Video source reuse API

coreapi/linphonecall.c

@@ -1108,7 +1108,7 @@ const LinphoneCallParams * linphone_call_get_current_params(LinphoneCall *call){
 const LinphoneCallParams * linphone_call_get_remote_params(LinphoneCall *call){
 	if (call->op){
 		LinphoneCallParams *cp;
-        SalMediaDescription *md;
+		SalMediaDescription *md;
 		if (call->remote_params != NULL) linphone_call_params_unref(call->remote_params);
 		cp = call->remote_params = linphone_call_params_new();
 		md=sal_call_get_remote_media_description(call->op);
@@ -2025,12 +2025,17 @@ static void linphone_call_start_video_stream(LinphoneCall *call, const char *cna
 	int used_pt=-1;
 	char rtcp_tool[128]={0};
 	const SalStreamDescription *vstream;
+	MSFilter* source = NULL;
+	bool_t reused_preview = FALSE;
 
 	snprintf(rtcp_tool,sizeof(rtcp_tool)-1,"%s-%s",linphone_core_get_user_agent_name(),linphone_core_get_user_agent_version());
 
 	/* shutdown preview */
 	if (lc->previewstream!=NULL) {
-		video_preview_stop(lc->previewstream);
+
+		if( lc->video_conf.reuse_preview_source == FALSE) video_preview_stop(lc->previewstream);
+		else source = video_preview_stop_reuse_source(lc->previewstream);
+
 		lc->previewstream=NULL;
 	}
 
@@ -2105,16 +2110,31 @@ static void linphone_call_start_video_stream(LinphoneCall *call, const char *cna
 				video_stream_set_device_rotation(call->videostream, lc->device_rotation);
 				video_stream_set_rtcp_information(call->videostream, cname, rtcp_tool);
 				video_stream_set_freeze_on_error(call->videostream, lp_config_get_int(lc->config, "video", "freeze_on_error", 0));
-				video_stream_start(call->videostream,
-					call->video_profile, rtp_addr, vstream->rtp_port,
-					rtcp_addr,
-					linphone_core_rtcp_enabled(lc) ? (vstream->rtcp_port ? vstream->rtcp_port : vstream->rtp_port+1) : 0,
-					used_pt, linphone_core_get_video_jittcomp(lc), cam);
+				if( lc->video_conf.reuse_preview_source && source ){
+					ms_message("video_stream_start_with_source kept: %p", source);
+					video_stream_start_with_source(call->videostream,
+												   call->video_profile, rtp_addr, vstream->rtp_port,
+												   rtcp_addr,
+												   linphone_core_rtcp_enabled(lc) ? (vstream->rtcp_port ? vstream->rtcp_port : vstream->rtp_port+1) : 0,
+												   used_pt, linphone_core_get_video_jittcomp(lc), cam, source);
+					reused_preview = TRUE;
+				} else {
+					video_stream_start(call->videostream,
+									   call->video_profile, rtp_addr, vstream->rtp_port,
+									   rtcp_addr,
+									   linphone_core_rtcp_enabled(lc) ? (vstream->rtcp_port ? vstream->rtcp_port : vstream->rtp_port+1) : 0,
+									   used_pt, linphone_core_get_video_jittcomp(lc), cam);
+				}
 			}
 		}else ms_warning("No video stream accepted.");
 	}else{
 		ms_message("No valid video stream defined.");
 	}
+	if( reused_preview == FALSE && source != NULL ){
+		/* destroy not-reused source filter */
+		ms_warning("Video preview (%p) not reused: destroying it.", source);
+		ms_filter_destroy(source);
+	}
 #endif
 }
 

coreapi/linphonecore.c

@@ -692,7 +692,7 @@ static void build_video_devices_table(LinphoneCore *lc){
 
 static void video_config_read(LinphoneCore *lc){
 #ifdef VIDEO_ENABLED
-	int capture, display, self_view;
+	int capture, display, self_view, reuse_source;
 	int automatic_video=1;
 #endif
 	const char *str;
@@ -721,12 +721,14 @@ static void video_config_read(LinphoneCore *lc){
 	capture=lp_config_get_int(lc->config,"video","capture",1);
 	display=lp_config_get_int(lc->config,"video","display",1);
 	self_view=lp_config_get_int(lc->config,"video","self_view",1);
+	reuse_source=lp_config_get_int(lc->config,"video","reuse_source",0);
 	vpol.automatically_initiate=lp_config_get_int(lc->config,"video","automatically_initiate",automatic_video);
 	vpol.automatically_accept=lp_config_get_int(lc->config,"video","automatically_accept",automatic_video);
 	linphone_core_enable_video_capture(lc, capture);
 	linphone_core_enable_video_display(lc, display);
 	linphone_core_enable_video_preview(lc,lp_config_get_int(lc->config,"video","show_local",0));
 	linphone_core_enable_self_view(lc,self_view);
+	linphone_core_enable_video_source_reuse(lc, reuse_source);
 	linphone_core_set_video_policy(lc,&vpol);
 #endif
 }
@@ -4593,6 +4595,18 @@ void linphone_core_enable_video_display(LinphoneCore *lc, bool_t enable) {
 	reapply_network_bandwidth_settings(lc);
 }
 
+void linphone_core_enable_video_source_reuse(LinphoneCore* lc, bool_t enable){
+#ifndef VIDEO_ENABLED
+	if (enable == TRUE) {
+		ms_warning("Cannot enable video display, this version of linphone was built without video support.");
+	}
+#endif
+	lc->video_conf.reuse_preview_source = enable;
+	if( linphone_core_ready(lc) ){
+		lp_config_set_int(lc->config, "video", "reuse_source", lc->video_conf.reuse_preview_source);
+	}
+}
+
 bool_t linphone_core_video_capture_enabled(LinphoneCore *lc) {
 	return lc->video_conf.capture;
 }

coreapi/linphonecore.h

@@ -2486,6 +2486,24 @@ LINPHONE_PUBLIC void linphone_core_enable_video_capture(LinphoneCore *lc, bool_t
 **/
 LINPHONE_PUBLIC void linphone_core_enable_video_display(LinphoneCore *lc, bool_t enable);
 
+
+/**
+ * Enable or disable video source reuse when switching from preview to actual video call.
+ *
+ * This source reuse is useful when you always display the preview, even before calls are initiated.
+ * By keeping the video source for the transition to a real video call, you will smooth out the
+ * source close/reopen cycle.
+ *
+ * This function does not have any effect durfing calls. It just indicates the #LinphoneCore to
+ * initiate future calls with video source reuse or not.
+ * Also, at the end of a video call, the source will be closed whatsoever for now.
+ * @param[in] lc #LinphoneCore object
+ * @param[in] enable TRUE to enable video source reuse. FALSE to disable it for subsequent calls.
+ * @ingroup media_parameters
+ *
+ */
+LINPHONE_PUBLIC void linphone_core_enable_video_source_reuse(LinphoneCore* lc, bool_t enable);
+
 /**
  * Tells whether video capture is enabled.
  * @param[in] lc #LinphoneCore object.

coreapi/private.h

@@ -632,6 +632,7 @@ typedef struct video_config{
 	bool_t show_local;
 	bool_t display;
 	bool_t selfview; /*during calls*/
+	bool_t reuse_preview_source;
 }video_config_t;
 
 typedef struct ui_config