refactor(transcoding): update default command handling and add codec support for transcoding

Signed-off-by: Deluan <deluan@navidrome.org>

core/ffmpeg/ffmpeg.go

@@ -7,12 +7,12 @@ import (
 	"io"
 	"os"
 	"os/exec"
-	"slices"
 	"strconv"
 	"strings"
 	"sync"
 
 	"github.com/navidrome/navidrome/conf"
+	"github.com/navidrome/navidrome/consts"
 	"github.com/navidrome/navidrome/log"
 )
 
@@ -172,19 +172,6 @@ func (j *ffCmd) wait() {
 	_ = j.out.Close()
 }
 
-// defaultCommands maps format to the known default command templates.
-// Used to detect whether a user has customized their transcoding command.
-// Multiple entries per format support smooth upgrades (e.g. aac changed from adts to ipod).
-var defaultCommands = map[string][]string{
-	"mp3":  {"ffmpeg -i %s -ss %t -map 0:a:0 -b:a %bk -v 0 -f mp3 -"},
-	"opus": {"ffmpeg -i %s -ss %t -map 0:a:0 -b:a %bk -v 0 -c:a libopus -f opus -"},
-	"aac": {
-		"ffmpeg -i %s -ss %t -map 0:a:0 -b:a %bk -v 0 -c:a aac -f ipod -movflags frag_keyframe+empty_moov -",
-		"ffmpeg -i %s -ss %t -map 0:a:0 -b:a %bk -v 0 -c:a aac -f adts -", // legacy default
-	},
-	"flac": {"ffmpeg -i %s -ss %t -map 0:a:0 -v 0 -c:a flac -f flac -"},
-}
-
 // formatCodecMap maps target format to ffmpeg codec flag.
 var formatCodecMap = map[string]string{
 	"mp3":  "libmp3lame",
@@ -201,9 +188,18 @@ var formatOutputMap = map[string]string{
 	"flac": "flac",
 }
 
-// isDefaultCommand returns true if the command matches any known default for this format.
+// defaultCommands is used to detect whether a user has customized their transcoding command.
+var defaultCommands = func() map[string]string {
+	m := make(map[string]string, len(consts.DefaultTranscodings))
+	for _, t := range consts.DefaultTranscodings {
+		m[t.TargetFormat] = t.Command
+	}
+	return m
+}()
+
+// isDefaultCommand returns true if the command matches the known default for this format.
 func isDefaultCommand(format, command string) bool {
-	return slices.Contains(defaultCommands[format], command)
+	return defaultCommands[format] == command
 }
 
 // buildDynamicArgs programmatically constructs ffmpeg arguments for known formats,

core/ffmpeg/ffmpeg_test.go

@@ -88,9 +88,6 @@ var _ = Describe("ffmpeg", func() {
 		It("returns true for known default aac command", func() {
 			Expect(isDefaultCommand("aac", "ffmpeg -i %s -ss %t -map 0:a:0 -b:a %bk -v 0 -c:a aac -f ipod -movflags frag_keyframe+empty_moov -")).To(BeTrue())
 		})
-		It("returns true for legacy default aac command", func() {
-			Expect(isDefaultCommand("aac", "ffmpeg -i %s -ss %t -map 0:a:0 -b:a %bk -v 0 -c:a aac -f adts -")).To(BeTrue())
-		})
 		It("returns true for known default flac command", func() {
 			Expect(isDefaultCommand("flac", "ffmpeg -i %s -ss %t -map 0:a:0 -v 0 -c:a flac -f flac -")).To(BeTrue())
 		})

db/migrations/20260205120000_add_codec_and_update_transcodings.go

@@ -0,0 +1,63 @@
+package migrations
+
+import (
+	"context"
+	"database/sql"
+
+	"github.com/navidrome/navidrome/model/id"
+	"github.com/pressly/goose/v3"
+)
+
+func init() {
+	goose.AddMigrationContext(upAddCodecAndUpdateTranscodings, downAddCodecAndUpdateTranscodings)
+}
+
+func upAddCodecAndUpdateTranscodings(_ context.Context, tx *sql.Tx) error {
+	// Add codec column to media_file.
+	_, err := tx.Exec(`ALTER TABLE media_file ADD COLUMN codec VARCHAR(255) DEFAULT '' NOT NULL`)
+	if err != nil {
+		return err
+	}
+	_, err = tx.Exec(`CREATE INDEX IF NOT EXISTS media_file_codec ON media_file(codec)`)
+	if err != nil {
+		return err
+	}
+
+	// Update old AAC default (adts) to new default (ipod with fragmented MP4).
+	// Only affects users who still have the unmodified old default command.
+	_, err = tx.Exec(
+		`UPDATE transcoding SET command = ? WHERE target_format = 'aac' AND command = ?`,
+		"ffmpeg -i %s -ss %t -map 0:a:0 -b:a %bk -v 0 -c:a aac -f ipod -movflags frag_keyframe+empty_moov -",
+		"ffmpeg -i %s -ss %t -map 0:a:0 -b:a %bk -v 0 -c:a aac -f adts -",
+	)
+	if err != nil {
+		return err
+	}
+
+	// Add FLAC transcoding for existing installations that were seeded before FLAC was added.
+	var count int
+	err = tx.QueryRow("SELECT COUNT(*) FROM transcoding WHERE target_format = 'flac'").Scan(&count)
+	if err != nil {
+		return err
+	}
+	if count == 0 {
+		_, err = tx.Exec(
+			"INSERT INTO transcoding (id, name, target_format, default_bit_rate, command) VALUES (?, ?, ?, ?, ?)",
+			id.NewRandom(), "flac audio", "flac", 0,
+			"ffmpeg -i %s -ss %t -map 0:a:0 -v 0 -c:a flac -f flac -",
+		)
+		if err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+func downAddCodecAndUpdateTranscodings(_ context.Context, tx *sql.Tx) error {
+	_, err := tx.Exec(`DROP INDEX IF EXISTS media_file_codec`)
+	if err != nil {
+		return err
+	}
+	_, err = tx.Exec(`ALTER TABLE media_file DROP COLUMN codec`)
+	return err
+}

db/migrations/20260205120000_add_codec_to_media_file.sql

@@ -1,11 +0,0 @@
--- +goose Up
--- +goose StatementBegin
-ALTER TABLE media_file ADD COLUMN codec VARCHAR(255) DEFAULT '' NOT NULL;
-CREATE INDEX IF NOT EXISTS media_file_codec ON media_file(codec);
--- +goose StatementEnd
-
--- +goose Down
--- +goose StatementBegin
-DROP INDEX IF EXISTS media_file_codec;
-ALTER TABLE media_file DROP COLUMN codec;
--- +goose StatementEnd