rdp: Add audio support

Allow the front end to register audio setup and teardown functions. These
functions should use FreeRDP's rdpsnd_server_context or
audin_server_context and set up their own handler threads.

The backend remains mostly ignorant to any audio details beyond setting up
and tearing down.

Signed-off-by: Derek Foreman <derek.foreman@collabora.com>

include/libweston/backend-rdp.h

@@ -57,6 +57,11 @@ weston_rdp_output_get_api(struct weston_compositor *compositor)
 
 #define WESTON_RDP_BACKEND_CONFIG_VERSION 2
 
+typedef void *(*rdp_audio_in_setup)(struct weston_compositor *c, void *vcm);
+typedef void (*rdp_audio_in_teardown)(void *audio_private);
+typedef void *(*rdp_audio_out_setup)(struct weston_compositor *c, void *vcm);
+typedef void (*rdp_audio_out_teardown)(void *audio_private);
+
 struct weston_rdp_backend_config {
 	struct weston_backend_config base;
 	char *bind_address;
@@ -70,6 +75,10 @@ struct weston_rdp_backend_config {
 	bool remotefx_codec;
 	int external_listener_fd;
 	int refresh_rate;
+	rdp_audio_in_setup audio_in_setup;
+	rdp_audio_in_teardown audio_in_teardown;
+	rdp_audio_out_setup audio_out_setup;
+	rdp_audio_out_teardown audio_out_teardown;
 };
 
 #ifdef  __cplusplus

libweston/backend-rdp/rdp.c

@@ -668,10 +668,14 @@ out_error_stream:
 static void
 rdp_peer_context_free(freerdp_peer* client, RdpPeerContext* context)
 {
+	struct rdp_backend *b;
 	unsigned i;
+
 	if (!context)
 		return;
 
+	b = context->rdpBackend;
+
 	wl_list_remove(&context->item.link);
 
 	for (i = 0; i < ARRAY_LENGTH(context->events); i++) {
@@ -679,6 +683,12 @@ rdp_peer_context_free(freerdp_peer* client, RdpPeerContext* context)
 			wl_event_source_remove(context->events[i]);
 	}
 
+	if (context->audio_in_private)
+		b->audio_in_teardown(context->audio_in_private);
+
+	if (context->audio_out_private)
+		b->audio_out_teardown(context->audio_out_private);
+
 	rdp_clipboard_destroy(context);
 
 	if (context->vcm)
@@ -936,11 +946,22 @@ xf_peer_activate(freerdp_peer* client)
 		settings->CompressionEnabled = FALSE;
 	}
 
-	if (settings->RedirectClipboard) {
+	settings->AudioPlayback = b->audio_out_setup && b->audio_out_teardown;
+	settings->AudioCapture = b->audio_in_setup && b->audio_in_teardown;
+
+	if (settings->RedirectClipboard ||
+	    settings->AudioPlayback ||
+	    settings->AudioCapture) {
 		if (!peerCtx->vcm) {
-			weston_log("Virtual channel is required for clipboard\n");
+			weston_log("Virtual channel is required for clipboard, audio playback/capture\n");
 			goto error_exit;
 		}
+		/* Audio setup will return NULL on failure, and we'll proceed without audio */
+		if (settings->AudioPlayback)
+			peerCtx->audio_out_private = b->audio_out_setup(b->compositor, peerCtx->vcm);
+
+		if (settings->AudioCapture)
+			peerCtx->audio_in_private = b->audio_in_setup(b->compositor, peerCtx->vcm);
 	}
 
 	if (output->base.width != (int)settings->DesktopWidth ||
@@ -1043,6 +1064,12 @@ error_exit:
 
 	rdp_clipboard_destroy(peerCtx);
 
+	if (settings->AudioPlayback && peerCtx->audio_out_private)
+		b->audio_out_teardown(peerCtx->audio_out_private);
+
+	if (settings->AudioCapture && peerCtx->audio_in_private)
+		b->audio_in_teardown(peerCtx->audio_in_private);
+
 	return FALSE;
 }
 
@@ -1585,6 +1612,10 @@ rdp_backend_create(struct weston_compositor *compositor,
 	b->no_clients_resize = config->no_clients_resize;
 	b->force_no_compression = config->force_no_compression;
 	b->remotefx_codec = config->remotefx_codec;
+	b->audio_in_setup = config->audio_in_setup;
+	b->audio_in_teardown = config->audio_in_teardown;
+	b->audio_out_setup = config->audio_out_setup;
+	b->audio_out_teardown = config->audio_out_teardown;
 
 	b->debug = weston_compositor_add_log_scope(compositor,
 						   "rdp-backend",
@@ -1729,6 +1760,10 @@ config_init_to_defaults(struct weston_rdp_backend_config *config)
 	config->remotefx_codec = true;
 	config->external_listener_fd = -1;
 	config->refresh_rate = RDP_DEFAULT_FREQ;
+	config->audio_in_setup = NULL;
+	config->audio_in_teardown = NULL;
+	config->audio_out_setup = NULL;
+	config->audio_out_teardown = NULL;
 }
 
 WL_EXPORT int

libweston/backend-rdp/rdp.h

@@ -92,6 +92,11 @@ struct rdp_backend {
 	int external_listener_fd;
 	int rdp_monitor_refresh_rate;
 	pid_t compositor_tid;
+
+        rdp_audio_in_setup audio_in_setup;
+        rdp_audio_in_teardown audio_in_teardown;
+        rdp_audio_out_setup audio_out_setup;
+        rdp_audio_out_teardown audio_out_teardown;
 };
 
 enum peer_item_flags {
@@ -149,6 +154,9 @@ struct rdp_peer_context {
 	/* Clipboard support */
 	CliprdrServerContext *clipboard_server_context;
 
+	void *audio_in_private;
+	void *audio_out_private;
+
 	struct rdp_clipboard_data_source *clipboard_client_data_source;
 	struct rdp_clipboard_data_source *clipboard_inflight_client_data_source;