feat(meta): write album art & metadata into destination file

internal/ffmpeg/ffmpeg.go

@@ -10,6 +10,7 @@ import (
 	"strings"
 
 	"unlock-music.dev/cli/algo/common"
+	"unlock-music.dev/cli/internal/utils"
 )
 
 func ExtractAlbumArt(ctx context.Context, rd io.Reader) (*bytes.Buffer, error) {
@@ -33,8 +34,8 @@ func ExtractAlbumArt(ctx context.Context, rd io.Reader) (*bytes.Buffer, error) {
 }
 
 type UpdateMetadataParams struct {
-	Audio    io.Reader // required
-	AudioExt string    // required
+	Audio    string // required
+	AudioExt string // required
 
 	Meta common.AudioMeta // required
 
@@ -42,24 +43,15 @@ type UpdateMetadataParams struct {
 	AlbumArtExt string    // required if AlbumArt is not nil
 }
 
-func UpdateAudioMetadata(ctx context.Context, params *UpdateMetadataParams) (*bytes.Buffer, error) {
+func UpdateAudioMetadata(ctx context.Context, outPath string, params *UpdateMetadataParams) error {
 	builder := newFFmpegBuilder()
-	builder.SetFlag("y") // overwrite output file
 
-	out := newOutputBuilder("pipe:1")                        // use stdout as output
-	out.AddOption("f", encodeFormatFromExt(params.AudioExt)) // use mp3 muxer
+	out := newOutputBuilder(outPath) // output to file
+	builder.SetFlag("y")             // overwrite output file
 	builder.AddOutput(out)
 
-	// since ffmpeg doesn't support multiple input streams,
-	// we need to write the audio to a temp file
-	audioPath, err := writeTempFile(params.Audio, params.AudioExt)
-	if err != nil {
-		return nil, fmt.Errorf("updateAudioMeta write temp file: %w", err)
-	}
-	defer os.Remove(audioPath)
-
 	// input audio -> output audio
-	builder.AddInput(newInputBuilder(audioPath)) // input 0: audio
+	builder.AddInput(newInputBuilder(params.Audio)) // input 0: audio
 	out.AddOption("map", "0:a")
 	out.AddOption("codec:a", "copy")
 
@@ -68,9 +60,9 @@ func UpdateAudioMetadata(ctx context.Context, params *UpdateMetadataParams) (*by
 		params.AudioExt != ".wav" /* wav doesn't support attached image */ {
 
 		// write cover to temp file
-		artPath, err := writeTempFile(params.AlbumArt, params.AlbumArtExt)
+		artPath, err := utils.WriteTempFile(params.AlbumArt, params.AlbumArtExt)
 		if err != nil {
-			return nil, fmt.Errorf("updateAudioMeta write temp file: %w", err)
+			return fmt.Errorf("updateAudioMeta write temp file: %w", err)
 		}
 		defer os.Remove(artPath)
 
@@ -108,51 +100,10 @@ func UpdateAudioMetadata(ctx context.Context, params *UpdateMetadataParams) (*by
 
 	// execute ffmpeg
 	cmd := builder.Command(ctx)
-	stdout, stderr := &bytes.Buffer{}, &bytes.Buffer{}
-	cmd.Stdout, cmd.Stderr = stdout, stderr
 
-	if err := cmd.Run(); err != nil {
-		return nil, fmt.Errorf("ffmpeg run: %w", err)
+	if stdout, err := cmd.CombinedOutput(); err != nil {
+		return fmt.Errorf("ffmpeg run: %w, %s", err, string(stdout))
 	}
 
-	return stdout, nil
-}
-
-func writeTempFile(rd io.Reader, ext string) (string, error) {
-	audioFile, err := os.CreateTemp("", "*"+ext)
-	if err != nil {
-		return "", fmt.Errorf("ffmpeg create temp file: %w", err)
-	}
-
-	if _, err := io.Copy(audioFile, rd); err != nil {
-		return "", fmt.Errorf("ffmpeg write temp file: %w", err)
-	}
-
-	if err := audioFile.Close(); err != nil {
-		return "", fmt.Errorf("ffmpeg close temp file: %w", err)
-	}
-
-	return audioFile.Name(), nil
-}
-
-// encodeFormatFromExt returns the file format name the recognized & supporting encoding by ffmpeg.
-func encodeFormatFromExt(ext string) string {
-	switch ext {
-	case ".flac":
-		return "flac" // raw FLAC
-	case ".mp3":
-		return "mp3" // MP3 (MPEG audio layer 3)
-	case ".ogg":
-		return "ogg" // Ogg
-	case ".m4a":
-		return "ipod" // iPod H.264 MP4 (MPEG-4 Part 14)
-	case ".wav":
-		return "wav" // WAV / WAVE (Waveform Audio)
-	case ".aac":
-		return "adts" // ADTS AAC (Advanced Audio Coding)
-	case ".wma":
-		return "asf" // ASF (Advanced / Active Streaming Format)
-	default:
-		return ""
-	}
+	return nil
 }

internal/ffmpeg/ffprobe.go

@@ -1,6 +1,7 @@
 package ffmpeg
 
 import (
+	"bytes"
 	"context"
 	"encoding/json"
 	"io"
@@ -119,17 +120,20 @@ func ProbeReader(ctx context.Context, rd io.Reader) (*Result, error) {
 	cmd := exec.CommandContext(ctx, "ffprobe",
 		"-v", "quiet", // disable logging
 		"-print_format", "json", // use json format
-		"-show_format", "-show_streams", // retrieve format and streams
-		"-", // input from stdin
+		"-show_format", "-show_streams", "-show_error", // retrieve format and streams
+		"pipe:0", // input from stdin
 	)
+
 	cmd.Stdin = rd
-	out, err := cmd.Output()
-	if err != nil {
+	stdout, stderr := &bytes.Buffer{}, &bytes.Buffer{}
+	cmd.Stdout, cmd.Stderr = stdout, stderr
+
+	if err := cmd.Run(); err != nil {
 		return nil, err
 	}
 
 	ret := new(Result)
-	if err := json.Unmarshal(out, ret); err != nil {
+	if err := json.Unmarshal(stdout.Bytes(), ret); err != nil {
 		return nil, err
 	}
 

internal/utils/temp.go

@@ -0,0 +1,24 @@
+package utils
+
+import (
+	"fmt"
+	"io"
+	"os"
+)
+
+func WriteTempFile(rd io.Reader, ext string) (string, error) {
+	audioFile, err := os.CreateTemp("", "*"+ext)
+	if err != nil {
+		return "", fmt.Errorf("ffmpeg create temp file: %w", err)
+	}
+
+	if _, err := io.Copy(audioFile, rd); err != nil {
+		return "", fmt.Errorf("ffmpeg write temp file: %w", err)
+	}
+
+	if err := audioFile.Close(); err != nil {
+		return "", fmt.Errorf("ffmpeg close temp file: %w", err)
+	}
+
+	return audioFile.Name(), nil
+}