revid: clean up input handling

revid/revid.go

@@ -36,7 +36,6 @@ import (
 	"io"
 	"os"
 	"os/exec"
-	"path/filepath"
 	"strconv"
 	"time"
 
@@ -88,7 +87,6 @@ type Revid struct {
 	ringBuffer  *ring.Buffer
 	config      Config
 	isRunning   bool
-	inputFile   *os.File
 	generator   generator.Generator
 	parser      parser.Parser
 	cmd         *exec.Cmd
@@ -172,7 +170,7 @@ func (r *Revid) reset(config Config) error {
 
 	switch r.config.Input {
 	case Raspivid:
-		r.setupInput = r.setupInputForRaspivid
+		r.setupInput = r.startRaspivid
 	case File:
 		r.setupInput = r.setupInputForFile
 	}
@@ -432,13 +430,14 @@ func (r *Revid) outputClips() {
 	}
 }
 
-// setupInputForRaspivid sets up things for input from raspivid i.e. starts
+// startRaspivid sets up things for input from raspivid i.e. starts
 // a raspivid process and pipes it's data output.
-func (r *Revid) setupInputForRaspivid() error {
+func (r *Revid) startRaspivid() error {
 	r.Log(Info, "Starting raspivid!")
 	switch r.config.InputCodec {
 	case H264:
-		arguments := []string{"-cd", "H264",
+		args := []string{
+			"-cd", "H264",
 			"-o", "-",
 			"-n",
 			"-t", r.config.Timeout,
@@ -449,33 +448,18 @@ func (r *Revid) setupInputForRaspivid() error {
 			"-ih",
 			"-g", r.config.IntraRefreshPeriod,
 		}
-
 		if r.config.QuantizationMode == QuantizationOn {
-			arguments = append(arguments, "-qp")
-			arguments = append(arguments, r.config.Quantization)
+			args = append(args, "-qp", r.config.Quantization)
 		}
-
 		if r.config.HorizontalFlip == Yes {
-			arguments = append(arguments, "-hf")
+			args = append(args, "-hf")
+		}
+		if r.config.VerticalFlip == Yes {
+			args = append(args, "-vf")
 		}
 
-		if r.config.VerticalFlip == Yes {
-			arguments = append(arguments, "-vf")
-		}
-		name := "raspivid"
-		r.cmd = &exec.Cmd{
-			Path: name,
-			Args: append([]string{name}, arguments...),
-		}
-		r.Log(Info, fmt.Sprintf("Startin raspivid with args: %v", r.cmd.Args))
-		if filepath.Base(name) == name {
-			if lp, err := exec.LookPath(name); err != nil {
-				r.Log(Error, err.Error())
-				return err
-			} else {
-				r.cmd.Path = lp
-			}
-		}
+		r.Log(Info, fmt.Sprintf("Starting raspivid with args: %v", args))
+		r.cmd = exec.Command("raspivid", args...)
 
 	case Mjpeg:
 		r.cmd = exec.Command("raspivid",
@@ -486,31 +470,29 @@ func (r *Revid) setupInputForRaspivid() error {
 			"-fps", r.config.FrameRate,
 		)
 	}
-	stdout, _ := r.cmd.StdoutPipe()
-	go r.cmd.Run()
+	stdout, err := r.cmd.StdoutPipe()
+	if err != nil {
+		return err
+	}
+	err = r.cmd.Start()
+	if err != nil {
+		return err
+	}
 	r.inputReader = bufio.NewReader(stdout)
 	go r.readCamera()
 	return nil
 }
 
-// setupInputForFile sets things up for getting input from a file
-func (r *Revid) setupInputForFile() error {
-	fps, _ := strconv.Atoi(r.config.FrameRate)
-	r.parser.SetDelay(uint(float64(1000) / float64(fps)))
-	r.readFile()
-	return nil
-}
-
 // readCamera reads data from the defined camera while the Revid is running.
 // TODO: use ringbuffer here instead of allocating mem every time!
 func (r *Revid) readCamera() {
 	r.Log(Info, "Reading camera data!")
 	for r.isRunning {
-		data := make([]byte, 1)
-		_, err := io.ReadFull(r.inputReader, data)
+		var data [1]byte
+		_, err := io.ReadFull(r.inputReader, data[:])
 		switch {
 		// We know this means we're getting nothing from the cam
-		case (err != nil && err.Error() == "EOF" && r.isRunning) || (err != nil && r.isRunning):
+		case err != nil && r.isRunning:
 			r.Log(Error, "No data from camera!")
 			time.Sleep(cameraRetryPeriod)
 		default:
@@ -520,31 +502,39 @@ func (r *Revid) readCamera() {
 	r.Log(Info, "Not trying to read from camera anymore!")
 }
 
+// setupInputForFile sets things up for getting input from a file
+func (r *Revid) setupInputForFile() error {
+	fps, err := strconv.Atoi(r.config.FrameRate)
+	if err != nil {
+		return err
+	}
+	r.parser.SetDelay(uint(float64(1000) / float64(fps)))
+	return r.readFile()
+}
+
 // readFile reads data from the defined file while the Revid is running.
 func (r *Revid) readFile() error {
-	var err error
-	r.inputFile, err = os.Open(r.config.InputFileName)
+	f, err := os.Open(r.config.InputFileName)
 	if err != nil {
 		r.Log(Error, err.Error())
 		r.Stop()
 		return err
 	}
-	stats, err := r.inputFile.Stat()
-	if err != nil {
-		r.Log(Error, "Could not get input file stats!")
-		r.Stop()
-		return err
+	defer f.Close()
+	var buf [1 << 12]byte
+	for {
+		n, err := f.Read(buf[:])
+		for _, b := range buf[:n] {
+			r.parser.InputChan() <- b
+		}
+		if err != nil {
+			if err == io.EOF {
+				break
+			}
+			r.Log(Error, err.Error())
+			r.Stop()
+			return err
+		}
 	}
-	data := make([]byte, stats.Size())
-	_, err = r.inputFile.Read(data)
-	if err != nil {
-		r.Log(Error, err.Error())
-		r.Stop()
-		return err
-	}
-	for i := range data {
-		r.parser.InputChan() <- data[i]
-	}
-	r.inputFile.Close()
 	return nil
 }