policy-node: implement encoded audio passthrough

* also respect node.exclusive
* also send error to clients if a target node was not found
  or if it is not possible to link to it
* also allow dont-reconnect nodes to be handled normally
  the first time they appear, until they are linked once

modules/module-si-audio-adapter.c

@@ -238,6 +238,12 @@ si_audio_adapter_configure (WpSessionItem * item, WpProperties *p)
 
   self->node = g_object_ref (node);
 
+  wp_properties_set (si_props, "item.node.supports-encoded-fmts",
+      self->have_encoded ? "true" : "false");
+
+  wp_properties_set (si_props, "item.node.encoded-only",
+      self->encoded_only ? "true" : "false");
+
   wp_properties_set (si_props, "item.factory.name", SI_FACTORY_NAME);
   wp_session_item_set_properties (item, g_steal_pointer (&si_props));
   return TRUE;
@@ -578,7 +584,7 @@ si_audio_adapter_set_ports_format (WpSiAdapter * item, WpSpaPod *f,
   }
 
   /* build default format if NULL was given */
-  if (!format) {
+  if (!format && !g_strcmp0 (mode, "dsp")) {
     format = build_adapter_default_format (self, mode);
     g_return_if_fail (format);
   }

modules/module-si-standard-link.c

@@ -23,6 +23,7 @@ struct _WpSiStandardLink
   const gchar *out_item_port_context;
   const gchar *in_item_port_context;
   gboolean passive;
+  gboolean passthrough;
 
   /* activate */
   GPtrArray *node_links;
@@ -59,6 +60,7 @@ si_standard_link_reset (WpSessionItem * item)
   self->out_item_port_context = NULL;
   self->in_item_port_context = NULL;
   self->passive = FALSE;
+  self->passthrough = FALSE;
 
   WP_SESSION_ITEM_CLASS (si_standard_link_parent_class)->reset (item);
 }
@@ -108,11 +110,10 @@ si_standard_link_configure (WpSessionItem * item, WpProperties * p)
       "in.item.port.context");
 
   str = wp_properties_get (si_props, "passive");
-  if (str && sscanf(str, "%u", &self->passive) != 1)
-    return FALSE;
-  if (!str)
-    wp_properties_setf (si_props, "passive", "%u",
-        self->passive);
+  self->passive = str && pw_properties_parse_bool (str);
+
+  str = wp_properties_get (si_props, "passthrough");
+  self->passthrough = str && pw_properties_parse_bool (str);
 
   g_weak_ref_set(&self->out_item, out_item);
   g_weak_ref_set(&self->in_item, in_item);
@@ -340,23 +341,24 @@ on_main_adapter_ready (GObject *obj, GAsyncResult * res, gpointer p)
 
   si_out = WP_SI_ADAPTER (g_weak_ref_get (&self->out_item));
   si_in = WP_SI_ADAPTER (g_weak_ref_get (&self->in_item));
-
   g_return_if_fail (si_out);
   g_return_if_fail (si_in);
 
-  /* get format and mode */
-  other = si_out;
-  format = wp_si_adapter_get_ports_format (si_out, &mode);
-  if (!format) {
-    other = si_in;
-    format = wp_si_adapter_get_ports_format (si_in, &mode);
-  }
+  /* get the other adapter */
+  other = ((gpointer)obj == (gpointer)si_in) ? si_out : si_in;
 
-  g_return_if_fail (mode);
-  g_return_if_fail (format);
-  wp_si_adapter_set_ports_format (other, wp_spa_pod_ref (format),
-      g_strcmp0 (mode, "dsp") == 0 ? "dsp" : "convert",
-      on_adapters_ready, transition);
+  if (self->passthrough) {
+    wp_si_adapter_set_ports_format (other, NULL, "passthrough",
+        on_adapters_ready, transition);
+  } else {
+    format = wp_si_adapter_get_ports_format (WP_SI_ADAPTER (obj), &mode);
+    g_return_if_fail (mode);
+    g_return_if_fail (format);
+
+    wp_si_adapter_set_ports_format (other, wp_spa_pod_ref (format),
+        g_strcmp0 (mode, "dsp") == 0 ? "dsp" : "convert",
+        on_adapters_ready, transition);
+  }
 }
 
 static gboolean
@@ -366,7 +368,7 @@ ports_format_compatible (WpSpaPod *out_format, WpSpaPod *in_format,
   if (!out_format || !in_format || !out_mode || !in_mode)
     return FALSE;
   return wp_spa_pod_equal (out_format, in_format) &&
-      (g_strcmp0 (out_mode, "dsp") == 0) == (g_strcmp0 (in_mode, "dsp") == 0);
+      (g_strcmp0 (out_mode, "dsp") == 0) && (g_strcmp0 (in_mode, "dsp") == 0);
 }
 
 static void
@@ -378,6 +380,12 @@ configure_and_link (WpSiStandardLink *self, WpSiAdapter *main,
   g_autoptr (WpSpaPod) main_fmt = NULL;
   g_autoptr (WpSpaPod) other_fmt = NULL;
 
+  if (self->passthrough) {
+    wp_si_adapter_set_ports_format (main, NULL, "passthrough",
+        on_main_adapter_ready, transition);
+    return;
+  }
+
   main_fmt = wp_si_adapter_get_ports_format (main, &main_mode);
   other_fmt = wp_si_adapter_get_ports_format (other, &other_mode);
 

src/scripts/policy-node.lua

@@ -18,11 +18,13 @@ function parseBool(var)
   return var and (var == "true" or var == "1")
 end
 
-function createLink (si, si_target)
+function createLink (si, si_target, passthrough, exclusive)
   local out_item = nil
   local in_item = nil
+  local si_props = si.properties
+  local target_props = si_target.properties
 
-  if si.properties["item.node.direction"] == "output" then
+  if si_props["item.node.direction"] == "output" then
     -- playback
     out_item = si
     in_item = si_target
@@ -32,13 +34,14 @@ function createLink (si, si_target)
     out_item = si_target
   end
 
-  local passive = parseBool(si.properties["node.passive"]) or
-      parseBool(si_target.properties["node.passive"])
+  local passive = parseBool(si_props["node.passive"]) or
+      parseBool(target_props["node.passive"])
 
-  Log.info (string.format("link %s <-> %s passive:%s",
-      tostring(si.properties["node.name"]),
-      tostring(si_target.properties["node.name"]),
-      tostring(passive)))
+  Log.info (
+    string.format("link %s <-> %s passive:%s, passthrough:%s, exclusive:%s",
+      tostring(si_props["node.name"]),
+      tostring(target_props["node.name"]),
+      tostring(passive), tostring(passthrough), tostring(exclusive)))
 
   -- create and configure link
   local si_link = SessionItem ( "si-standard-link" )
@@ -46,6 +49,8 @@ function createLink (si, si_target)
     ["out.item"] = out_item,
     ["in.item"] = in_item,
     ["passive"] = passive,
+    ["passthrough"] = passthrough,
+    ["exclusive"] = exclusive,
     ["out.item.port.context"] = "output",
     ["in.item.port.context"] = "input",
     ["is.policy.item.link"] = true,
@@ -68,6 +73,47 @@ function createLink (si, si_target)
   end)
 end
 
+function isLinked(si_target)
+  local target_id = si_target.id
+  local linked = false
+  local exclusive = false
+
+  for l in links_om:iterate() do
+    local p = l.properties
+    local out_id = tonumber(p["out.item.id"])
+    local in_id = tonumber(p["in.item.id"])
+    linked = (out_id == target_id) or (in_id == target_id)
+    if linked then
+      exclusive = parseBool(p["exclusive"]) or parseBool(p["passthrough"])
+      break
+    end
+  end
+  return linked, exclusive
+end
+
+function canPassthrough (si, si_target)
+  -- both nodes must support encoded formats
+  if not parseBool(si.properties["item.node.supports-encoded-fmts"])
+      or not parseBool(si_target.properties["item.node.supports-encoded-fmts"]) then
+    return false
+  end
+
+  -- make sure that the nodes have at least one common non-raw format
+  local n1 = si:get_associated_proxy ("node")
+  local n2 = si_target:get_associated_proxy ("node")
+  for p1 in n1:iterate_params("EnumFormat") do
+    local p1p = p1:parse()
+    if p1p.properties.mediaSubtype ~= "raw" then
+      for p2 in n2:iterate_params("EnumFormat") do
+        if p1:filter(p2) then
+          return true
+        end
+      end
+    end
+  end
+  return false
+end
+
 function canLink (properties, si_target)
   local target_properties = si_target.properties
 
@@ -268,6 +314,8 @@ function checkLinkable(si)
   return true, si_props
 end
 
+si_flags = {}
+
 function handleLinkable (si)
   local valid, si_props = checkLinkable(si)
   if not valid then
@@ -283,28 +331,36 @@ function handleLinkable (si)
 
   Log.info (si, "handling item: " .. tostring(si_props["node.name"]))
 
-  -- get reconnect
-  local reconnect = not parseBool(si_props["node.dont-reconnect"])
-
-  -- find target
-  local si_target = findDefinedTarget (si_props)
-  if not si_target and not reconnect then
-    Log.info (si, "... destroy node")
-    local node = si:get_associated_proxy ("node")
-    node:request_destroy()
-    return
-  elseif not si_target and reconnect then
-    si_target = findUndefinedTarget (si_props)
+  -- prepare flags table
+  if not si_flags[si.id] then
+    si_flags[si.id] = {}
   end
+
+  -- get other important node properties
+  local reconnect = not parseBool(si_props["node.dont-reconnect"])
+  local exclusive = parseBool(si_props["node.exclusive"])
+  local must_passthrough = parseBool(si_props["item.node.encoded-only"])
+
+  -- find defined target
+  local si_target = findDefinedTarget(si_props)
+  local can_passthrough = si_target and canPassthrough(si, si_target)
+  if si_target and must_passthrough and not can_passthrough then
+    si_target = nil
+  end
+
+  -- find fallback target
   if not si_target then
-    Log.info (si, "... target not found")
-    return
+    si_target = findUndefinedTarget(si_props)
+    can_passthrough = si_target and canPassthrough(si, si_target)
+    if si_target and must_passthrough and not can_passthrough then
+      si_target = nil
+    end
   end
 
   -- Check if item is linked to proper target, otherwise re-link
   local si_link, si_peer = getSiLinkAndSiPeer (si, si_props)
   if si_link then
-    if si_peer and si_peer.id == si_target.id then
+    if si_peer and si_target and si_peer.id == si_target.id then
       Log.debug (si, "... already linked to proper target")
       return
     end
@@ -320,8 +376,53 @@ function handleLinkable (si)
     end
   end
 
-  -- create new link
-  createLink (si, si_target)
+  -- if the stream has dont-reconnect and was already linked before,
+  -- don't link it to a new target
+  if not reconnect and si_flags[si.id].was_handled then
+    si_target = nil
+  end
+
+  -- check target's availability
+  if si_target then
+    local target_is_linked, target_is_exclusive = isLinked(si_target)
+    if target_is_exclusive then
+      Log.info(si, "... target is linked exclusively")
+      si_target = nil
+    end
+
+    if target_is_linked then
+      if exclusive or must_passthrough then
+        Log.info(si, "... target is already linked, cannot link exclusively")
+        si_target = nil
+      else
+        -- disable passthrough, we can live without it
+        can_passthrough = false
+      end
+    end
+  end
+
+  if not si_target then
+    Log.info (si, "... target not found, reconnect:" .. tostring(reconnect))
+
+    local node = si:get_associated_proxy ("node")
+    if not reconnect then
+      Log.info (si, "... destroy node")
+      node:request_destroy()
+    end
+
+    local client_id = node.properties["client.id"]
+    if client_id then
+      local client = clients_om:lookup {
+          Constraint { "bound-id", "=", client_id, type = "gobject" }
+      }
+      if client then
+        client:send_error(node["bound-id"], -2, "no node available")
+      end
+    end
+  else
+    createLink (si, si_target, can_passthrough, exclusive)
+    si_flags[si.id].was_handled = true
+  end
 end
 
 function unhandleLinkable (si)
@@ -341,6 +442,8 @@ function unhandleLinkable (si)
       Log.info (silink, "... link removed")
     end
   end
+
+  si_flags[si.id] = nil
 end
 
 function rescan()
@@ -368,6 +471,8 @@ metadata_om = ObjectManager {
 
 endpoints_om = ObjectManager { Interest { type = "SiEndpoint" } }
 
+clients_om = ObjectManager { Interest { type = "client" } }
+
 linkables_om = ObjectManager {
   Interest {
     type = "SiLinkable",
@@ -441,5 +546,6 @@ end)
 
 metadata_om:activate()
 endpoints_om:activate()
+clients_om:activate()
 linkables_om:activate()
 links_om:activate()