fix(converters): panic-safe stopping conversion

pkg/media/batch_converter.go

@@ -123,43 +123,44 @@ func (bc *BatchConverter) convertOne(task ConverterTask, progress chan BatchProg
 	singleConverter := NewConverter(bc.infoGetter)
 	_progress, _finished, _failed := singleConverter.Convert(task)
 
-	go func() {
-		for {
-			select {
-			case <-bc.stopConversion:
-				singleConverter.StopConversion()
-				return
-			}
-		}
-	}()
-
 	for {
 		select {
+		case <-bc.stopConversion:
+			singleConverter.StopConversion()
+
 		case <-singleConverter.ConversionStarted:
 			bc.TaskConversionStarted <- task
+
 		case metadata := <-singleConverter.MetadataReceived:
 			bc.MetadataReceived <- MetadataReceivedBatchMessage{
 				Metadata: metadata,
 				Task:     task,
 			}
+
 		case videoCodec := <-singleConverter.InputVideoCodecDetected:
 			bc.InputVideoCodecDetected <- InputVideoCodecDetectedBatchMessage{
 				Codec: videoCodec,
 				Task:  task,
 			}
+
 		case <-singleConverter.ConversionStopping:
 			bc.ConversionStopping <- task
+
 		case <-singleConverter.ConversionStopped:
 			bc.ConversionStopped <- task
+
 		case progressMessage := <-_progress:
 			progress <- BatchProgressMessage{
 				Progress: progressMessage,
 				Task:     task,
 			}
+
 		case errorMessage := <-_failed:
 			return errorMessage
+
 		case <-_finished:
 			return nil
+
 		}
 	}
 }

pkg/media/converter.go

@@ -84,19 +84,6 @@ func (c *Converter) Convert(task ConverterTask) (
 			return
 		}
 
-		go func() {
-			for {
-				select {
-				case <-c.stopConversion:
-					c.ConversionStopping <- true
-					trans.Stop()
-					c.ConversionStopped <- true
-					finished <- true
-					return
-				}
-			}
-		}()
-
 		metadata, err := c.infoGetter.GetMediaInfo(task.InFile)
 
 		if err != nil {
@@ -149,6 +136,13 @@ func (c *Converter) Convert(task ConverterTask) (
 
 		for {
 			select {
+			case <-c.stopConversion:
+				c.ConversionStopping <- true
+				trans.Stop()
+				c.ConversionStopped <- true
+				finished <- true
+				return
+
 			case progressMessage := <-_progress:
 				if progressMessage.FramesProcessed != "" {
 					progress <- ConvertProgress{
@@ -161,6 +155,7 @@ func (c *Converter) Convert(task ConverterTask) (
 						File:            task.InFile,
 					}
 				}
+
 			case err := <-done:
 				if err != nil {
 					failed <- err