset.h>
+#include <vlc_aout.h>
 #include "modules/modules.h"
 #include "config/configuration.h"
+#include "audio_output/aout_internal.h"
 #include "libvlc.h"
 
 #if defined( _WIN32 )
@@ -59,6 +61,7 @@ static void Help (vlc_object_t *, const char *);
 static void Usage (vlc_object_t *, const char *);
 static void Version (void);
 static void ListModules (vlc_object_t *, bool);
+static void ListAoutDevices (vlc_object_t *);
 
 /**
  * Returns the console width or a best guess.
@@ -153,6 +156,28 @@ bool config_PrintHelp (vlc_object_t *obj)
     return false;
 }
 
+/**
+ * Checks for help command line options that need a valid libvlc instance
+ *
+ * Contrary to config_PrintHelp that is called in an early state (used to print
+ * a help message before libvlc initialisation can fail), this function need a
+ * fully initialized libvlc.
+ *
+ * If one help is found, print the corresponding text.
+ * \return true if a command line options caused some help message to be
+ * printed, false otherwise.
+ */
+bool config_PrintAdvancedHelp (vlc_object_t *obj)
+{
+    if (var_InheritBool (obj, "list-audio-devices"))
+    {
+        ListAoutDevices (obj);
+        return true;
+    }
+
+    return false;
+}
+
 /*****************************************************************************
  * Help: print program help
  *****************************************************************************
@@ -682,6 +707,41 @@ static void ListModules (vlc_object_t *p_this, bool b_verbose)
     PauseConsole();
 }
 
+static void ListAoutDevices (vlc_object_t *obj)
+{
+    ShowConsole();
+
+    var_Create (obj, "mute", VLC_VAR_BOOL);
+    audio_output_t *aout = aout_New(obj);
+    if (!aout)
+    {
+        printf("couldn't find any audio outputs\n");
+        return;
+    }
+    aout_owner_t *owner = aout_owner (aout);
+
+    char **ids, **names;
+    int count = aout_DevicesList(aout, &ids, &names);
+    if (count > 0)
+    {
+        printf("\nThe '%s' aout module has %d audio device%s:\n\n",
+               module_get_name(owner->module, false),
+               count, count > 1 ? "s" : "");
+        for (int i = 0; i < count; ++i)
+        {
+            printf("device[%d]:\n  id: [%s]\n  name: \"%s\"\n\n", i, ids[i],
+                   names[i]);
+            free(ids[i]);
+            free(names[i]);
+        }
+        free(ids);
+        free(names);
+    }
+    aout_Destroy(aout);
+
+    PauseConsole();
+}
+
 /*****************************************************************************
  * Version: print complete program version
  *****************************************************************************
diff --git a/src/libvlc-module.c b/src/libvlc-module.c
index 6d60e807af..cd52b77d87 100644
--- a/src/libvlc-module.c
+++ b/src/libvlc-module.c
@@ -2693,6 +2693,8 @@ vlc_module_begin ()
     N_("print a list of available modules")
 #define LIST_VERBOSE_TEXT \
     N_("print a list of available modules with extra detail")
+#define LIST_AOUT_DEVICE_TEXT \
+    N_("print a list of available audio devices")
 #define MODULE_TEXT \
     N_("print help on a specific module (can be combined with --advanced " \
        "and --help-verbose). Prefix the module name with = for strict " \
@@ -2725,6 +2727,8 @@ vlc_module_begin ()
     add_bool( "list-verbose", false, LIST_VERBOSE_TEXT, "",
               false )
         change_volatile ()
+    add_bool( "list-audio-devices", false, LIST_AOUT_DEVICE_TEXT, "", false )
+        change_volatile ()
     add_string( "module", NULL, MODULE_TEXT, "", false )
         change_short( 'p' )
         change_volatile ()
diff --git a/src/libvlc.c b/src/libvlc.c
index 34f24baf7f..879ba257b3 100644
--- a/src/libvlc.c
+++ b/src/libvlc.c
@@ -492,6 +492,12 @@ dbus_out:
         free( psz_val );
     }
 
+    if (config_PrintAdvancedHelp (VLC_OBJECT(p_libvlc)))
+    {
+        libvlc_InternalCleanup (p_libvlc);
+        exit(0);
+    }
+
     return VLC_SUCCESS;
 
 error:
-- 
2.11.0