fix: implement strict Ogg page alignment and prevent duplicate headers to resolve CRC mismatch errors

Author: Datanoise

relay/relay.go

@@ -323,16 +323,28 @@ func (s *Stream) Subscribe(id string, burstSize int) (int64, chan struct{}) {
 		start = 0
 	}
 
-	// For Ogg/Opus, align to the oldest known page boundary within the burst
+	// For Ogg/Opus, align to the oldest known page boundary within the valid buffer range
 	if strings.Contains(strings.ToLower(s.ContentType), "ogg") || strings.Contains(strings.ToLower(s.ContentType), "opus") {
+		validStart := s.Buffer.Head - s.Buffer.Size
+		if validStart < 0 { validStart = 0 }
+		
+		if start < validStart { start = validStart }
+
 		bestAlign := s.LastPageOffset
+		found := false
 		for _, po := range s.PageOffsets {
-			if po >= start && po < bestAlign {
+			// Find the smallest PO that is >= start AND is still valid
+			if po >= start && po >= validStart && po < bestAlign {
 				bestAlign = po
+				found = true
 			}
 		}
-		if bestAlign > 0 {
+		if found {
+			start = bestAlign
+		} else if bestAlign >= validStart {
 			start = bestAlign
+		} else {
+			start = s.Buffer.Head // Fallback to now if nothing valid found
 		}
 	}
 

server/server.go

@@ -913,14 +913,20 @@ func (s *Server) serveStreamData(w http.ResponseWriter, r *http.Request, stream
 	defer stream.Unsubscribe(id)
 
 	if stream.OggHead != nil {
-		// Always send stored headers for Ogg/Opus
+		// If we are starting from the very beginning of the stream (or burst includes start)
+		// we don't send OggHead because it's already in the buffer at OggHeaderOffset.
+		// BUT for simplicity and robustness, we ALWAYS send OggHead first and then 
+		// ensure our offset is correctly aligned AFTER the headers in the buffer.
 		if _, err := w.Write(stream.OggHead); err != nil {
 			return false
 		}
-		// If the burst offset is BEFORE the header end, skip the duplicate headers in the buffer
+		
+		// If our starting offset is before where the actual audio data starts, 
+		// skip the header part of the buffer to avoid sending them twice.
 		if offset < stream.OggHeaderOffset {
 			offset = stream.OggHeaderOffset
 		}
+		logrus.Debugf("Ogg Listener %s: Sending stored headers, then starting burst at %d (HeaderEnd: %d)", id, offset, stream.OggHeaderOffset)
 	}
 
 	buf := make([]byte, 16384)