Fix bailout after muxing when an input stream has closed.

internal/media/muxer.go

@@ -103,9 +103,19 @@ func Mux(muxer string, readers ...io.ReadCloser) (retval io.Reader) {
 				Chan: reflect.ValueOf(c.Ctx.GetNewPackets()),
 			}
 		}
+		var closedStreamIndex = 0
+		defer func() {
+			for i, r := range readers {
+				if i == closedStreamIndex {
+					continue
+				}
+				r.Close()
+			}
+		}()
 		for err == nil {
 			streamIndex, packetVal, ok := reflect.Select(cases)
 			if !ok {
+				closedStreamIndex = streamIndex
 				break // some stream has been closed, just close them all
 			}
 			packet := packetVal.Interface().(*gmf.Packet)
@@ -113,10 +123,6 @@ func Mux(muxer string, readers ...io.ReadCloser) (retval io.Reader) {
 			err = output.Ctx.WritePacket(packet)
 			packet.Release()
 		}
-		log.Println("Bailing out")
-		for _, r := range readers {
-			r.Close()
-		}
 		output.Ctx.WriteTrailer()
 	}()