Merged in pipeline-error-handling (pull request #434)

revid/pipeline.go: improved handling of undefined pipeline permutations

Approved-by: Trek Hopton

revid/pipeline.go

@@ -69,7 +69,7 @@ func (r *Revid) reset(c config.Config) error {
 	r.cfg.Logger.Log(logger.Debug, "setting config")
 	err := r.setConfig(c)
 	if err != nil {
-		return err
+		return fmt.Errorf("could not set config: %w",err)
 	}
 	r.cfg.Logger.Log(logger.Info, "config set")
 
@@ -85,7 +85,7 @@ func (r *Revid) reset(c config.Config) error {
 				switch r.cfg.InputCodec {
 				case codecutil.H265:
 					if r.cfg.Input != config.InputRTSP {
-						panic("H265 codec valid only for InputRTSP")
+						return nil, errors.New("h.265 codec valid only for InputRTSP")
 					}
 					st = mts.EncodeH265
 				case codecutil.H264:
@@ -94,8 +94,10 @@ func (r *Revid) reset(c config.Config) error {
 					st = mts.EncodeMJPEG
 					encOptions = append(encOptions, mts.TimeBasedPSI(time.Duration(r.cfg.PSITime)*time.Second))
 					r.cfg.CBR = true
+				case codecutil.PCM, codecutil.ADPCM:
+					return nil, errors.New(fmt.Sprintf("invalid input codec: %v for input: %v",r.cfg.InputCodec,r.cfg.Input))
 				default:
-					panic("unknown input codec for Raspivid, File, V4l or RTSP input")
+					panic("unknown input codec")
 				}
 			case config.InputAudio:
 				st = mts.EncodeAudio
@@ -115,7 +117,7 @@ func (r *Revid) reset(c config.Config) error {
 	r.cfg.Logger.Log(logger.Info, "finished setting pipeline")
 
 	if err != nil {
-		return err
+		return fmt.Errorf("could not set up pipeline: %w",err)
 	}
 
 	return nil
@@ -246,46 +248,47 @@ func (r *Revid) setupPipeline(mtsEnc func(dst io.WriteCloser, rate float64) (io.
 				r.cfg.Logger.Log(logger.Debug, "using go difference filter")
 				r.filters[i] = filter.NewBasic(dst, r.cfg)
 			default:
-				panic("Undefined Filter")
+				panic("unknown filter")
 			}
 			dst = r.filters[i]
 		}
 		r.cfg.Logger.Log(logger.Info, "filters set up")
 	}
 
+	var err error
 	switch r.cfg.Input {
 	case config.InputRaspivid:
 		r.cfg.Logger.Log(logger.Debug, "using raspivid input")
 		r.input = raspivid.New(r.cfg.Logger)
-		r.setLexer(r.cfg.InputCodec, false)
+		err = r.setLexer(r.cfg.InputCodec, false)
 
 	case config.InputV4L:
 		r.cfg.Logger.Log(logger.Debug, "using V4L input")
 		r.input = webcam.New(r.cfg.Logger)
-		r.setLexer(r.cfg.InputCodec, false)
+		err = r.setLexer(r.cfg.InputCodec, false)
 
 	case config.InputFile:
 		r.cfg.Logger.Log(logger.Debug, "using file input")
 		r.input = file.New()
-		r.setLexer(r.cfg.InputCodec, false)
+		err = r.setLexer(r.cfg.InputCodec, false)
 
 	case config.InputRTSP:
 		r.cfg.Logger.Log(logger.Debug, "using RTSP input")
 		r.input = geovision.New(r.cfg.Logger)
-		r.setLexer(r.cfg.InputCodec, true)
+		err = r.setLexer(r.cfg.InputCodec, true)
 
 	case config.InputAudio:
 		r.cfg.Logger.Log(logger.Debug, "using audio input")
-		err := r.setupAudio()
-		if err != nil {
-			return err
-		}
+		err = r.setupAudio()
+	}
+	if err != nil {
+		return fmt.Errorf("could not set lexer: %w",err)
 	}
 
 	// Configure the input device. We know that defaults are set, so no need to
 	// return error, but we should log.
 	r.cfg.Logger.Log(logger.Debug, "configuring input device")
-	err := r.input.Set(r.cfg)
+	err = r.input.Set(r.cfg)
 	if err != nil {
 		r.cfg.Logger.Log(logger.Warning, "errors from configuring input device", "errors", err)
 	}
@@ -296,7 +299,7 @@ func (r *Revid) setupPipeline(mtsEnc func(dst io.WriteCloser, rate float64) (io.
 
 // setLexer sets the revid input lexer based on input codec and whether input
 // is RTSP or not, in which case an RTP/<codec> extractor is used.
-func (r *Revid) setLexer(c uint8, isRTSP bool) {
+func (r *Revid) setLexer(c uint8, isRTSP bool) error {
 	switch c {
 	case codecutil.H264:
 		r.cfg.Logger.Log(logger.Debug, "using H.264 codec")
@@ -308,7 +311,7 @@ func (r *Revid) setLexer(c uint8, isRTSP bool) {
 		r.cfg.Logger.Log(logger.Debug, "using H.265 codec")
 		r.lexTo = h265.NewExtractor(false).Extract
 		if !isRTSP {
-			panic("byte stream H.265 lexing not implemented")
+			return errors.New("byte stream h.265 lexing not implemented")
 		}
 	case codecutil.MJPEG:
 		r.cfg.Logger.Log(logger.Debug, "using MJPEG codec")
@@ -316,9 +319,12 @@ func (r *Revid) setLexer(c uint8, isRTSP bool) {
 		if isRTSP {
 			r.lexTo = mjpeg.NewExtractor().Extract
 		}
+	case codecutil.PCM, codecutil.ADPCM:
+		return errors.New("invalid codec for this selected input")
 	default:
 		panic("unrecognised codec")
 	}
+	return nil
 }
 
 // processFrom is run as a routine to read from a input data source, lex and