error handling for zero bytes

.gitignore

@@ -2,4 +2,7 @@
 *.jpeg
 *.png
 *.mp4
+./imgs/*
+imgs/
+glitch_img
 .DS_Store

ffmpeg.go

@@ -0,0 +1,50 @@
+package main
+
+import (
+	"fmt"
+	"os/exec"
+	"time"
+)
+
+func ffmpegGenerateMP4(fileExt string) {
+	inputPattern := "./output/img_glitched_%d." + fileExt
+	outputVideo := "output.mp4"
+
+	cmd := exec.Command(
+		"ffmpeg",
+		"-y",
+		"-framerate", "30",
+		"-i", inputPattern,
+		"-vf", "scale=trunc(iw/2)*2:trunc(ih/2)*2,setpts=PTS*2.0", // Scale and slow down playback
+		"-vcodec", "libx264", // Use H.264 codec
+		"-pix_fmt", "yuv420p",
+		"-crf", "23", // Compression level: lower is higher quality (range: 18-28)
+		"-preset", "fast",
+		outputVideo,
+	)
+
+	done := make(chan bool)
+
+	go func() {
+		err := cmd.Run()
+		check(err, "cannot run ffmpeg command!")
+		done <- true
+	}()
+
+	go func() {
+		msg := "Generating MP4"
+		c := 0
+		for {
+			select {
+			case <-done:
+				return
+			default:
+				fmt.Printf("\r%s%s", msg, dots(c))
+				c = (c + 1)
+				time.Sleep(500 * time.Millisecond)
+			}
+		}
+	}()
+	<-done
+	fmt.Println("\nGIF successfully created in ./output.mp4!")
+}

glitch.go

@@ -7,17 +7,16 @@ import (
 	"path/filepath"
 )
 
-func makeOutputDir() {
-	// Default to just "output"
-	err := os.Mkdir("output", 0755)
-	check(err, "cannot make directory")
+func fillSliceWithASCII(slice []byte) {
+	const asciiMin = 16
+	const asciiMax = 150
+
+	for i := range slice {
+		slice[i] = byte(rand.Int32N(asciiMax-asciiMin+1) + asciiMin)
+	}
 }
 
 func glitchImage(inputFile string, outputFile string, shitSize int64, iterations int64) error {
-	// Ensure the output directory exists
-	makeOutputDir()
-
-	// Prepend the "output" directory to the output file
 	outputFilePath := filepath.Join("output", outputFile)
 
 	// Open the source file for reading
@@ -40,6 +39,10 @@ func glitchImage(inputFile string, outputFile string, shitSize int64, iterations
 
 	// Get the size of the destination file
 	fileSize := fileInfo.Size()
+	if fileSize == 0 {
+		fmt.Println("Cannot glitch file with size of zero bytes!")
+		return fmt.Errorf("input file is zero bytes")
+	}
 
 	// Generate a random offset within the file
 	var i int64
@@ -52,6 +55,7 @@ func glitchImage(inputFile string, outputFile string, shitSize int64, iterations
 
 		// Generate random data and write it in
 		shit := make([]byte, shitSize)
+		fillSliceWithASCII(shit)
 		_, err = destination.Write(shit)
 		check(err, "failed to write shit data: %w")
 
@@ -60,9 +64,6 @@ func glitchImage(inputFile string, outputFile string, shitSize int64, iterations
 }
 
 func copyImage(inputFile string, outputFile string) error {
-	// Ensure the output directory exists
-	makeOutputDir()
-
 	// Prepend the "output" directory to the output file
 	outputFilePath := filepath.Join("output", outputFile)
 
@@ -80,22 +81,28 @@ func copyImage(inputFile string, outputFile string) error {
 	_, err = destination.ReadFrom(source)
 	check(err, "failed to copy file contents: %w")
 
+	// no errors
 	return nil
 }
 
-func generateGlitchedSequence(inputFile string, totalImages int, shitSize int64, iterations int64) {
+func generateGlitchedSequence(inputFile string, fileExt string, totalImages int, shitSize int64, iterations int64, chanceToRandom int32) error {
 	for i := 1; i <= totalImages; i++ {
-		outputFileName := fmt.Sprintf("img_glitched_%d.jpeg", i) // Generate unique filenames
+		outputFileName := fmt.Sprintf("img_glitched_%d.%s", i, fileExt)
 
-		// Randomly decide whether to glitch or copy the image
-		if rand.Int32N(2) == 0 {
+		if rand.Int32N(100) < chanceToRandom {
 			// Glitched image
 			err := glitchImage(inputFile, outputFileName, shitSize, iterations)
-			check(err, "failed to glitch image: %w")
+			if err != nil {
+				return fmt.Errorf("Cannot glitch image")
+			}
 		} else {
 			// Normal image
 			err := copyImage(inputFile, outputFileName)
-			check(err, "failed to copy normal image: %w")
+			if err != nil {
+				return fmt.Errorf("Cannot glitch image")
 			}
 		}
 	}
+	// no errors
+	return nil
+}

main.go

@@ -2,22 +2,29 @@ package main
 
 import (
 	"fmt"
-	"math/rand"
 	"os"
-	"os/exec"
+	"path/filepath"
 	"strconv"
-	"time"
 )
 
-func main() {
-	rand.Seed(time.Now().UnixNano())
+// TODO:
+// - Flags instead of os.Args
+// - Interactive UI
+// - Check compatability with other image types (PNG etc)
+// - better ffmpeg bindings (go package?)
+// - Update README
 
-	if len(os.Args) < 5 {
-		fmt.Println("Usage: go run main.go <source-file> <number-of-copies> <shit-size> <iterations>")
+const MAX_SIZE = 1000000
+
+func main() {
+	if len(os.Args) < 6 {
+		fmt.Println("Usage: ./glitch.go <source-file> <number-of-copies> <shit-size> <iterations> <chance-to-random % (0-100)>")
 		return
 	}
 
 	sourceFile := os.Args[1]
+	fileExt := filepath.Ext(sourceFile)
+
 	numCopies, err := strconv.Atoi(os.Args[2])
 	if err != nil || numCopies <= 0 {
 		fmt.Println("Invalid number of copies. Must be a positive integer.")
@@ -28,65 +35,32 @@ func main() {
 	if err != nil || shitSize <= 0 {
 		fmt.Println("Invalid shit size. Must be a positive integer.")
 		return
+	} else if shitSize > MAX_SIZE {
+		fmt.Printf("shitSize exceeds maximum size (%d)\n", MAX_SIZE)
+		return
 	}
 
 	iterations, err := strconv.ParseInt(os.Args[4], 10, 8)
+	check(err, "Cannot parse iterations. Must be a positive integer")
 
-	/*
-		for i := 1; i <= numCopies; i++ {
-			outputFile := fmt.Sprintf("%s_glitched_%d%s",
-				stripExtension(sourceFile),
-				i,
-				filepath.Ext(sourceFile),
-			)
-
-				err := glitchImage(sourceFile, outputFile, shitSize, iterations)
-				if err != nil {
-					fmt.Printf("Error glitching file %d: %v\n", i, err)
-				}
-		}
-	*/
-	generateGlitchedSequence(sourceFile, numCopies, shitSize, iterations)
-
-	inputPattern := "./output/img_glitched_%d.jpeg"
-	outputVideo := "output.mp4"
-
-	cmd := exec.Command(
-		"ffmpeg",
-		"-y",
-		"-framerate", "30",
-		"-i", inputPattern,
-		"-vf", "scale=trunc(iw/2)*2:trunc(ih/2)*2,setpts=PTS*2.0", // Scale and slow down playback
-		"-vcodec", "libx264", // Use H.264 codec
-		"-pix_fmt", "yuv420p",
-		"-crf", "23", // Compression level: lower is higher quality (range: 18-28)
-		"-preset", "fast",
-		outputVideo,
-	)
-
-	done := make(chan bool)
-
-	go func() {
-		err := cmd.Run()
-		check(err, "cannot run ffmpeg command!")
-		done <- true
-	}()
-
-	go func() {
-		msg := "Generating MP4"
-		c := 0
-		for {
-			select {
-			case <-done:
+	chanceToRandom, err := strconv.ParseInt(os.Args[5], 10, 32)
+	if err != nil || chanceToRandom < 0 {
+		fmt.Println("Invalid random chance value. Must be a positive integer (0-100).")
+		return
+	} else if chanceToRandom > 100 {
+		fmt.Println("Invalid random chance value. Must range between 0 to 100.")
 		return
-			default:
-				fmt.Printf("\r%s%s", msg, dots(c))
-				c = (c + 1)
-				time.Sleep(500 * time.Millisecond)
 	}
+
+	fmt.Fprintf(os.Stdout, "Generating:\n %d copies of %s\n %d random bytes of data\n %d interations(s)\n Chance to random %d%%\n File Extention: %s\n\n",
+		numCopies, sourceFile, shitSize, iterations, chanceToRandom, fileExt)
+
+	makeOutputDir()
+	defer clearOutputDir()
+
+	err = generateGlitchedSequence(sourceFile, fileExt, numCopies, shitSize, iterations, int32(chanceToRandom))
+	if err != nil {
+		return
 	}
-	}()
-	<-done
-	fmt.Println("\nGIF successfully created in ./output.mp4!")
-	//
+	ffmpegGenerateMP4(fileExt)
 }

util.go

@@ -2,6 +2,7 @@ package main
 
 import (
 	"fmt"
+	"os"
 	"path/filepath"
 )
 
@@ -23,3 +24,23 @@ func stripExtension(filename string) string {
 	ext := filepath.Ext(filename)
 	return filename[:len(filename)-len(ext)]
 }
+
+func makeOutputDir() {
+	// Default to just "output"
+	err := os.Mkdir("output", 0755)
+	check(err, "cannot make directory")
+	return
+}
+
+func clearOutputDir() {
+	err := os.RemoveAll("./output")
+	check(err, "cannot remove directory")
+	return
+}
+
+func printUsage() {
+	fmt.Println("Usage: go run main.go <source-file> <number-of-copies> <shit-size> <iterations>")
+	fmt.Println(`
+    source-file: 
+  `)
+}