[raop] Use GET_PARAMETER of volume to keep connection alive and get speaker volume

src/outputs/raop.c

@@ -327,7 +327,7 @@ static struct event *flush_timer;
 
 /* Keep-alive timer - hack for ATV's with tvOS 10 */
 static struct event *keep_alive_timer;
-static struct timeval keep_alive_tv = { 60, 0 };
+static struct timeval keep_alive_tv = { 30, 0 };
 
 /* Sessions */
 static struct raop_session *sessions;
@@ -1443,6 +1443,56 @@ raop_send_req_set_parameter(struct raop_session *rs, struct evbuffer *evbuf, cha
   return 0;
 }
 
+static int
+raop_send_req_get_parameter(struct raop_session *rs, struct evbuffer *evbuf, char *ctype, char *rtpinfo, evrtsp_req_cb cb)
+{
+  struct evrtsp_request *req;
+  int ret;
+
+  req = evrtsp_request_new(cb, rs);
+  if (!req)
+    {
+      DPRINTF(E_LOG, L_RAOP, "Could not create RTSP request for GET_PARAMETER\n");
+
+      return -1;
+    }
+
+  ret = evbuffer_add_buffer(req->output_buffer, evbuf);
+  if (ret < 0)
+    {
+      DPRINTF(E_LOG, L_RAOP, "Out of memory for GET_PARAMETER payload\n");
+
+      evrtsp_request_free(req);
+      return -1;
+    }
+
+  ret = raop_add_headers(rs, req, EVRTSP_REQ_GET_PARAMETER);
+  if (ret < 0)
+    {
+      evrtsp_request_free(req);
+      return -1;
+    }
+
+  evrtsp_add_header(req->output_headers, "Content-Type", ctype);
+
+  if (rtpinfo)
+    evrtsp_add_header(req->output_headers, "RTP-Info", rtpinfo);
+
+  ret = evrtsp_make_request(rs->ctrl, req, EVRTSP_REQ_GET_PARAMETER, rs->session_url);
+  if (ret < 0)
+    {
+      DPRINTF(E_LOG, L_RAOP, "Could not make GET_PARAMETER request\n");
+
+      return -1;
+    }
+
+  rs->reqs_in_flight++;
+
+  evrtsp_connection_set_closecb(rs->ctrl, NULL, NULL);
+
+  return 0;
+}
+
 static int
 raop_send_req_record(struct raop_session *rs, evrtsp_req_cb cb)
 {
@@ -2376,8 +2426,25 @@ raop_metadata_send(void *metadata, uint64_t rtptime, uint64_t offset, int startu
 }
 
 /* Volume handling */
+static int
+raop_volume_to_pct(float raop_volume)
+{
+  int volume;
+
+  /* RAOP volume
+   *  -144.0 is off
+   *  -30.0 - 0 maps to 0 - 100
+   */
+  if (raop_volume > -30.0 && raop_volume <= 0.0)
+    volume = (int)(100.0 * raop_volume / 30.0 + 100.0);
+  else
+    volume = 0;
+
+  return volume;
+}
+
 static float
-raop_volume_convert(int volume, char *name)
+raop_volume_from_pct(int volume, char *name)
 {
   float raop_volume;
   cfg_t *airplay;
@@ -2391,7 +2458,7 @@ raop_volume_convert(int volume, char *name)
 
   if ((max_volume < 1) || (max_volume > RAOP_CONFIG_MAX_VOLUME))
     {
-      DPRINTF(E_LOG, L_RAOP, "Config has bad max_volume (%d) for device %s, using default instead\n", max_volume, name);
+      DPRINTF(E_LOG, L_RAOP, "Config has bad max_volume (%d) for device '%s', using default instead\n", max_volume, name);
 
       max_volume = RAOP_CONFIG_MAX_VOLUME;
     }
@@ -2423,7 +2490,7 @@ raop_set_volume_internal(struct raop_session *rs, int volume, evrtsp_req_cb cb)
       return -1;
     }
 
-  raop_volume = raop_volume_convert(volume, rs->devname);
+  raop_volume = raop_volume_from_pct(volume, rs->devname);
 
   /* Don't let locales get in the way here */
   /* We use -%d and -(int)raop_volume so -0.3 won't become 0.3 */
@@ -2447,6 +2514,36 @@ raop_set_volume_internal(struct raop_session *rs, int volume, evrtsp_req_cb cb)
   return ret;
 }
 
+static int
+raop_get_volume_internal(struct raop_session *rs, evrtsp_req_cb cb)
+{
+  struct evbuffer *evbuf;
+  int ret;
+
+  evbuf = evbuffer_new();
+  if (!evbuf)
+    {
+      DPRINTF(E_LOG, L_RAOP, "Could not allocate evbuffer for volume payload\n");
+      return -1;
+    }
+
+  ret = evbuffer_add_printf(evbuf, "volume\n");
+  if (ret < 0)
+    {
+      DPRINTF(E_LOG, L_RAOP, "Out of memory for GET_PARAMETER payload (volume)\n");
+      evbuffer_free(evbuf);
+      return -1;
+    }
+
+  ret = raop_send_req_get_parameter(rs, evbuf, "text/parameters", NULL, cb);
+  if (ret < 0)
+    DPRINTF(E_LOG, L_RAOP, "Could not send GET_PARAMETER request for volume\n");
+
+  evbuffer_free(evbuf);
+
+  return ret;
+}
+
 static void
 raop_cb_set_volume(struct evrtsp_request *req, void *arg)
 {
@@ -2549,25 +2646,45 @@ static void
 raop_cb_keep_alive(struct evrtsp_request *req, void *arg)
 {
   struct raop_session *rs = arg;
+  char *body;
+  float raop_volume;
 
   rs->reqs_in_flight--;
 
   if (!req)
-    goto error;
-
-  if (req->response_code != RTSP_OK)
     {
-      DPRINTF(E_LOG, L_RAOP, "SET_PARAMETER request failed for keep alive: %d %s\n", req->response_code, req->response_code_line);
+      DPRINTF(E_LOG, L_RAOP, "No reply from '%s' to our keep alive request, hanging up\n", rs->devname);
-      goto error;
+      raop_session_failure(rs);
+      return;
     }
 
   if (!rs->reqs_in_flight)
     evrtsp_connection_set_closecb(rs->ctrl, raop_rtsp_close_cb, rs);
 
+  if (req->response_code != RTSP_OK)
+    {
+      DPRINTF(E_LOG, L_RAOP, "Keep alive GET_PARAMETER request to '%s' failed: %d %s\n", rs->devname, req->response_code, req->response_code_line);
       return;
+    }
 
- error:
+  evbuffer_add(req->input_buffer, "", 1); // NULL-terminate
-  raop_session_failure(rs);
+
+  body = (char *)evbuffer_pullup(req->input_buffer, -1);
+  if (!body || strncmp(body, "volume: ", strlen("volume: ")) != 0)
+    {
+      DPRINTF(E_LOG, L_RAOP, "Invalid response from '%s' to keep alive request: '%s'\n", rs->devname, body);
+      return;
+    }
+
+  raop_volume = atof(strchr(body, ':') + 2);
+
+  rs->volume = raop_volume_to_pct(raop_volume);
+
+  DPRINTF(E_DBG, L_RAOP, "GET_PARAMETER request to '%s' returned volume %f (%d)\n", rs->devname, raop_volume, rs->volume);
+
+  evtimer_add(keep_alive_timer, &keep_alive_tv);
+
+  return;
 }
 
 static void
@@ -2632,16 +2749,14 @@ raop_keep_alive_timer_cb(int fd, short what, void *arg)
 
   for (rs = sessions; rs; rs = rs->next)
     {
-      if (!rs->keep_alive)
+//      if (!rs->keep_alive)
-	continue;
+//	continue;
 
       if (!(rs->state & RAOP_STATE_F_CONNECTED))
 	continue;
 
-      raop_set_volume_internal(rs, rs->volume, raop_cb_keep_alive);
+      raop_get_volume_internal(rs, raop_cb_keep_alive);
     }
-
-  evtimer_add(keep_alive_timer, &keep_alive_tv);
 }
 
 static int