speaker refactoring

[disorder] / server / speaker.c

diff --git a/server/speaker.c b/server/speaker.c
index 993441bccc9f58c708ae8fd133d77815cd624640..d3aea99deda84283ee27cfb857b8fa9c8b4e8ec4 100644 (file)
--- a/server/speaker.c
+++ b/server/speaker.c
@@ -220,6 +220,12 @@ struct speaker_backend {
    */
   int (*activate)(void);
 
+  /** @brief Play sound
+   * @param frames Number of frames to play
+   * @return Number of frames actually played
+   */
+  size_t (*play)(size_t frames);
+  
   /** @brief Deactivation
    *
    * Called to deactivate the sound device.  This is the inverse of
@@ -556,11 +562,12 @@ static void fork_cmd(void) {
 }
 
 static void play(size_t frames) {
-  size_t avail_bytes, write_bytes, written_frames;
+  size_t avail_frames, avail_bytes, write_bytes, written_frames;
   ssize_t written_bytes;
   struct rtp_header header;
   struct iovec vec[2];
 
+  /* Make sure the output device is activated */
   if(activate()) {
     if(playing)
       forceplay = frames;
@@ -583,43 +590,22 @@ static void play(size_t frames) {
   forceplay = 0;
   /* Figure out how many frames there are available to write */
   if(playing->start + playing->used > playing->size)
+    /* The ring buffer is currently wrapped, only play up to the wrap point */
     avail_bytes = playing->size - playing->start;
   else
+    /* The ring buffer is not wrapped, can play the lot */
     avail_bytes = playing->used;
+  avail_frames = avail_bytes / bpf;
+  /* Only play up to the requested amount */
+  if(avail_frames > frames)
+    avail_frames = frames;
+  if(!avail_frames)
+    return;
 
   switch(config->speaker_backend) {
 #if API_ALSA
   case BACKEND_ALSA: {
-    snd_pcm_sframes_t pcm_written_frames;
-    size_t avail_frames;
-    int err;
-
-    avail_frames = avail_bytes / bpf;
-    if(avail_frames > frames)
-      avail_frames = frames;
-    if(!avail_frames)
-      return;
-    pcm_written_frames = snd_pcm_writei(pcm,
-                                        playing->buffer + playing->start,
-                                        avail_frames);
-    D(("actually play %zu frames, wrote %d",
-       avail_frames, (int)pcm_written_frames));
-    if(pcm_written_frames < 0) {
-      switch(pcm_written_frames) {
-        case -EPIPE:                        /* underrun */
-          error(0, "snd_pcm_writei reports underrun");
-          if((err = snd_pcm_prepare(pcm)) < 0)
-            fatal(0, "error calling snd_pcm_prepare: %d", err);
-          return;
-        case -EAGAIN:
-          return;
-        default:
-          fatal(0, "error calling snd_pcm_writei: %d",
-                (int)pcm_written_frames);
-      }
-    }
-    written_frames = pcm_written_frames;
-    written_bytes = written_frames * bpf;
+    written_frames = backend->play(avail_frames);
     break;
   }
 #endif
@@ -754,6 +740,7 @@ static void play(size_t frames) {
   default:
     assert(!"reached");
   }
+  written_bytes = written_frames * bpf;
   /* written_bytes and written_frames had better both be set and correct by
    * this point */
   playing->start += written_bytes;
@@ -909,6 +896,33 @@ error:
   return -1;
 }
 
+/** @brief Play via ALSA */
+static size_t alsa_play(size_t frames) {
+  snd_pcm_sframes_t pcm_written_frames;
+  int err;
+  
+  pcm_written_frames = snd_pcm_writei(pcm,
+                                      playing->buffer + playing->start,
+                                      frames);
+  D(("actually play %zu frames, wrote %d",
+     frames, (int)pcm_written_frames));
+  if(pcm_written_frames < 0) {
+    switch(pcm_written_frames) {
+    case -EPIPE:                        /* underrun */
+      error(0, "snd_pcm_writei reports underrun");
+      if((err = snd_pcm_prepare(pcm)) < 0)
+        fatal(0, "error calling snd_pcm_prepare: %d", err);
+      return 0;
+    case -EAGAIN:
+      return 0;
+    default:
+      fatal(0, "error calling snd_pcm_writei: %d",
+            (int)pcm_written_frames);
+    }
+  } else
+    return pcm_written_frames;
+}
+
 /** @brief ALSA deactivation */
 static void alsa_deactivate(void) {
   if(pcm) {
@@ -933,6 +947,11 @@ static void command_init(void) {
   fork_cmd();
 }
 
+/** @brief Play to a subprocess */
+static size_t command_play(size_t frames) {
+  return frames;
+}
+
 /** @brief Command/network backend activation */
 static int generic_activate(void) {
   if(!ready) {
@@ -1014,6 +1033,11 @@ static void network_init(void) {
   }
 }
 
+/** @brief Play over the network */
+static size_t network_play(size_t frames) {
+  return frames;
+}
+
 /** @brief Table of speaker backends */
 static const struct speaker_backend backends[] = {
 #if API_ALSA
@@ -1022,6 +1046,7 @@ static const struct speaker_backend backends[] = {
     0,
     alsa_init,
     alsa_activate,
+    alsa_play,
     alsa_deactivate
   },
 #endif
@@ -1030,6 +1055,7 @@ static const struct speaker_backend backends[] = {
     FIXED_FORMAT,
     command_init,
     generic_activate,
+    command_play,
     0                                   /* deactivate */
   },
   {
@@ -1037,9 +1063,10 @@ static const struct speaker_backend backends[] = {
     FIXED_FORMAT,
     network_init,
     generic_activate,
+    network_play,
     0                                   /* deactivate */
   },
-  { -1, 0, 0, 0, 0 }
+  { -1, 0, 0, 0, 0, 0 }
 };
 
 int main(int argc, char **argv) {