fix: stuff

internal/downloader/downloader.go

@@ -208,29 +208,42 @@ func downloadPlaylist(ctx context.Context, client *http.Client, parsed *url.URL,
 	// Create a client with longer timeout for VOD segments
 	vodClient := &http.Client{Timeout: vodSegmentTimeout}
 
-	// Create temp file for concatenated segments
-	tempTS, err := os.CreateTemp("", "sdl-*.ts")
+	// Create temp directory for segments
+	tempDir, err := os.MkdirTemp("", "sdl-segments-*")
 	if err != nil {
-		return fmt.Errorf("create temp file: %w", err)
+		return fmt.Errorf("create temp directory: %w", err)
 	}
-	tempPath := tempTS.Name()
-	defer os.Remove(tempPath)
+	defer os.RemoveAll(tempDir)
 
 	segments := collectSegments(mediaPlaylist)
 	totalSegments := len(segments)
 	fmt.Fprintf(os.Stderr, "Downloading %d segments...\n", totalSegments)
 
-	// Download and concatenate segments directly
+	// Download each segment to a separate file
+	segmentFiles := make([]string, 0, totalSegments)
 	for i, segment := range segments {
-		if err := downloadSegment(vodCtx, vodClient, finalURL, segment, tempTS); err != nil {
-			tempTS.Close()
+		segmentFile := filepath.Join(tempDir, fmt.Sprintf("segment-%05d.ts", i))
+		file, err := os.Create(segmentFile)
+		if err != nil {
+			return fmt.Errorf("create segment file %d: %w", i, err)
+		}
+
+		if err := downloadSegment(vodCtx, vodClient, finalURL, segment, file); err != nil {
+			file.Close()
 			return fmt.Errorf("download segment %d: %w", i, err)
 		}
-		// Flush after each segment to ensure data is written
-		if err := tempTS.Sync(); err != nil {
-			tempTS.Close()
-			return fmt.Errorf("sync after segment %d: %w", i, err)
+
+		if err := file.Sync(); err != nil {
+			file.Close()
+			return fmt.Errorf("sync segment file %d: %w", i, err)
 		}
+
+		if err := file.Close(); err != nil {
+			return fmt.Errorf("close segment file %d: %w", i, err)
+		}
+
+		segmentFiles = append(segmentFiles, segmentFile)
+
 		// Show progress: segment number, total, and percentage
 		progress := float64(i+1) / float64(totalSegments) * 100
 		fmt.Fprintf(os.Stderr, "\rProgress: %d/%d segments (%.1f%%)", i+1, totalSegments, progress)
@@ -238,23 +251,31 @@ func downloadPlaylist(ctx context.Context, client *http.Client, parsed *url.URL,
 	}
 	fmt.Fprintf(os.Stderr, "\n")
 
-	// Close the file before conversion
-	if err := tempTS.Close(); err != nil {
-		return fmt.Errorf("close temp file: %w", err)
+	// Create concat file for ffmpeg concat protocol (not demuxer)
+	// The concat protocol format is different: just file paths, one per line
+	concatFile := filepath.Join(tempDir, "concat.txt")
+	concatF, err := os.Create(concatFile)
+	if err != nil {
+		return fmt.Errorf("create concat file: %w", err)
 	}
 
-	// Verify the file exists and has content
-	stat, err := os.Stat(tempPath)
+	for _, segFile := range segmentFiles {
+		// Use absolute path for concat protocol
+		absPath, err := filepath.Abs(segFile)
 		if err != nil {
-		return fmt.Errorf("stat temp file: %w", err)
+			concatF.Close()
+			return fmt.Errorf("get absolute path: %w", err)
 		}
-	if stat.Size() == 0 {
-		return fmt.Errorf("downloaded file is empty")
+		// Concat protocol format: just the path, one per line
+		fmt.Fprintf(concatF, "%s\n", absPath)
+	}
+	if err := concatF.Close(); err != nil {
+		return fmt.Errorf("close concat file: %w", err)
 	}
 
 	mp4Name := ensureMP4Extension(name)
-	fmt.Fprintf(os.Stderr, "Converting to MP4 (%.2f MB)...\n", float64(stat.Size())/1024/1024)
-	if err := transmuxToMP4(vodCtx, tempPath, mp4Name); err != nil {
+	fmt.Fprintf(os.Stderr, "Converting to MP4...\n")
+	if err := transmuxToMP4FromConcatProtocol(vodCtx, concatFile, mp4Name); err != nil {
 		return err
 	}
 	fmt.Fprintf(os.Stderr, "Complete: %s\n", mp4Name)
@@ -664,6 +685,99 @@ func inferOutputNameMust(rawURL string) string {
 	return inferOutputName(parsed)
 }
 
+func transmuxToMP4FromConcatProtocol(ctx context.Context, concatFile, mp4Path string) error {
+	if _, err := exec.LookPath("ffmpeg"); err != nil {
+		return errFFmpegMissing
+	}
+
+	if err := os.MkdirAll(filepath.Dir(mp4Path), 0o755); err != nil {
+		return fmt.Errorf("ensure output directory: %w", err)
+	}
+
+	// Use ffmpeg concat protocol (not demuxer) - this is designed for TS files
+	// Format: concat:file1.ts|file2.ts|file3.ts
+	// Or we can use the file list with concat protocol
+	absConcatFile, err := filepath.Abs(concatFile)
+	if err != nil {
+		return fmt.Errorf("get absolute path for concat file: %w", err)
+	}
+
+	// Read the concat file to build the concat protocol string
+	concatContent, err := os.ReadFile(absConcatFile)
+	if err != nil {
+		return fmt.Errorf("read concat file: %w", err)
+	}
+
+	lines := strings.Split(string(concatContent), "\n")
+	var segmentPaths []string
+	for _, line := range lines {
+		line = strings.TrimSpace(line)
+		if line != "" {
+			segmentPaths = append(segmentPaths, line)
+		}
+	}
+
+	if len(segmentPaths) == 0 {
+		return fmt.Errorf("no segments found in concat file")
+	}
+
+	// Build concat protocol string: concat:file1.ts|file2.ts|...
+	concatInput := "concat:" + strings.Join(segmentPaths, "|")
+
+	// Use concat protocol with better flags for TS files
+	cmd := exec.CommandContext(ctx, "ffmpeg",
+		"-y",
+		"-i", concatInput,
+		"-c", "copy",
+		"-movflags", "+faststart",
+		mp4Path)
+	cmd.Stdout = io.Discard
+	var stderr bytes.Buffer
+	cmd.Stderr = &stderr
+
+	if err := cmd.Run(); err != nil {
+		// If copy fails, try with re-encoding
+		msg := strings.TrimSpace(stderr.String())
+		needsReencode := strings.Contains(msg, "could not find corresponding") ||
+			strings.Contains(msg, "error reading header") ||
+			strings.Contains(msg, "Invalid data") ||
+			strings.Contains(msg, "Invalid argument")
+
+		if needsReencode {
+			fmt.Fprintf(os.Stderr, "Copy mode failed, trying re-encode...\n")
+			cmd2 := exec.CommandContext(ctx, "ffmpeg",
+				"-y",
+				"-i", concatInput,
+				"-c:v", "libx264",
+				"-preset", "medium",
+				"-crf", "23",
+				"-c:a", "aac",
+				"-b:a", "128k",
+				"-movflags", "+faststart",
+				mp4Path)
+			cmd2.Stdout = io.Discard
+			var stderr2 bytes.Buffer
+			cmd2.Stderr = &stderr2
+			if err2 := cmd2.Run(); err2 != nil {
+				os.Remove(mp4Path)
+				msg2 := strings.TrimSpace(stderr2.String())
+				if msg2 != "" {
+					return fmt.Errorf("ffmpeg (re-encode): %s", msg2)
+				}
+				return fmt.Errorf("ffmpeg (re-encode): %w", err2)
+			}
+			return nil
+		}
+		os.Remove(mp4Path)
+		if msg != "" {
+			return fmt.Errorf("ffmpeg: %s", msg)
+		}
+		return fmt.Errorf("ffmpeg: %w", err)
+	}
+
+	return nil
+}
+
 func transmuxToMP4FromConcat(ctx context.Context, concatFile, mp4Path string) error {
 	if _, err := exec.LookPath("ffmpeg"); err != nil {
 		return errFFmpegMissing