airplay: fix some silly unsigned errors and handle network blackouts - release

components/squeezelite/decode_external.c

@@ -52,7 +52,7 @@ static raop_event_t	raop_state;
 static EXT_RAM_ATTR struct {
 	bool enabled;
 	int sum, count, win, errors[SYNC_WIN_RUN];
-	u32_t len;
+	s32_t len;
 	u32_t start_time, playtime;
 } raop_sync;
 
@@ -209,20 +209,21 @@ static bool raop_sink_cmd_handler(raop_event_t event, va_list args)
 				// how many ms have we really played
 				ms = now - output.updated + ((u64_t) (output.frames_played_dmp - output.device_frames) * 1000) / RAOP_SAMPLE_RATE;
 				error = ms - (now - raop_sync.start_time);
+				
 				LOG_INFO("backend played %u, desired %u, (delta:%d)", ms, now - raop_sync.start_time, ms - (now - raop_sync.start_time));
 			} else {	
+				u32_t level = _buf_used(outputbuf);
+				
 				// in how many ms will the most recent block play 
-				ms = ((u64_t) ((_buf_used(outputbuf) - raop_sync.len) / BYTES_PER_FRAME + output.device_frames + output.frames_in_process) * 1000) / RAOP_SAMPLE_RATE - (now - output.updated);
-				error = (raop_sync.playtime - now) - ms;
+				ms = (((s32_t)(level - raop_sync.len) / BYTES_PER_FRAME + output.device_frames + output.frames_in_process) * 10) / (RAOP_SAMPLE_RATE / 100) - (s32_t) (now - output.updated);
 				
-				// make sure impact of erroneous point is limited, but taken into account 
-				if (abs(error) > 1000) {
-					LOG_INFO("limiting erroneous sync point %d", error);
-					error = (error > 0) ? SYNC_WIN_RUN : -SYNC_WIN_RUN;
-				}
-								
-				LOG_DEBUG("head local:%u, remote:%u (delta:%d)", ms, raop_sync.playtime - now, error);
-				LOG_DEBUG("obuf:%u, sync_len:%u, devframes:%u, inproc:%u", _buf_used(outputbuf), raop_sync.len, output.device_frames, output.frames_in_process);
+				// when outputbuf is empty, it means we have a network black-out or something
+				error = level ? (raop_sync.playtime - now) - ms : 0;
+				
+				if (loglevel == lDEBUG || !level) {
+					LOG_INFO("head local:%d, remote:%d (delta:%d)", ms, raop_sync.playtime - now, error);
+					LOG_INFO("obuf:%u, sync_len:%u, devframes:%u, inproc:%u", _buf_used(outputbuf), raop_sync.len, output.device_frames, output.frames_in_process);
+				}	
 			}	
 			
 			// calculate sum, error and update sliding window
@@ -231,7 +232,10 @@ static bool raop_sink_cmd_handler(raop_event_t event, va_list args)
 			error = raop_sync.sum / min(raop_sync.count, raop_sync.win);
 			
 			// move to normal mode if possible
-			if (raop_sync.win == SYNC_WIN_START && raop_sync.count >= SYNC_WIN_START && abs(error) < 10) raop_sync.win = SYNC_WIN_RUN;
+			if (raop_sync.win == SYNC_WIN_START && raop_sync.count >= SYNC_WIN_START && abs(error) < 10) {
+				raop_sync.win = SYNC_WIN_RUN;
+				LOG_INFO("switching to slow sync mode %u", raop_sync.win);
+			}	
 
 			// wait till e have enough data or there is a strong deviation
 			if ((raop_sync.count >= raop_sync.win && abs(error) > 10) || (raop_sync.count >= SYNC_WIN_CHECK && abs(error) > 100)) { 
@@ -240,11 +244,11 @@ static bool raop_sink_cmd_handler(raop_event_t event, va_list args)
 				if (error < 0) {
 					output.skip_frames = -(error * RAOP_SAMPLE_RATE) / 1000;
 					output.state = OUTPUT_SKIP_FRAMES;					
-					LOG_INFO("skipping %u frames", output.skip_frames);
+					LOG_INFO("skipping %u frames (count:%d)", output.skip_frames, raop_sync.count);
 				} else {
 					output.pause_frames = (error * RAOP_SAMPLE_RATE) / 1000;
 					output.state = OUTPUT_PAUSE_FRAMES;
-					LOG_INFO("pausing for %u frames", output.pause_frames);
+					LOG_INFO("pausing for %u frames (count: %d)", output.pause_frames, raop_sync.count);
 				}
 
 				// reset sliding window