From 64fb152c3699f189f51fd9c2171c846c5da67f9b Mon Sep 17 00:00:00 2001
From: Milan Nikolic <gen2brain@gmail.com>
Date: Sat, 4 Mar 2023 10:27:01 +0100
Subject: [PATCH] Cover format, issue #18

---
 README.md             |  4 +++-
 cbconvert.go          | 30 ++++++++++++++----------------
 cmd/cbconvert/main.go |  1 +
 3 files changed, 18 insertions(+), 17 deletions(-)

diff --git a/README.md b/README.md
index 8699f18..68bce2b 100644
--- a/README.md
+++ b/README.md
@@ -113,8 +113,10 @@ This is what it looks like in the PCManFM file manager:
             Image height (default "0")
         --fit
             Best fit for required width and height (default "false")
+        --format
+            Image format, valid values are jpeg, png, tiff, bmp, webp, avif (default "jpeg")
         --quality
-            JPEG image quality (default "75")
+            Image quality (default "75")
         --filter
             0=NearestNeighbor, 1=Box, 2=Linear, 3=MitchellNetravali, 4=CatmullRom, 6=Gaussian, 7=Lanczos (default "2")
         --outdir
diff --git a/cbconvert.go b/cbconvert.go
index e164b9c..aab279c 100644
--- a/cbconvert.go
+++ b/cbconvert.go
@@ -166,12 +166,11 @@ func (c *Convertor) convertImage(ctx context.Context, img image.Image, index int
 		c.OnProgress()
 	}
 
-	var ext = c.Opts.Format
 	var fileName string
 	if pathName != "" {
-		fileName = filepath.Join(c.Workdir, fmt.Sprintf("%s.%s", c.baseNoExt(pathName), ext))
+		fileName = filepath.Join(c.Workdir, fmt.Sprintf("%s.%s", c.baseNoExt(pathName), c.Opts.Format))
 	} else {
-		fileName = filepath.Join(c.Workdir, fmt.Sprintf("%03d.%s", index, ext))
+		fileName = filepath.Join(c.Workdir, fmt.Sprintf("%03d.%s", index, c.Opts.Format))
 	}
 
 	img = c.transformImage(img)
@@ -1136,20 +1135,19 @@ func (c *Convertor) ExtractCover(fileName string, fileInfo os.FileInfo) error {
 		}
 	}
 
-	fname := filepath.Join(c.Opts.Outdir, fmt.Sprintf("%s.jpg", c.baseNoExt(fileName)))
-	file, err := os.Create(fname)
-	if err != nil {
-		return fmt.Errorf("extractCover: %w", err)
-	}
+	fName := filepath.Join(c.Opts.Outdir, fmt.Sprintf("%s.%s", c.baseNoExt(fileName), c.Opts.Format))
 
-	err = jpeg.Encode(file, cover, &jpeg.Options{Quality: c.Opts.Quality})
-	if err != nil {
-		return fmt.Errorf("extractCover: %w", err)
-	}
-
-	err = file.Close()
-	if err != nil {
-		return fmt.Errorf("extractCover: %w", err)
+	switch c.Opts.Format {
+	case "jpeg", "png", "tiff", "webp", "avif":
+		err = c.encodeImage(cover, fName)
+		if err != nil {
+			return err
+		}
+	case "bmp":
+		err = c.encodeIM(cover, fName)
+		if err != nil {
+			return err
+		}
 	}
 
 	return nil
diff --git a/cmd/cbconvert/main.go b/cmd/cbconvert/main.go
index fd75602..8fc6ae9 100644
--- a/cmd/cbconvert/main.go
+++ b/cmd/cbconvert/main.go
@@ -152,6 +152,7 @@ func parseFlags() (cbconvert.Options, []string) {
 	cover.IntVar(&opts.Width, "width", 0, "Image width")
 	cover.IntVar(&opts.Height, "height", 0, "Image height")
 	cover.BoolVar(&opts.Fit, "fit", false, "Best fit for required width and height")
+	cover.StringVar(&opts.Format, "format", "jpeg", "Image format, valid values are jpeg, png, tiff, bmp, webp, avif")
 	cover.IntVar(&opts.Quality, "quality", 75, "Image quality")
 	cover.IntVar(&opts.Filter, "filter", 2, "0=NearestNeighbor, 1=Box, 2=Linear, 3=MitchellNetravali, 4=CatmullRom, 6=Gaussian, 7=Lanczos")
 	cover.StringVar(&opts.Outdir, "outdir", ".", "Output directory")