navidrome/core/artwork/reader_resized.go

137 lines
3.3 KiB
Go

package artwork
import (
"bufio"
"bytes"
"context"
"fmt"
"image"
"image/jpeg"
"image/png"
"io"
"net/http"
"time"
"github.com/disintegration/imaging"
"github.com/navidrome/navidrome/conf"
"github.com/navidrome/navidrome/log"
"github.com/navidrome/navidrome/model"
)
type resizedArtworkReader struct {
artID model.ArtworkID
cacheKey string
lastUpdate time.Time
size int
a *artwork
}
func resizedFromOriginal(ctx context.Context, a *artwork, artID model.ArtworkID, size int) (*resizedArtworkReader, error) {
r := &resizedArtworkReader{a: a}
r.artID = artID
r.size = size
// Get lastUpdated and cacheKey from original artwork
original, err := a.getArtworkReader(ctx, artID, 0)
if err != nil {
return nil, err
}
r.cacheKey = original.Key()
r.lastUpdate = original.LastUpdated()
return r, nil
}
func (a *resizedArtworkReader) Key() string {
return fmt.Sprintf(
"%s.%d.%d",
a.cacheKey,
a.size,
conf.Server.CoverJpegQuality,
)
}
func (a *resizedArtworkReader) LastUpdated() time.Time {
return a.lastUpdate
}
func (a *resizedArtworkReader) Reader(ctx context.Context) (io.ReadCloser, string, error) {
// Get artwork in original size, possibly from cache
orig, _, err := a.a.Get(ctx, a.artID, 0)
if err != nil {
return nil, "", err
}
// Keep a copy of the original data. In case we can't resize it, send it as is
buf := new(bytes.Buffer)
r := io.TeeReader(orig, buf)
defer orig.Close()
resized, origSize, err := resizeImage(r, a.size)
if resized == nil {
log.Trace(ctx, "Image smaller than requested size", "artID", a.artID, "original", origSize, "resized", a.size)
} else {
log.Trace(ctx, "Resizing artwork", "artID", a.artID, "original", origSize, "resized", a.size)
}
if err != nil {
log.Warn(ctx, "Could not resize image. Will return image as is", "artID", a.artID, "size", a.size, err)
}
if err != nil || resized == nil {
// Force finish reading any remaining data
_, _ = io.Copy(io.Discard, r)
return io.NopCloser(buf), "", nil //nolint:nilerr
}
return io.NopCloser(resized), fmt.Sprintf("%s@%d", a.artID, a.size), nil
}
func asImageReader(r io.Reader) (io.Reader, string, error) {
br := bufio.NewReader(r)
buf, err := br.Peek(512)
if err == io.EOF && len(buf) > 0 {
// Check if there are enough bytes to detect type
typ := http.DetectContentType(buf)
if typ != "" {
return br, typ, nil
}
}
if err != nil {
return nil, "", err
}
return br, http.DetectContentType(buf), nil
}
func resizeImage(reader io.Reader, size int) (io.Reader, int, error) {
r, format, err := asImageReader(reader)
if err != nil {
return nil, 0, err
}
img, _, err := image.Decode(r)
if err != nil {
return nil, 0, err
}
// Don't upscale the image
bounds := img.Bounds()
originalSize := max(bounds.Max.X, bounds.Max.Y)
if originalSize <= size {
return nil, originalSize, nil
}
var m *image.NRGBA
// Preserve the aspect ratio of the image.
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)
buf.Reset()
if format == "image/png" {
err = png.Encode(buf, m)
} else {
err = jpeg.Encode(buf, m, &jpeg.Options{Quality: conf.Server.CoverJpegQuality})
}
return buf, originalSize, err
}