Resize if requested

core/artwork.go

@@ -4,12 +4,19 @@ import (
 	"bytes"
 	"context"
 	"errors"
+	"fmt"
+	"image"
 	_ "image/gif"
-	_ "image/png"
+	"image/jpeg"
+	"image/png"
 	"io"
 	"os"
+	"path/filepath"
+	"strings"
 
 	"github.com/dhowden/tag"
+	"github.com/disintegration/imaging"
+	"github.com/navidrome/navidrome/conf"
 	"github.com/navidrome/navidrome/consts"
 	"github.com/navidrome/navidrome/log"
 	"github.com/navidrome/navidrome/model"
@@ -34,11 +41,17 @@ func (a *artwork) Get(ctx context.Context, id string, size int) (io.ReadCloser,
 	return r, err
 }
 
-func (a *artwork) get(ctx context.Context, id string, size int) (io.ReadCloser, string, error) {
+func (a *artwork) get(ctx context.Context, id string, size int) (reader io.ReadCloser, path string, err error) {
 	artId, err := model.ParseArtworkID(id)
 	if err != nil {
 		return nil, "", errors.New("invalid ID")
 	}
+
+	// If requested a resized
+	if size > 0 {
+		return a.resizedFromOriginal(ctx, id, size)
+	}
+
 	id = artId.ID
 	al, err := a.ds.Album(ctx).Get(id)
 	if errors.Is(err, model.ErrNotFound) {
@@ -48,13 +61,34 @@ func (a *artwork) get(ctx context.Context, id string, size int) (io.ReadCloser,
 	if err != nil {
 		return nil, "", err
 	}
+
 	r, path := extractImage(ctx, artId,
+		fromExternalFile(al.ImageFiles, "cover.png", "cover.jpg", "cover.jpeg", "cover.webp"),
+		fromExternalFile(al.ImageFiles, "folder.png", "folder.jpg", "folder.jpeg", "folder.webp"),
+		fromExternalFile(al.ImageFiles, "album.png", "album.jpg", "album.jpeg", "album.webp"),
+		fromExternalFile(al.ImageFiles, "albumart.png", "albumart.jpg", "albumart.jpeg", "albumart.webp"),
+		fromExternalFile(al.ImageFiles, "front.png", "front.jpg", "front.jpeg", "front.webp"),
 		fromTag(al.EmbedArtPath),
 		fromPlaceholder(),
 	)
 	return r, path, nil
 }
 
+func (a *artwork) resizedFromOriginal(ctx context.Context, id string, size int) (io.ReadCloser, string, error) {
+	r, path, err := a.get(ctx, id, 0)
+	if err != nil || r == nil {
+		return nil, "", err
+	}
+	defer r.Close()
+	usePng := strings.ToLower(filepath.Ext(path)) == ".png"
+	r, err = resizeImage(r, size, usePng)
+	if err != nil {
+		r, path := fromPlaceholder()()
+		return r, path, err
+	}
+	return r, fmt.Sprintf("%s@%d", path, size), nil
+}
+
 func extractImage(ctx context.Context, artId model.ArtworkID, extractFuncs ...func() (io.ReadCloser, string)) (io.ReadCloser, string) {
 	for _, f := range extractFuncs {
 		r, path := f()
@@ -67,8 +101,33 @@ func extractImage(ctx context.Context, artId model.ArtworkID, extractFuncs ...fu
 	return nil, ""
 }
 
+// This seems unoptimized, but we need to make sure the priority order of validNames
+// is preserved (i.e. png is better than jpg)
+func fromExternalFile(files string, validNames ...string) func() (io.ReadCloser, string) {
+	return func() (io.ReadCloser, string) {
+		fileList := filepath.SplitList(files)
+		for _, validName := range validNames {
+			for _, file := range fileList {
+				_, name := filepath.Split(file)
+				if !strings.EqualFold(validName, name) {
+					continue
+				}
+				f, err := os.Open(file)
+				if err != nil {
+					continue
+				}
+				return f, file
+			}
+		}
+		return nil, ""
+	}
+}
+
 func fromTag(path string) func() (io.ReadCloser, string) {
 	return func() (io.ReadCloser, string) {
+		if path == "" {
+			return nil, ""
+		}
 		f, err := os.Open(path)
 		if err != nil {
 			return nil, ""
@@ -94,3 +153,27 @@ func fromPlaceholder() func() (io.ReadCloser, string) {
 		return r, consts.PlaceholderAlbumArt
 	}
 }
+
+func resizeImage(reader io.Reader, size int, usePng bool) (io.ReadCloser, error) {
+	img, _, err := image.Decode(reader)
+	if err != nil {
+		return nil, err
+	}
+
+	// Preserve the aspect ratio of the image.
+	var m *image.NRGBA
+	bounds := img.Bounds()
+	if bounds.Max.X > bounds.Max.Y {
+		m = imaging.Resize(img, size, 0, imaging.Lanczos)
+	} else {
+		m = imaging.Resize(img, 0, size, imaging.Lanczos)
+	}
+
+	buf := new(bytes.Buffer)
+	if usePng {
+		err = png.Encode(buf, m)
+	} else {
+		err = jpeg.Encode(buf, m, &jpeg.Options{Quality: conf.Server.CoverJpegQuality})
+	}
+	return io.NopCloser(buf), err
+}