Add thumbnail download command

client.go

@@ -7,13 +7,12 @@ import (
 	"errors"
 	"fmt"
 	"io"
+	"log/slog"
 	"math/rand"
 	"net/http"
 	"net/url"
 	"strconv"
 	"sync/atomic"
-
-	"log/slog"
 )
 
 const (
@@ -25,7 +24,8 @@ const (
 )
 
 var (
-	ErrNoFormat = errors.New("no video format provided")
+	ErrNoFormat    = errors.New("no video format provided")
+	ErrNoThumbnail = errors.New("no thumbnail found")
 )
 
 // DefaultClient type to use. No reason to change but you could if you wanted to.
@@ -72,6 +72,30 @@ func (c *Client) GetVideoContext(ctx context.Context, url string) (*Video, error
 	return c.videoFromID(ctx, id)
 }
 
+// GetThumbnail returns the thumbnail image for a video.
+func (c *Client) GetThumbnail(thumbnails Thumbnails) (io.ReadCloser, string, error) {
+	return c.GetThumbnailContext(context.Background(), thumbnails)
+}
+
+// GetThumbnailContext returns the thumbnail image for a video with a context.
+func (c *Client) GetThumbnailContext(ctx context.Context, thumbnails Thumbnails) (io.ReadCloser, string, error) {
+	c.assureClient()
+
+	for _, thumbnail := range thumbnails {
+		resp, err := c.httpGet(ctx, thumbnail.URL)
+		if errors.Is(err, ErrUnexpectedStatusCode(http.StatusNotFound)) {
+			continue
+		}
+		if err != nil {
+			return nil, "", err
+		}
+
+		return resp.Body, resp.Header.Get("Content-Type"), nil
+	}
+
+	return nil, "", ErrNoThumbnail
+}
+
 func (c *Client) videoFromID(ctx context.Context, id string) (*Video, error) {
 	c.assureClient()
 

cmd/youtubedr/download.go

@@ -56,7 +56,7 @@ func download(id string) error {
 func checkFFMPEG() error {
 	fmt.Println("check ffmpeg is installed....")
 	if err := exec.Command("ffmpeg", "-version").Run(); err != nil {
-		ffmpegCheck = fmt.Errorf("please check ffmpegCheck is installed correctly")
+		ffmpegCheck = fmt.Errorf("please check that ffmpeg is installed correctly")
 	}
 
 	return ffmpegCheck

cmd/youtubedr/thumbnail.go

@@ -0,0 +1,135 @@
+package main
+
+import (
+	"fmt"
+	"io"
+	"os"
+	"os/exec"
+	"path/filepath"
+
+	"github.com/kkdai/youtube/v2"
+	"github.com/spf13/cobra"
+)
+
+var thumbnailCmd = &cobra.Command{
+	Use:     "thumbnail",
+	Short:   "Downloads a thumbnail from youtube",
+	Example: `youtubedr thumbnail -n maxresdefault -o thumbnail.png https://www.youtube.com/watch\?v\=TGqoAUaivOY`,
+	Args:    cobra.ExactArgs(1),
+	Run: func(_ *cobra.Command, args []string) {
+		exitOnError(downloadThumbnail(args[0]))
+	},
+}
+
+var (
+	thumbnailName string
+	noExtend      bool
+)
+
+func init() {
+	rootCmd.AddCommand(thumbnailCmd)
+
+	thumbnailCmd.Flags().StringVarP(&outputFile, "filename", "o", "", "the output file, the default is generated by the video title")
+	thumbnailCmd.Flags().StringVarP(&outputDir, "directory", "d", ".", "the output directory")
+	thumbnailCmd.Flags().StringVarP(&thumbnailName, "name", "n", "", "the thumbnail name (ex. \"maxresdefault\")")
+	thumbnailCmd.Flags().BoolVarP(&noExtend, "known-only", "k", false, "only try thumbnails received in video response (lower quality)")
+}
+
+func downloadThumbnail(url string) error {
+	downloader := getDownloader()
+	video, err := downloader.GetVideo(url)
+
+	if err != nil {
+		return err
+	}
+
+	thumbnails := video.Thumbnails
+	if !noExtend {
+		thumbnails = thumbnails.Extended(video.ID)
+	}
+	if thumbnailName != "" {
+		thumbnails = thumbnails.FilterName(thumbnailName)
+	}
+	thumbnails.Sort()
+
+	if outputFile == "" {
+		return downloadAnyFormat(video.ID, thumbnails)
+	}
+
+	ext := filepath.Ext(outputFile)
+	switch ext {
+	case ".jpg", ".jpeg":
+		thumbnails = thumbnails.FilterExt(".jpg")
+	case ".webp":
+		thumbnails = thumbnails.FilterExt(".webp")
+	default:
+		return downloadAndEncode(thumbnails)
+	}
+
+	return downloadAnyFormat(video.ID, thumbnails)
+}
+
+func downloadAnyFormat(videoID string, thumbnails youtube.Thumbnails) error {
+	image, mimeType, err := downloader.GetThumbnail(thumbnails)
+
+	if err != nil {
+		return err
+	}
+
+	defer image.Close()
+
+	var f *os.File
+
+	if outputFile == "" {
+		switch mimeType {
+		case "image/jpeg":
+			f, err = os.Create(filepath.Join(outputDir, fmt.Sprintf("%s.jpg", videoID)))
+		case "image/webp":
+			f, err = os.Create(filepath.Join(outputDir, fmt.Sprintf("%s.webp", videoID)))
+		default:
+			return fmt.Errorf("unknown content type: %s", mimeType)
+		}
+	} else {
+		f, err = os.Create(filepath.Join(outputDir, outputFile))
+	}
+
+	if err != nil {
+		return err
+	}
+
+	defer f.Close()
+
+	if _, err := io.Copy(f, image); err != nil {
+		return err
+	}
+
+	return nil
+}
+
+func downloadAndEncode(thumbnails youtube.Thumbnails) error {
+	if err := checkFFMPEG(); err != nil {
+		return err
+	}
+
+	image, _, err := downloader.GetThumbnail(thumbnails)
+	if err != nil {
+		return err
+	}
+
+	defer image.Close()
+
+	//nolint:gosec
+	ffmpeg := exec.Command("ffmpeg",
+		"-i", "-",
+		"-update", "true",
+		"-frames:v", "1",
+		filepath.Join(outputDir, outputFile),
+		"-loglevel", "warning",
+	)
+
+	ffmpeg.Stdin = image
+	ffmpeg.Stdout = os.Stdout
+	ffmpeg.Stderr = os.Stderr
+
+	return ffmpeg.Run()
+}

response_data.go

@@ -133,8 +133,6 @@ func (f *Format) LanguageDisplayName() string {
 	return f.AudioTrack.DisplayName
 }
 
-type Thumbnails []Thumbnail
-
 type Thumbnail struct {
 	URL    string
 	Width  uint