126 lines
2.6 KiB
Go
126 lines
2.6 KiB
Go
package util
|
|
|
|
import (
|
|
"bytes"
|
|
"fmt"
|
|
"image"
|
|
"image/jpeg"
|
|
"io"
|
|
"os"
|
|
|
|
_ "image/gif"
|
|
_ "image/png"
|
|
|
|
_ "github.com/strukturag/libheif/go/heif"
|
|
_ "golang.org/x/image/webp"
|
|
)
|
|
|
|
var (
|
|
jpegMagic = []byte{0xFF, 0xD8, 0xFF}
|
|
pngMagic = []byte{0x89, 0x50, 0x4E, 0x47}
|
|
gifMagic = []byte{0x47, 0x49, 0x46}
|
|
riffMagic = []byte{0x52, 0x49, 0x46, 0x46}
|
|
webpMagic = []byte{0x57, 0x45, 0x42, 0x50}
|
|
)
|
|
|
|
func ImgToJPEG(file io.ReadSeeker, outputPath string) error {
|
|
format, err := DetectImageFormat(file)
|
|
if err != nil {
|
|
return fmt.Errorf("failed to detect image format: %w", err)
|
|
}
|
|
|
|
outputFile, err := os.Create(outputPath)
|
|
if err != nil {
|
|
return fmt.Errorf("failed to create output file: %w", err)
|
|
}
|
|
defer outputFile.Close()
|
|
|
|
if format == "jpeg" {
|
|
if _, err = file.Seek(0, io.SeekStart); err != nil {
|
|
return fmt.Errorf("failed to reset file position: %w", err)
|
|
}
|
|
|
|
if _, err = io.Copy(outputFile, file); err != nil {
|
|
os.Remove(outputPath)
|
|
return fmt.Errorf("failed to copy image: %w", err)
|
|
}
|
|
return nil
|
|
}
|
|
|
|
if _, err = file.Seek(0, io.SeekStart); err != nil {
|
|
return fmt.Errorf("failed to reset file position: %w", err)
|
|
}
|
|
|
|
img, _, err := image.Decode(file)
|
|
if err != nil {
|
|
return fmt.Errorf("failed to decode image: %w", err)
|
|
}
|
|
|
|
err = jpeg.Encode(outputFile, img, nil)
|
|
if err != nil {
|
|
os.Remove(outputPath)
|
|
return fmt.Errorf("failed to encode image: %w", err)
|
|
}
|
|
|
|
return nil
|
|
}
|
|
|
|
func DetectImageFormat(file io.ReadSeeker) (string, error) {
|
|
header := make([]byte, 12)
|
|
|
|
_, err := file.Read(header)
|
|
if err != nil {
|
|
return "", fmt.Errorf("failed to read file header: %w", err)
|
|
}
|
|
if _, err = file.Seek(0, io.SeekStart); err != nil {
|
|
return "", fmt.Errorf("failed to reset file position: %w", err)
|
|
}
|
|
if len(header) < 12 {
|
|
return "", ErrFileTooShort
|
|
}
|
|
if bytes.HasPrefix(header, jpegMagic) {
|
|
return "jpeg", nil
|
|
}
|
|
|
|
if bytes.HasPrefix(header, pngMagic) {
|
|
return "png", nil
|
|
}
|
|
|
|
if bytes.HasPrefix(header, gifMagic) {
|
|
return "gif", nil
|
|
}
|
|
|
|
if isHEIF(header) {
|
|
return "heif", nil
|
|
}
|
|
|
|
if bytes.HasPrefix(header, riffMagic) {
|
|
if bytes.Equal(header[8:12], webpMagic) {
|
|
return "webp", nil
|
|
}
|
|
return "", ErrUnknownRIFF
|
|
}
|
|
|
|
return "", ErrUnsupportedImageFormat
|
|
}
|
|
|
|
func isHEIF(header []byte) bool {
|
|
if len(header) < 12 {
|
|
return false
|
|
}
|
|
isHeifHeader := header[0] == 0x00 && header[1] == 0x00 &&
|
|
header[2] == 0x00 && (header[3] == 0x18 || header[3] == 0x1C) &&
|
|
bytes.Equal(header[4:8], []byte("ftyp"))
|
|
if !isHeifHeader {
|
|
return false
|
|
}
|
|
heifBrands := []string{"heic", "heix", "mif1", "msf1"}
|
|
brand := string(header[8:12])
|
|
|
|
for _, b := range heifBrands {
|
|
if brand == b {
|
|
return true
|
|
}
|
|
}
|
|
return false
|
|
}
|