Add get_volume and set_volume methods

This uses the global volume for the audio/mixer device. This isn't
ideal, but to my understanding follows what the alsa and oss plugins
do as well. Audacious already provides a software volume control in
Settings -> Audio, which despite saying "not recommended," doesn't
seem to have any issues.

TODO

@@ -1,9 +1,5 @@
-* Figure out how to manage get_volume and set_volume
-  * Should it be global? Does (audio_info_t)info.play.gain
-    refer to the global mixer or just the track (i'm guessing
-    from the manpage that it's global?)
-* Find out if/how audio(4) supports 24-bit linear PCM
-  * Audacious supports two methods-- one is 3-byte, the other
-    is padded 4-byte. I'm guessing audio(4) doesn't support
-    both, but who knows
-* Clean up the code in terms of formatting/layout
+* Determine if audio open/close should happen in open_audio
+  and close_audio
+* Support 24-bit LPCM -> 32-bit
+* Create a settings panel so users can select their output
+  device

src/netbsdout.cc

@@ -13,7 +13,6 @@
 #include <libaudcore/ringbuf.h>
 #include <libaudcore/runtime.h>
 
-
 class NetBSDOutput : public OutputPlugin
 {
 public:
@@ -34,19 +33,16 @@ public:
     void close_audio ();
 
     int write_audio (const void * data, int size);
+    void pause (bool pause);
 
     void period_wait ();
-
-    void drain ();
+    int get_delay ();
 
     void set_volume(StereoVolume volume);
     StereoVolume get_volume();
 
-    int get_delay ();
-
-    void pause (bool pause);
-
     void flush ();
+    void drain ();
 };
 
 __attribute__((visibility("default"))) NetBSDOutput aud_plugin_instance;
@@ -54,7 +50,7 @@ __attribute__((visibility("default"))) NetBSDOutput aud_plugin_instance;
 static String audio_path;
 static int audio_fd;
 
-static bool audio_paused, audio_prebuffer, audio_flushed;
+static bool audio_paused, audio_flushed;
 
 static pthread_mutex_t nbout_mutex = PTHREAD_MUTEX_INITIALIZER;
 static pthread_cond_t nbout_cond = PTHREAD_COND_INITIALIZER;
@@ -101,7 +97,7 @@ NetBSDOutput::init ()
     audio_fd = open (audio_path, O_WRONLY);
 
     if (audio_fd == -1) {
-        AUDERR ("Failed to open %s: %s.\n", audio_path, strerror (errno));
+        AUDERR ("Failed to open %s: %s.\n", (const char *) audio_path, strerror (errno));
         return false;
     }
 
@@ -114,16 +110,21 @@ NetBSDOutput::cleanup ()
     close (audio_fd);
 }
 
+/*
+ * Converts the format libaudcore provides to something usable
+ * in audio_info_t, then passes along the information to the
+ * audio device.
+ */
 bool
 NetBSDOutput::open_audio (int format,
                           int rate,
                           int chans,
                           String & error)
 {
-    // TODO: 
+    /* TODO: Use FMT_S24_* or FMT_S24_3* */
     audio_info_t info;
     int props;
-    // Audacious->NetBSD format table
+    /* Audacious->NetBSD format table */
     static const struct fmt_conv fmt_table[] = {
         {FMT_S8, AUDIO_ENCODING_SLINEAR, 8},
         {FMT_U8, AUDIO_ENCODING_ULINEAR, 8},
@@ -141,18 +142,19 @@ NetBSDOutput::open_audio (int format,
     if (ioctl (audio_fd, AUDIO_GETPROPS, & props) == -1) {
         error = String (str_printf
             ("Failed to get audio properties on %s: %s.",
-            audio_path, strerror (errno)));
+            (const char *) audio_path, strerror (errno)));
         return false;
     }
 
-    if (props | AUDIO_PROP_PLAYBACK != AUDIO_PROP_PLAYBACK) {
+    if ((props | AUDIO_PROP_PLAYBACK) != AUDIO_PROP_PLAYBACK) {
         error = String (str_printf
             ("Device %s does not support playback.",
-            audio_path));
+            (const char *) audio_path));
     }
 
     AUDIO_INITINFO (&info);
 
+    /* Loop to find the right format, if it's supported */
     for (auto & conv : fmt_table) {
         if (conv.aud_format == format) {
             cur_format = conv;
@@ -165,17 +167,18 @@ NetBSDOutput::open_audio (int format,
         return false;
     }
 
-    info.play.channels = chans;
     info.play.encoding = cur_format.encoding;
     info.play.precision = cur_format.bits;
+
+    /* Channels and sample rate are straightforward, at least */
+    info.play.channels = chans;
     info.play.sample_rate = rate;
     info.mode = AUMODE_PLAY;
 
-
     if (ioctl (audio_fd, AUDIO_SETINFO, & info) == -1) {
         error = String (str_printf
              ("Failed to set track info on %s: %s.\n",
-             audio_path, strerror (errno)));
+             (const char *) audio_path, strerror (errno)));
         return false;
     }
 
@@ -185,7 +188,7 @@ NetBSDOutput::open_audio (int format,
 void
 NetBSDOutput::close_audio ()
 {
-    AUDDBG ("close_audio is a stub!\n"); // XXX
+    AUDDBG ("close_audio is a stub!\n"); /* XXX */
 }
 
 int
@@ -235,8 +238,7 @@ NetBSDOutput::period_wait ()
 void
 NetBSDOutput::pause (bool pause)
 {
-    int res, len;
-    audio_info_t info;
+    int res;
 
     AUDDBG ("Setting pause = %s.\n", pause ? "true" : "false");
 
@@ -330,14 +332,32 @@ NetBSDOutput::flush ()
 StereoVolume
 NetBSDOutput::get_volume ()
 {
-    // too noisy, even for debug...
-    // AUDDBG ("get_volume: Stub!\n");
+    audio_info_t info;
+    int aud_vol;
 
-    return {100, 100}; // XXX
+    if (ioctl (audio_fd, AUDIO_GETINFO, & info) != 0) {
+        AUDERR ("Unable to get volume: %s.\n", strerror (errno));
+        return { 0, 0 };
+    }
+
+    aud_vol = aud::rescale ((int)info.play.gain - AUDIO_MIN_GAIN,
+                            AUDIO_MAX_GAIN - AUDIO_MIN_GAIN,
+                            100);
+
+    return { aud_vol, aud_vol };
 }
 
 void
 NetBSDOutput::set_volume (StereoVolume volume)
 {
-    AUDDBG ("set_volume: Stub!\n"); // XXX
+    audio_info_t info;
+
+    AUDIO_INITINFO (& info);
+    info.play.gain = aud::rescale (aud::max
+        (volume.left, volume.right), 100,
+        AUDIO_MAX_GAIN) + AUDIO_MIN_GAIN;
+
+    if (ioctl(audio_fd, AUDIO_SETINFO, & info) != 0) {
+        AUDERR ("Unable to set volume: %s.\n", strerror (errno));
+    }
 }