feat: improve SAF file descriptor handling and Android platform compatibility

- Migrate MainActivity from FlutterActivity to FlutterFragmentActivity for SAF picker compatibility
- Add ImpellerAwareFlutterFragment to support Impeller fallback on legacy devices
- Add output_fd support in Go backend for direct file descriptor writes (SAF)
- Add helper functions in output_fd.go for FD-based file operations
- Refactor Tidal/Qobuz/Amazon downloaders to support FD output and skip metadata embedding for SAF (handled by Flutter)
- Add extractQobuzDownloadURLFromBody with unit tests for robust URL parsing
- Add storage mode picker (SAF vs App folder) in download settings for Android
- Fix FFmpeg output path building to avoid same-path conflicts
- Embed metadata to SAF FLAC files via temp file bridge in Flutter
- Upgrade Gradle wrapper to 9.3.1 and add activity-ktx dependency

go_backend/amazon.go

@@ -149,7 +149,7 @@ func (a *AmazonDownloader) downloadFromAfkarXYZ(amazonURL string) (string, strin
 	return downloadURL, fileName, nil
 }
 
-func (a *AmazonDownloader) DownloadFile(downloadURL, outputPath, itemID string) error {
+func (a *AmazonDownloader) DownloadFile(downloadURL, outputPath string, outputFD int, itemID string) error {
 	ctx := context.Background()
 
 	if itemID != "" {
@@ -188,7 +188,7 @@ func (a *AmazonDownloader) DownloadFile(downloadURL, outputPath, itemID string)
 		SetItemBytesTotal(itemID, expectedSize)
 	}
 
-	out, err := os.Create(outputPath)
+	out, err := openOutputForWrite(outputPath, outputFD)
 	if err != nil {
 		return err
 	}
@@ -207,23 +207,23 @@ func (a *AmazonDownloader) DownloadFile(downloadURL, outputPath, itemID string)
 	closeErr := out.Close()
 
 	if err != nil {
-		os.Remove(outputPath)
+		cleanupOutputOnError(outputPath, outputFD)
 		if isDownloadCancelled(itemID) {
 			return ErrDownloadCancelled
 		}
 		return fmt.Errorf("download interrupted: %w", err)
 	}
 	if flushErr != nil {
-		os.Remove(outputPath)
+		cleanupOutputOnError(outputPath, outputFD)
 		return fmt.Errorf("failed to flush buffer: %w", flushErr)
 	}
 	if closeErr != nil {
-		os.Remove(outputPath)
+		cleanupOutputOnError(outputPath, outputFD)
 		return fmt.Errorf("failed to close file: %w", closeErr)
 	}
 
 	if expectedSize > 0 && written != expectedSize {
-		os.Remove(outputPath)
+		cleanupOutputOnError(outputPath, outputFD)
 		return fmt.Errorf("incomplete download: expected %d bytes, got %d bytes", expectedSize, written)
 	}
 
@@ -249,7 +249,7 @@ type AmazonDownloadResult struct {
 func downloadFromAmazon(req DownloadRequest) (AmazonDownloadResult, error) {
 	downloader := NewAmazonDownloader()
 
-	isSafOutput := strings.TrimSpace(req.OutputPath) != ""
+	isSafOutput := isFDOutput(req.OutputFD) || strings.TrimSpace(req.OutputPath) != ""
 	if !isSafOutput {
 		if existingFile, exists := checkISRCExistsInternal(req.OutputDir, req.ISRC); exists {
 			return AmazonDownloadResult{FilePath: "EXISTS:" + existingFile}, nil
@@ -317,6 +317,9 @@ func downloadFromAmazon(req DownloadRequest) (AmazonDownloadResult, error) {
 	var outputPath string
 	if isSafOutput {
 		outputPath = strings.TrimSpace(req.OutputPath)
+		if outputPath == "" && isFDOutput(req.OutputFD) {
+			outputPath = fmt.Sprintf("/proc/self/fd/%d", req.OutputFD)
+		}
 	} else {
 		filename = sanitizeFilename(filename) + ".flac"
 		outputPath = filepath.Join(req.OutputDir, filename)
@@ -342,7 +345,7 @@ func downloadFromAmazon(req DownloadRequest) (AmazonDownloadResult, error) {
 	}()
 
 	// Download audio file with item ID for progress tracking
-	if err := downloader.DownloadFile(downloadURL, outputPath, req.ItemID); err != nil {
+	if err := downloader.DownloadFile(downloadURL, outputPath, req.OutputFD, req.ItemID); err != nil {
 		if errors.Is(err, ErrDownloadCancelled) {
 			return AmazonDownloadResult{}, ErrDownloadCancelled
 		}
@@ -415,54 +418,63 @@ func downloadFromAmazon(req DownloadRequest) (AmazonDownloadResult, error) {
 		}
 	}
 
-	if err := EmbedMetadataWithCoverData(outputPath, metadata, coverData); err != nil {
-		GoLog("[Amazon] Warning: failed to embed metadata: %v\n", err)
-	}
-
-	if req.EmbedLyrics && parallelResult != nil && parallelResult.LyricsLRC != "" {
-		lyricsMode := req.LyricsMode
-		if lyricsMode == "" {
-			lyricsMode = "embed"
+	if isSafOutput {
+		GoLog("[Amazon] SAF output detected - skipping in-backend metadata/lyrics embedding (handled in Flutter)\n")
+	} else {
+		if err := EmbedMetadataWithCoverData(outputPath, metadata, coverData); err != nil {
+			GoLog("[Amazon] Warning: failed to embed metadata: %v\n", err)
 		}
 
-		if !isSafOutput && (lyricsMode == "external" || lyricsMode == "both") {
-			GoLog("[Amazon] Saving external LRC file...\n")
-			if lrcPath, lrcErr := SaveLRCFile(outputPath, parallelResult.LyricsLRC); lrcErr != nil {
-				GoLog("[Amazon] Warning: failed to save LRC file: %v\n", lrcErr)
-			} else {
-				GoLog("[Amazon] LRC file saved: %s\n", lrcPath)
+		if req.EmbedLyrics && parallelResult != nil && parallelResult.LyricsLRC != "" {
+			lyricsMode := req.LyricsMode
+			if lyricsMode == "" {
+				lyricsMode = "embed"
 			}
-		}
 
-		if lyricsMode == "embed" || lyricsMode == "both" {
-			GoLog("[Amazon] Embedding parallel-fetched lyrics (%d lines)...\n", len(parallelResult.LyricsData.Lines))
-			if embedErr := EmbedLyrics(outputPath, parallelResult.LyricsLRC); embedErr != nil {
-				GoLog("[Amazon] Warning: failed to embed lyrics: %v\n", embedErr)
-			} else {
-				GoLog("[Amazon] Lyrics embedded successfully\n")
+			if lyricsMode == "external" || lyricsMode == "both" {
+				GoLog("[Amazon] Saving external LRC file...\n")
+				if lrcPath, lrcErr := SaveLRCFile(outputPath, parallelResult.LyricsLRC); lrcErr != nil {
+					GoLog("[Amazon] Warning: failed to save LRC file: %v\n", lrcErr)
+				} else {
+					GoLog("[Amazon] LRC file saved: %s\n", lrcPath)
+				}
 			}
+
+			if lyricsMode == "embed" || lyricsMode == "both" {
+				GoLog("[Amazon] Embedding parallel-fetched lyrics (%d lines)...\n", len(parallelResult.LyricsData.Lines))
+				if embedErr := EmbedLyrics(outputPath, parallelResult.LyricsLRC); embedErr != nil {
+					GoLog("[Amazon] Warning: failed to embed lyrics: %v\n", embedErr)
+				} else {
+					GoLog("[Amazon] Lyrics embedded successfully\n")
+				}
+			}
+		} else if req.EmbedLyrics {
+			GoLog("[Amazon] No lyrics available from parallel fetch\n")
 		}
-	} else if req.EmbedLyrics {
-		GoLog("[Amazon] No lyrics available from parallel fetch\n")
 	}
 
 	GoLog("[Amazon] Downloaded successfully from Amazon Music\n")
 
-	quality, err := GetAudioQuality(outputPath)
-	if err != nil {
-		GoLog("[Amazon] Warning: couldn't read quality from file: %v\n", err)
+	quality := AudioQuality{}
+	if isSafOutput {
+		GoLog("[Amazon] SAF output detected - skipping post-write file inspection in backend\n")
 	} else {
-		GoLog("[Amazon] Actual quality: %d-bit/%dHz\n", quality.BitDepth, quality.SampleRate)
-	}
+		quality, err = GetAudioQuality(outputPath)
+		if err != nil {
+			GoLog("[Amazon] Warning: couldn't read quality from file: %v\n", err)
+		} else {
+			GoLog("[Amazon] Actual quality: %d-bit/%dHz\n", quality.BitDepth, quality.SampleRate)
+		}
 
-	finalMeta, metaReadErr := ReadMetadata(outputPath)
-	if metaReadErr == nil && finalMeta != nil {
-		GoLog("[Amazon] Final metadata from file - Track: %d, Disc: %d, Date: %s\n",
-			finalMeta.TrackNumber, finalMeta.DiscNumber, finalMeta.Date)
-		actualTrackNum = finalMeta.TrackNumber
-		actualDiscNum = finalMeta.DiscNumber
-		if finalMeta.Date != "" {
-			req.ReleaseDate = finalMeta.Date
+		finalMeta, metaReadErr := ReadMetadata(outputPath)
+		if metaReadErr == nil && finalMeta != nil {
+			GoLog("[Amazon] Final metadata from file - Track: %d, Disc: %d, Date: %s\n",
+				finalMeta.TrackNumber, finalMeta.DiscNumber, finalMeta.Date)
+			actualTrackNum = finalMeta.TrackNumber
+			actualDiscNum = finalMeta.DiscNumber
+			if finalMeta.Date != "" {
+				req.ReleaseDate = finalMeta.Date
+			}
 		}
 	}
 

go_backend/exports.go

@@ -129,6 +129,7 @@ type DownloadRequest struct {
 	CoverURL             string `json:"cover_url"`
 	OutputDir            string `json:"output_dir"`
 	OutputPath           string `json:"output_path,omitempty"`
+	OutputFD             int    `json:"output_fd,omitempty"`
 	OutputExt            string `json:"output_ext,omitempty"`
 	FilenameFormat       string `json:"filename_format"`
 	Quality              string `json:"quality"`
@@ -204,7 +205,7 @@ func DownloadTrack(requestJSON string) (string, error) {
 	req.OutputPath = strings.TrimSpace(req.OutputPath)
 	req.OutputExt = strings.TrimSpace(req.OutputExt)
 
-	if req.OutputPath == "" && req.OutputDir != "" {
+	if req.OutputPath == "" && req.OutputFD <= 0 && req.OutputDir != "" {
 		AddAllowedDownloadDir(req.OutputDir)
 	}
 
@@ -345,7 +346,7 @@ func DownloadWithFallback(requestJSON string) (string, error) {
 	req.OutputPath = strings.TrimSpace(req.OutputPath)
 	req.OutputExt = strings.TrimSpace(req.OutputExt)
 
-	if req.OutputPath == "" && req.OutputDir != "" {
+	if req.OutputPath == "" && req.OutputFD <= 0 && req.OutputDir != "" {
 		AddAllowedDownloadDir(req.OutputDir)
 	}
 
@@ -1285,7 +1286,7 @@ func DownloadWithExtensionsJSON(requestJSON string) (string, error) {
 	req.OutputDir = strings.TrimSpace(req.OutputDir)
 	req.OutputPath = strings.TrimSpace(req.OutputPath)
 	req.OutputExt = strings.TrimSpace(req.OutputExt)
-	if req.OutputPath == "" && req.OutputDir != "" {
+	if req.OutputPath == "" && req.OutputFD <= 0 && req.OutputDir != "" {
 		AddAllowedDownloadDir(req.OutputDir)
 	}
 

go_backend/output_fd.go

@@ -0,0 +1,31 @@
+package gobackend
+
+import (
+	"fmt"
+	"os"
+	"strings"
+)
+
+func isFDOutput(outputFD int) bool {
+	return outputFD > 0
+}
+
+func openOutputForWrite(outputPath string, outputFD int) (*os.File, error) {
+	if isFDOutput(outputFD) {
+		return os.NewFile(uintptr(outputFD), fmt.Sprintf("saf_fd_%d", outputFD)), nil
+	}
+	return os.Create(outputPath)
+}
+
+func cleanupOutputOnError(outputPath string, outputFD int) {
+	if isFDOutput(outputFD) {
+		return
+	}
+
+	path := strings.TrimSpace(outputPath)
+	if path == "" || strings.HasPrefix(path, "/proc/self/fd/") {
+		return
+	}
+
+	_ = os.Remove(path)
+}

go_backend/qobuz.go

@@ -380,6 +380,42 @@ func decodeXOR(data []byte) string {
 	return string(result)
 }
 
+func extractQobuzDownloadURLFromBody(body []byte) (string, error) {
+	var raw map[string]any
+	if err := json.Unmarshal(body, &raw); err != nil {
+		return "", fmt.Errorf("invalid JSON: %v", err)
+	}
+
+	if errMsg, ok := raw["error"].(string); ok && strings.TrimSpace(errMsg) != "" {
+		return "", fmt.Errorf("%s", errMsg)
+	}
+
+	if success, ok := raw["success"].(bool); ok && !success {
+		if msg, ok := raw["message"].(string); ok && strings.TrimSpace(msg) != "" {
+			return "", fmt.Errorf("%s", msg)
+		}
+		return "", fmt.Errorf("api returned success=false")
+	}
+
+	if urlVal, ok := raw["url"].(string); ok && strings.TrimSpace(urlVal) != "" {
+		return strings.TrimSpace(urlVal), nil
+	}
+	if linkVal, ok := raw["link"].(string); ok && strings.TrimSpace(linkVal) != "" {
+		return strings.TrimSpace(linkVal), nil
+	}
+
+	if data, ok := raw["data"].(map[string]any); ok {
+		if urlVal, ok := data["url"].(string); ok && strings.TrimSpace(urlVal) != "" {
+			return strings.TrimSpace(urlVal), nil
+		}
+		if linkVal, ok := data["link"].(string); ok && strings.TrimSpace(linkVal) != "" {
+			return strings.TrimSpace(linkVal), nil
+		}
+	}
+
+	return "", fmt.Errorf("no download URL in response")
+}
+
 func (q *QobuzDownloader) downloadFromJumo(trackID int64, quality string) (string, error) {
 	formatID := mapJumoQuality(quality)
 	region := "US"
@@ -810,27 +846,12 @@ func fetchQobuzURLWithRetry(api string, trackID int64, quality string, timeout t
 			return "", fmt.Errorf("received HTML instead of JSON")
 		}
 
-		var errorResp struct {
-			Error string `json:"error"`
+		urlVal, parseErr := extractQobuzDownloadURLFromBody(body)
+		if parseErr == nil {
+			return urlVal, nil
 		}
-		if json.Unmarshal(body, &errorResp) == nil && errorResp.Error != "" {
-			// API-level errors are usually not retryable (track not found, etc.)
-			return "", fmt.Errorf("%s", errorResp.Error)
-		}
-
-		var result struct {
-			URL string `json:"url"`
-		}
-		if err := json.Unmarshal(body, &result); err != nil {
-			lastErr = fmt.Errorf("invalid JSON: %v", err)
-			continue
-		}
-
-		if result.URL != "" {
-			return result.URL, nil
-		}
-
-		return "", fmt.Errorf("no download URL in response")
+		lastErr = parseErr
+		continue
 	}
 
 	if lastErr != nil {
@@ -926,7 +947,7 @@ func (q *QobuzDownloader) GetDownloadURL(trackID int64, quality string) (string,
 	return "", fmt.Errorf("all Qobuz APIs and Jumo fallback failed: %w", err)
 }
 
-func (q *QobuzDownloader) DownloadFile(downloadURL, outputPath, itemID string) error {
+func (q *QobuzDownloader) DownloadFile(downloadURL, outputPath string, outputFD int, itemID string) error {
 	ctx := context.Background()
 
 	if itemID != "" {
@@ -963,7 +984,7 @@ func (q *QobuzDownloader) DownloadFile(downloadURL, outputPath, itemID string) e
 		SetItemBytesTotal(itemID, expectedSize)
 	}
 
-	out, err := os.Create(outputPath)
+	out, err := openOutputForWrite(outputPath, outputFD)
 	if err != nil {
 		return err
 	}
@@ -982,23 +1003,23 @@ func (q *QobuzDownloader) DownloadFile(downloadURL, outputPath, itemID string) e
 	closeErr := out.Close()
 
 	if err != nil {
-		os.Remove(outputPath)
+		cleanupOutputOnError(outputPath, outputFD)
 		if isDownloadCancelled(itemID) {
 			return ErrDownloadCancelled
 		}
 		return fmt.Errorf("download interrupted: %w", err)
 	}
 	if flushErr != nil {
-		os.Remove(outputPath)
+		cleanupOutputOnError(outputPath, outputFD)
 		return fmt.Errorf("failed to flush buffer: %w", flushErr)
 	}
 	if closeErr != nil {
-		os.Remove(outputPath)
+		cleanupOutputOnError(outputPath, outputFD)
 		return fmt.Errorf("failed to close file: %w", closeErr)
 	}
 
 	if expectedSize > 0 && written != expectedSize {
-		os.Remove(outputPath)
+		cleanupOutputOnError(outputPath, outputFD)
 		return fmt.Errorf("incomplete download: expected %d bytes, got %d bytes", expectedSize, written)
 	}
 
@@ -1022,7 +1043,7 @@ type QobuzDownloadResult struct {
 func downloadFromQobuz(req DownloadRequest) (QobuzDownloadResult, error) {
 	downloader := NewQobuzDownloader()
 
-	isSafOutput := strings.TrimSpace(req.OutputPath) != ""
+	isSafOutput := isFDOutput(req.OutputFD) || strings.TrimSpace(req.OutputPath) != ""
 	if !isSafOutput {
 		if existingFile, exists := checkISRCExistsInternal(req.OutputDir, req.ISRC); exists {
 			return QobuzDownloadResult{FilePath: "EXISTS:" + existingFile}, nil
@@ -1137,6 +1158,9 @@ func downloadFromQobuz(req DownloadRequest) (QobuzDownloadResult, error) {
 	var outputPath string
 	if isSafOutput {
 		outputPath = strings.TrimSpace(req.OutputPath)
+		if outputPath == "" && isFDOutput(req.OutputFD) {
+			outputPath = fmt.Sprintf("/proc/self/fd/%d", req.OutputFD)
+		}
 	} else {
 		filename = sanitizeFilename(filename) + ".flac"
 		outputPath = filepath.Join(req.OutputDir, filename)
@@ -1180,7 +1204,7 @@ func downloadFromQobuz(req DownloadRequest) (QobuzDownloadResult, error) {
 		)
 	}()
 
-	if err := downloader.DownloadFile(downloadURL, outputPath, req.ItemID); err != nil {
+	if err := downloader.DownloadFile(downloadURL, outputPath, req.OutputFD, req.ItemID); err != nil {
 		if errors.Is(err, ErrDownloadCancelled) {
 			return QobuzDownloadResult{}, ErrDownloadCancelled
 		}
@@ -1225,35 +1249,39 @@ func downloadFromQobuz(req DownloadRequest) (QobuzDownloadResult, error) {
 		GoLog("[Qobuz] Using parallel-fetched cover (%d bytes)\n", len(coverData))
 	}
 
-	if err := EmbedMetadataWithCoverData(outputPath, metadata, coverData); err != nil {
-		fmt.Printf("Warning: failed to embed metadata: %v\n", err)
-	}
-
-	if req.EmbedLyrics && parallelResult != nil && parallelResult.LyricsLRC != "" {
-		lyricsMode := req.LyricsMode
-		if lyricsMode == "" {
-			lyricsMode = "embed"
+	if isSafOutput {
+		GoLog("[Qobuz] SAF output detected - skipping in-backend metadata/lyrics embedding (handled in Flutter)\n")
+	} else {
+		if err := EmbedMetadataWithCoverData(outputPath, metadata, coverData); err != nil {
+			fmt.Printf("Warning: failed to embed metadata: %v\n", err)
 		}
 
-		if !isSafOutput && (lyricsMode == "external" || lyricsMode == "both") {
-			GoLog("[Qobuz] Saving external LRC file...\n")
-			if lrcPath, lrcErr := SaveLRCFile(outputPath, parallelResult.LyricsLRC); lrcErr != nil {
-				GoLog("[Qobuz] Warning: failed to save LRC file: %v\n", lrcErr)
-			} else {
-				GoLog("[Qobuz] LRC file saved: %s\n", lrcPath)
+		if req.EmbedLyrics && parallelResult != nil && parallelResult.LyricsLRC != "" {
+			lyricsMode := req.LyricsMode
+			if lyricsMode == "" {
+				lyricsMode = "embed"
 			}
-		}
 
-		if lyricsMode == "embed" || lyricsMode == "both" {
-			GoLog("[Qobuz] Embedding parallel-fetched lyrics (%d lines)...\n", len(parallelResult.LyricsData.Lines))
-			if embedErr := EmbedLyrics(outputPath, parallelResult.LyricsLRC); embedErr != nil {
-				GoLog("[Qobuz] Warning: failed to embed lyrics: %v\n", embedErr)
-			} else {
-				fmt.Println("[Qobuz] Lyrics embedded successfully")
+			if lyricsMode == "external" || lyricsMode == "both" {
+				GoLog("[Qobuz] Saving external LRC file...\n")
+				if lrcPath, lrcErr := SaveLRCFile(outputPath, parallelResult.LyricsLRC); lrcErr != nil {
+					GoLog("[Qobuz] Warning: failed to save LRC file: %v\n", lrcErr)
+				} else {
+					GoLog("[Qobuz] LRC file saved: %s\n", lrcPath)
+				}
 			}
+
+			if lyricsMode == "embed" || lyricsMode == "both" {
+				GoLog("[Qobuz] Embedding parallel-fetched lyrics (%d lines)...\n", len(parallelResult.LyricsData.Lines))
+				if embedErr := EmbedLyrics(outputPath, parallelResult.LyricsLRC); embedErr != nil {
+					GoLog("[Qobuz] Warning: failed to embed lyrics: %v\n", embedErr)
+				} else {
+					fmt.Println("[Qobuz] Lyrics embedded successfully")
+				}
+			}
+		} else if req.EmbedLyrics {
+			fmt.Println("[Qobuz] No lyrics available from parallel fetch")
 		}
-	} else if req.EmbedLyrics {
-		fmt.Println("[Qobuz] No lyrics available from parallel fetch")
 	}
 
 	if !isSafOutput {

go_backend/qobuz_test.go

@@ -0,0 +1,47 @@
+package gobackend
+
+import "testing"
+
+func TestExtractQobuzDownloadURLFromBody(t *testing.T) {
+	t.Run("reads nested data.url", func(t *testing.T) {
+		body := []byte(`{"success":true,"data":{"url":"https://example.test/audio.flac"}}`)
+
+		got, err := extractQobuzDownloadURLFromBody(body)
+		if err != nil {
+			t.Fatalf("expected no error, got %v", err)
+		}
+		if got != "https://example.test/audio.flac" {
+			t.Fatalf("unexpected URL: %q", got)
+		}
+	})
+
+	t.Run("reads top-level url", func(t *testing.T) {
+		body := []byte(`{"url":"https://example.test/top.flac"}`)
+
+		got, err := extractQobuzDownloadURLFromBody(body)
+		if err != nil {
+			t.Fatalf("expected no error, got %v", err)
+		}
+		if got != "https://example.test/top.flac" {
+			t.Fatalf("unexpected URL: %q", got)
+		}
+	})
+
+	t.Run("returns API error", func(t *testing.T) {
+		body := []byte(`{"error":"track not found"}`)
+
+		_, err := extractQobuzDownloadURLFromBody(body)
+		if err == nil || err.Error() != "track not found" {
+			t.Fatalf("expected track-not-found error, got %v", err)
+		}
+	})
+
+	t.Run("returns message when success false", func(t *testing.T) {
+		body := []byte(`{"success":false,"message":"blocked"}`)
+
+		_, err := extractQobuzDownloadURLFromBody(body)
+		if err == nil || err.Error() != "blocked" {
+			t.Fatalf("expected blocked error, got %v", err)
+		}
+	})
+}

go_backend/tidal.go

@@ -851,7 +851,7 @@ func parseManifest(manifestB64 string) (directURL string, initURL string, mediaU
 	return "", initURL, mediaURLs, nil
 }
 
-func (t *TidalDownloader) DownloadFile(downloadURL, outputPath, itemID string) error {
+func (t *TidalDownloader) DownloadFile(downloadURL, outputPath string, outputFD int, itemID string) error {
 	ctx := context.Background()
 
 	if strings.HasPrefix(downloadURL, "MANIFEST:") {
@@ -864,7 +864,7 @@ func (t *TidalDownloader) DownloadFile(downloadURL, outputPath, itemID string) e
 		if isDownloadCancelled(itemID) {
 			return ErrDownloadCancelled
 		}
-		return t.downloadFromManifest(ctx, strings.TrimPrefix(downloadURL, "MANIFEST:"), outputPath, itemID)
+		return t.downloadFromManifest(ctx, strings.TrimPrefix(downloadURL, "MANIFEST:"), outputPath, outputFD, itemID)
 	}
 
 	if itemID != "" {
@@ -901,7 +901,7 @@ func (t *TidalDownloader) DownloadFile(downloadURL, outputPath, itemID string) e
 		SetItemBytesTotal(itemID, expectedSize)
 	}
 
-	out, err := os.Create(outputPath)
+	out, err := openOutputForWrite(outputPath, outputFD)
 	if err != nil {
 		return err
 	}
@@ -920,30 +920,30 @@ func (t *TidalDownloader) DownloadFile(downloadURL, outputPath, itemID string) e
 	closeErr := out.Close()
 
 	if err != nil {
-		os.Remove(outputPath)
+		cleanupOutputOnError(outputPath, outputFD)
 		if isDownloadCancelled(itemID) {
 			return ErrDownloadCancelled
 		}
 		return fmt.Errorf("download interrupted: %w", err)
 	}
 	if flushErr != nil {
-		os.Remove(outputPath)
+		cleanupOutputOnError(outputPath, outputFD)
 		return fmt.Errorf("failed to flush buffer: %w", flushErr)
 	}
 	if closeErr != nil {
-		os.Remove(outputPath)
+		cleanupOutputOnError(outputPath, outputFD)
 		return fmt.Errorf("failed to close file: %w", closeErr)
 	}
 
 	if expectedSize > 0 && written != expectedSize {
-		os.Remove(outputPath)
+		cleanupOutputOnError(outputPath, outputFD)
 		return fmt.Errorf("incomplete download: expected %d bytes, got %d bytes", expectedSize, written)
 	}
 
 	return nil
 }
 
-func (t *TidalDownloader) downloadFromManifest(ctx context.Context, manifestB64, outputPath, itemID string) error {
+func (t *TidalDownloader) downloadFromManifest(ctx context.Context, manifestB64, outputPath string, outputFD int, itemID string) error {
 	fmt.Println("[Tidal] Parsing manifest...")
 	directURL, initURL, mediaURLs, err := parseManifest(manifestB64)
 	if err != nil {
@@ -988,7 +988,7 @@ func (t *TidalDownloader) downloadFromManifest(ctx context.Context, manifestB64,
 			SetItemBytesTotal(itemID, expectedSize)
 		}
 
-		out, err := os.Create(outputPath)
+		out, err := openOutputForWrite(outputPath, outputFD)
 		if err != nil {
 			return fmt.Errorf("failed to create file: %w", err)
 		}
@@ -1004,19 +1004,19 @@ func (t *TidalDownloader) downloadFromManifest(ctx context.Context, manifestB64,
 		closeErr := out.Close()
 
 		if err != nil {
-			os.Remove(outputPath)
+			cleanupOutputOnError(outputPath, outputFD)
 			if isDownloadCancelled(itemID) {
 				return ErrDownloadCancelled
 			}
 			return fmt.Errorf("download interrupted: %w", err)
 		}
 		if closeErr != nil {
-			os.Remove(outputPath)
+			cleanupOutputOnError(outputPath, outputFD)
 			return fmt.Errorf("failed to close file: %w", closeErr)
 		}
 
 		if expectedSize > 0 && written != expectedSize {
-			os.Remove(outputPath)
+			cleanupOutputOnError(outputPath, outputFD)
 			return fmt.Errorf("incomplete download: expected %d bytes, got %d bytes", expectedSize, written)
 		}
 
@@ -1037,7 +1037,7 @@ func (t *TidalDownloader) downloadFromManifest(ctx context.Context, manifestB64,
 	}
 	GoLog("[Tidal] DASH format - downloading %d segments directly to: %s\n", len(mediaURLs), m4aPath)
 
-	out, err := os.Create(m4aPath)
+	out, err := openOutputForWrite(m4aPath, outputFD)
 	if err != nil {
 		GoLog("[Tidal] Failed to create M4A file: %v\n", err)
 		return fmt.Errorf("failed to create M4A file: %w", err)
@@ -1046,20 +1046,20 @@ func (t *TidalDownloader) downloadFromManifest(ctx context.Context, manifestB64,
 	GoLog("[Tidal] Downloading init segment...\n")
 	if isDownloadCancelled(itemID) {
 		out.Close()
-		os.Remove(m4aPath)
+		cleanupOutputOnError(m4aPath, outputFD)
 		return ErrDownloadCancelled
 	}
 	req, err := http.NewRequestWithContext(ctx, "GET", initURL, nil)
 	if err != nil {
 		out.Close()
-		os.Remove(m4aPath)
+		cleanupOutputOnError(m4aPath, outputFD)
 		GoLog("[Tidal] Init segment request failed: %v\n", err)
 		return fmt.Errorf("failed to create init segment request: %w", err)
 	}
 	resp, err := client.Do(req)
 	if err != nil {
 		out.Close()
-		os.Remove(m4aPath)
+		cleanupOutputOnError(m4aPath, outputFD)
 		if isDownloadCancelled(itemID) {
 			return ErrDownloadCancelled
 		}
@@ -1069,7 +1069,7 @@ func (t *TidalDownloader) downloadFromManifest(ctx context.Context, manifestB64,
 	if resp.StatusCode != 200 {
 		resp.Body.Close()
 		out.Close()
-		os.Remove(m4aPath)
+		cleanupOutputOnError(m4aPath, outputFD)
 		GoLog("[Tidal] Init segment HTTP error: %d\n", resp.StatusCode)
 		return fmt.Errorf("init segment download failed with status %d", resp.StatusCode)
 	}
@@ -1077,7 +1077,7 @@ func (t *TidalDownloader) downloadFromManifest(ctx context.Context, manifestB64,
 	resp.Body.Close()
 	if err != nil {
 		out.Close()
-		os.Remove(m4aPath)
+		cleanupOutputOnError(m4aPath, outputFD)
 		if isDownloadCancelled(itemID) {
 			return ErrDownloadCancelled
 		}
@@ -1089,7 +1089,7 @@ func (t *TidalDownloader) downloadFromManifest(ctx context.Context, manifestB64,
 	for i, mediaURL := range mediaURLs {
 		if isDownloadCancelled(itemID) {
 			out.Close()
-			os.Remove(m4aPath)
+			cleanupOutputOnError(m4aPath, outputFD)
 			return ErrDownloadCancelled
 		}
 
@@ -1105,14 +1105,14 @@ func (t *TidalDownloader) downloadFromManifest(ctx context.Context, manifestB64,
 		req, err := http.NewRequestWithContext(ctx, "GET", mediaURL, nil)
 		if err != nil {
 			out.Close()
-			os.Remove(m4aPath)
+			cleanupOutputOnError(m4aPath, outputFD)
 			GoLog("[Tidal] Segment %d request failed: %v\n", i+1, err)
 			return fmt.Errorf("failed to create segment %d request: %w", i+1, err)
 		}
 		resp, err := client.Do(req)
 		if err != nil {
 			out.Close()
-			os.Remove(m4aPath)
+			cleanupOutputOnError(m4aPath, outputFD)
 			if isDownloadCancelled(itemID) {
 				return ErrDownloadCancelled
 			}
@@ -1122,7 +1122,7 @@ func (t *TidalDownloader) downloadFromManifest(ctx context.Context, manifestB64,
 		if resp.StatusCode != 200 {
 			resp.Body.Close()
 			out.Close()
-			os.Remove(m4aPath)
+			cleanupOutputOnError(m4aPath, outputFD)
 			GoLog("[Tidal] Segment %d HTTP error: %d\n", i+1, resp.StatusCode)
 			return fmt.Errorf("segment %d download failed with status %d", i+1, resp.StatusCode)
 		}
@@ -1130,7 +1130,7 @@ func (t *TidalDownloader) downloadFromManifest(ctx context.Context, manifestB64,
 		resp.Body.Close()
 		if err != nil {
 			out.Close()
-			os.Remove(m4aPath)
+			cleanupOutputOnError(m4aPath, outputFD)
 			if isDownloadCancelled(itemID) {
 				return ErrDownloadCancelled
 			}
@@ -1140,7 +1140,7 @@ func (t *TidalDownloader) downloadFromManifest(ctx context.Context, manifestB64,
 	}
 
 	if err := out.Close(); err != nil {
-		os.Remove(m4aPath)
+		cleanupOutputOnError(m4aPath, outputFD)
 		GoLog("[Tidal] Failed to close M4A file: %v\n", err)
 		return fmt.Errorf("failed to close M4A file: %w", err)
 	}
@@ -1409,7 +1409,7 @@ func isLatinScript(s string) bool {
 func downloadFromTidal(req DownloadRequest) (TidalDownloadResult, error) {
 	downloader := NewTidalDownloader()
 
-	isSafOutput := strings.TrimSpace(req.OutputPath) != ""
+	isSafOutput := isFDOutput(req.OutputFD) || strings.TrimSpace(req.OutputPath) != ""
 	if !isSafOutput {
 		if existingFile, exists := checkISRCExistsInternal(req.OutputDir, req.ISRC); exists {
 			return TidalDownloadResult{FilePath: "EXISTS:" + existingFile}, nil
@@ -1627,6 +1627,9 @@ func downloadFromTidal(req DownloadRequest) (TidalDownloadResult, error) {
 	var m4aPath string
 	if isSafOutput {
 		outputPath = strings.TrimSpace(req.OutputPath)
+		if outputPath == "" && isFDOutput(req.OutputFD) {
+			outputPath = fmt.Sprintf("/proc/self/fd/%d", req.OutputFD)
+		}
 		m4aPath = outputPath
 	} else {
 		if outputExt == ".m4a" || quality == "HIGH" {
@@ -1689,7 +1692,7 @@ func downloadFromTidal(req DownloadRequest) (TidalDownloadResult, error) {
 		return "Direct URL"
 	}())
 
-	if err := downloader.DownloadFile(downloadInfo.URL, outputPath, req.ItemID); err != nil {
+	if err := downloader.DownloadFile(downloadInfo.URL, outputPath, req.OutputFD, req.ItemID); err != nil {
 		if errors.Is(err, ErrDownloadCancelled) {
 			return TidalDownloadResult{}, ErrDownloadCancelled
 		}