error handling for zero bytes

.gitignore

@@ -1,4 +1,8 @@
 *.gif
 *.jpeg
 *.png
+*.mp4
+./imgs/*
+imgs/
+glitch_img
 .DS_Store

README.md

@@ -24,7 +24,7 @@ go build
 ### Example
 
 ```bash
-./glitch*img img.jpeg 100 30 2
+./glitch_img img.jpeg 100 30 2
 ```
 
 Outputs 100 images into a destination folder _output_ with 30 random bytes of data, running through the file twice

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

@@ -1,22 +1,22 @@
 package main
 
 import (
+	"fmt"
 	"math/rand/v2"
 	"os"
 	"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
@@ -39,6 +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
@@ -51,10 +55,54 @@ 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")
 
-		// fmt.Printf("Successfully wrote %d bytes of shit at offset %d in file %s\n", shitSize, offset, outputFilePath)
 	}
 	return nil
 }
+
+func copyImage(inputFile string, outputFile string) error {
+	// Prepend the "output" directory to the output file
+	outputFilePath := filepath.Join("output", outputFile)
+
+	// Open the source file for reading
+	source, err := os.Open(inputFile)
+	check(err, "failed to open source file: %w")
+	defer source.Close()
+
+	// Create a new file for writing the copy
+	destination, err := os.Create(outputFilePath)
+	check(err, "failed to create output file: %w")
+	defer destination.Close()
+
+	// Copy the contents of the source file to the destination
+	_, err = destination.ReadFrom(source)
+	check(err, "failed to copy file contents: %w")
+
+	// no errors
+	return nil
+}
+
+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.%s", i, fileExt)
+
+		if rand.Int32N(100) < chanceToRandom {
+			// Glitched image
+			err := glitchImage(inputFile, outputFileName, shitSize, iterations)
+			if err != nil {
+				return fmt.Errorf("Cannot glitch image")
+			}
+		} else {
+			// Normal image
+			err := copyImage(inputFile, outputFileName)
+			if err != nil {
+				return fmt.Errorf("Cannot glitch image")
+			}
+		}
+	}
+	// no errors
+	return nil
+}

main.go

@@ -3,18 +3,28 @@ package main
 import (
 	"fmt"
 	"os"
-	"os/exec"
 	"path/filepath"
 	"strconv"
 )
 
+// TODO:
+// - Flags instead of os.Args
+// - Interactive UI
+// - Check compatability with other image types (PNG etc)
+// - better ffmpeg bindings (go package?)
+// - Update README
+
+const MAX_SIZE = 1000000
+
 func main() {
-	if len(os.Args) < 5 {
-		fmt.Println("Usage: go run main.go <source-file> <number-of-copies> <shit-size> <iterations>")
+	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.")
@@ -25,27 +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),
-		)
+	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
+	}
 
-		err := glitchImage(sourceFile, outputFile, shitSize, iterations)
+	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 {
-			fmt.Printf("Error glitching file %d: %v\n", i, err)
+		return
 	}
-	}
-
-	fmt.Println("GENREATING GIF YEAHH ")
-	// now run ffmpeg to make a gif!
-	cmd := exec.Command("ffmpeg", "-y", "-framerate 60", "-i", "./output/img_glitched_%d.jpeg output.gif")
-	err = cmd.Run()
-	check(err, "cannot run ffmpeg command!")
-	//
+	ffmpegGenerateMP4(fileExt)
 }

util.go

@@ -2,6 +2,7 @@ package main
 
 import (
 	"fmt"
+	"os"
 	"path/filepath"
 )
 
@@ -11,7 +12,35 @@ func check(e error, s string) {
 	}
 }
 
+func dots(count int) string {
+	dotStr := ""
+	for i := 0; i < count; i++ {
+		dotStr += "."
+	}
+	return dotStr
+}
+
 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: 
+  `)
+}