libobs: Report lost frame count due to rendering lag

This has been missing for a bit too long, and should make it
easier/faster to diagnose issues users might be having.

libobs/obs-internal.h

@@ -242,6 +242,8 @@ struct obs_core_video {
 	uint64_t                        video_time;
 	video_t                         *video;
 	pthread_t                       video_thread;
+	uint32_t                        total_frames;
+	uint32_t                        lagged_frames;
 	bool                            thread_initialized;
 
 	bool                            gpu_conversion;
@@ -631,6 +633,8 @@ struct obs_output {
 	os_event_t                      *reconnect_stop_event;
 	volatile bool                   reconnect_thread_active;
 
+	uint32_t                        starting_drawn_count;
+	uint32_t                        starting_lagged_count;
 	uint32_t                        starting_frame_count;
 	uint32_t                        starting_skipped_frame_count;
 

libobs/obs-output.c

@@ -190,6 +190,8 @@ bool obs_output_actual_start(obs_output_t *output)
 			video_output_get_total_frames(output->video);
 		output->starting_skipped_frame_count =
 			video_output_get_skipped_frames(output->video);
+		output->starting_drawn_count = obs->video.total_frames;
+		output->starting_lagged_count = obs->video.lagged_frames;
 	}
 
 	if (output->delay_restart_refs)
@@ -222,35 +224,52 @@ bool obs_output_start(obs_output_t *output)
 
 static void log_frame_info(struct obs_output *output)
 {
+	struct obs_core_video *video = &obs->video;
+
 	uint32_t video_frames  = video_output_get_total_frames(output->video);
 	uint32_t video_skipped = video_output_get_skipped_frames(output->video);
 
 	uint32_t total   = video_frames  - output->starting_frame_count;
 	uint32_t skipped = video_skipped - output->starting_skipped_frame_count;
 
+	uint32_t drawn  = video->total_frames - output->starting_drawn_count;
+	uint32_t lagged = video->lagged_frames - output->starting_lagged_count;
+
 	int dropped = obs_output_get_frames_dropped(output);
 
-	double percentage_skipped = (double)skipped / (double)total * 100.0;
+	double percentage_skipped = 0.0f;
+	double percentage_lagged = 0.0f;
+	double percentage_dropped = 0.0f;
+
+	if (total) {
+		percentage_skipped = (double)skipped / (double)total * 100.0;
+		percentage_dropped = (double)dropped / (double)total * 100.0;
+	}
+	if (drawn)
+		percentage_lagged = (double)lagged  / (double)drawn * 100.0;
 
 	blog(LOG_INFO, "Output '%s': stopping", output->context.name);
-	blog(LOG_INFO, "Output '%s': Total frames: %"PRIu32,
+	blog(LOG_INFO, "Output '%s': Total encoded frames: %"PRIu32,
 			output->context.name, total);
+	blog(LOG_INFO, "Output '%s': Total drawn frames: %"PRIu32,
+			output->context.name, drawn);
 
-	if (total)
-		blog(LOG_INFO, "Output '%s': Number of skipped frames: "
-				"%"PRIu32" (%g%%)",
+	if (total && skipped)
+		blog(LOG_INFO, "Output '%s': Number of skipped frames due "
+				"to encoding lag: %"PRIu32" (%0.1f%%)",
 				output->context.name,
 				skipped, percentage_skipped);
-
-	if (dropped) {
-		double percentage_dropped;
-		percentage_dropped = (double)dropped / (double)total * 100.0;
-
-		blog(LOG_INFO, "Output '%s': Number of dropped frames: "
-				"%d (%g%%)",
+	if (drawn && lagged)
+		blog(LOG_INFO, "Output '%s': Number of lagged frames due "
+				"to rendering lag/stalls: %"PRIu32" (%0.1f%%)",
+				output->context.name,
+				lagged, percentage_lagged);
+	if (total && dropped)
+		blog(LOG_INFO, "Output '%s': Number of dropped frames due "
+				"to insufficient bandwidth/connection stalls: "
+				"%d (%0.1f%%)",
 				output->context.name,
 				dropped, percentage_dropped);
-	}
 }
 
 void obs_output_actual_stop(obs_output_t *output, bool force)

libobs/obs-video.c

@@ -528,6 +528,9 @@ static inline void video_sleep(struct obs_core_video *video,
 		*p_time = cur_time + interval_ns * count;
 	}
 
+	video->total_frames += count;
+	video->lagged_frames += count - 1;
+
 	vframe_info.timestamp = cur_time;
 	vframe_info.count = count;
 	circlebuf_push_back(&video->vframe_info_buffer, &vframe_info,