list formats and provide them for download

app/ytdlp.go

@@ -2,6 +2,7 @@ package main
 
 import (
 	"context"
+	"encoding/json"
 	"time"
 
 	"github.com/lrstanley/go-ytdlp"
@@ -10,6 +11,29 @@ import (
 type DownloadOptions struct {
 	EmbedThumbnail   bool
 	IncludeSubtitles bool
+	VideoFormatID    string
+	AudioFormatID    string
+}
+
+type VideoOption struct {
+	Height     *int     `json:"height,omitempty"`
+	Resolution string   `json:"resolution,omitempty"`
+	FormatID   string   `json:"format_id"`
+	Ext        string   `json:"ext"`
+	TBR        *float64 `json:"tbr,omitempty"`
+}
+
+type AudioOption struct {
+	Format   string   `json:"format"`
+	FormatID string   `json:"format_id"`
+	Ext      string   `json:"ext"`
+	TBR      *float64 `json:"tbr,omitempty"`
+	Language *string  `json:"language,omitempty"`
+}
+
+type FormatOptions struct {
+	VideoOptions []VideoOption `json:"video_options"`
+	AudioOptions []AudioOption `json:"audio_options"`
 }
 
 type ProgressUpdate struct {
@@ -20,6 +44,89 @@ type ProgressUpdate struct {
 	Phase    string
 }
 
+func GetFormats(url string) (*FormatOptions, error) {
+	dl := ytdlp.New().
+		SkipDownload().
+		DumpJSON()
+
+	result, err := dl.Run(context.TODO(), url)
+	if err != nil {
+		return nil, err
+	}
+
+	// Parse the JSON output
+	var info struct {
+		Formats []struct {
+			VCodec       *string  `json:"vcodec"`
+			ACodec       *string  `json:"acodec"`
+			NeedsTesting *bool    `json:"__needs_testing"`
+			Height       *int     `json:"height"`
+			Resolution   string   `json:"resolution"`
+			FormatID     string   `json:"format_id"`
+			Format       string   `json:"format"`
+			Ext          string   `json:"ext"`
+			TBR          *float64 `json:"tbr"`
+			Language     *string  `json:"language"`
+			LanguagePref *int     `json:"language_preference"`
+			URL          *string  `json:"url"`
+			Protocol     *string  `json:"protocol"`
+		} `json:"formats"`
+	}
+
+	if err := json.Unmarshal([]byte(result.Stdout), &info); err != nil {
+		return nil, err
+	}
+
+	formatOpts := &FormatOptions{
+		VideoOptions: []VideoOption{},
+		AudioOptions: []AudioOption{},
+	}
+
+	for _, fmt := range info.Formats {
+		// Skip formats that need testing
+		if fmt.NeedsTesting != nil && *fmt.NeedsTesting {
+			continue
+		}
+
+		// Skip SABR formats (https://github.com/yt-dlp/yt-dlp/issues/12482)
+		if fmt.URL == nil || *fmt.URL == "" {
+			continue
+		}
+
+		// Video-only: has video codec but no audio codec
+		if fmt.VCodec != nil && *fmt.VCodec != "none" &&
+			fmt.ACodec != nil && *fmt.ACodec == "none" {
+			formatOpts.VideoOptions = append(formatOpts.VideoOptions, VideoOption{
+				Height:     fmt.Height,
+				Resolution: fmt.Resolution,
+				FormatID:   fmt.FormatID,
+				Ext:        fmt.Ext,
+				TBR:        fmt.TBR,
+			})
+		}
+
+		// Audio-only: has audio codec but no video codec
+		if fmt.ACodec != nil && *fmt.ACodec != "none" &&
+			fmt.VCodec != nil && *fmt.VCodec == "none" {
+			audioOpt := AudioOption{
+				Format:   fmt.Format,
+				FormatID: fmt.FormatID,
+				Ext:      fmt.Ext,
+				TBR:      fmt.TBR,
+			}
+
+			// Use language if available, otherwise use language_preference
+			if fmt.Language != nil {
+				audioOpt.Language = fmt.Language
+			}
+
+			formatOpts.AudioOptions = append(formatOpts.AudioOptions, audioOpt)
+		}
+	}
+
+	return formatOpts, nil
+}
+
 func downloadVideo(out_dir, url string, opts DownloadOptions, progressChan chan<- ProgressUpdate) {
 	defer close(progressChan)
 
@@ -27,7 +134,6 @@ func downloadVideo(out_dir, url string, opts DownloadOptions, progressChan chan<
 
 	dl := ytdlp.New().
 		SetWorkDir(out_dir).
-		FormatSort("res,ext:mp4:m4a").
 		RecodeVideo("mp4").
 		ProgressFunc(100*time.Millisecond, func(prog ytdlp.ProgressUpdate) {
 			// Detect phase transition -- differentiate "downloading" as the main download
@@ -54,6 +160,18 @@ func downloadVideo(out_dir, url string, opts DownloadOptions, progressChan chan<
 		}).
 		Output("%(title)s.%(ext)s")
 
+	// Set format if both video and audio format IDs are provided
+	if opts.VideoFormatID != "" && opts.AudioFormatID != "" {
+		dl = dl.Format(opts.VideoFormatID + "+" + opts.AudioFormatID)
+	} else if opts.VideoFormatID != "" {
+		dl = dl.Format(opts.VideoFormatID)
+	} else if opts.AudioFormatID != "" {
+		dl = dl.Format(opts.AudioFormatID)
+	} else {
+		// Default format selection if none specified
+		dl = dl.FormatSort("res,ext:mp4:m4a")
+	}
+
 	if opts.EmbedThumbnail {
 		dl = dl.EmbedThumbnail()
 	}