Avoid batch remux output collisions

main.go

@@ -1995,9 +1995,10 @@ func (s *appState) addAllConvertToQueue() (int, error) {
 		return 0, fmt.Errorf("no videos loaded")
 	}
 
+	usedOutputs := make(map[string]struct{})
 	count := 0
 	for _, src := range s.loadedVideos {
-		if err := s.addConvertToQueueForSource(src); err != nil {
+		if err := s.addConvertToQueueForSourceWithOutputs(src, usedOutputs); err != nil {
 			return count, fmt.Errorf("failed to add %s: %w", filepath.Base(src.Path), err)
 		}
 		count++
@@ -2006,6 +2007,113 @@ func (s *appState) addAllConvertToQueue() (int, error) {
 	return count, nil
 }
 
+func (s *appState) addConvertToQueueForSourceWithOutputs(src *videoSource, used map[string]struct{}) error {
+	outputBase := s.resolveOutputBase(src, true)
+	cfg := s.convert
+	cfg.OutputBase = outputBase
+
+	outDir := filepath.Dir(src.Path)
+	outName := cfg.OutputFile()
+	if outName == "" {
+		outName = "converted" + cfg.SelectedFormat.Ext
+	}
+	outPath := filepath.Join(outDir, outName)
+	if outPath == src.Path {
+		outPath = filepath.Join(outDir, "converted-"+outName)
+	}
+
+	// Ensure unique output path within batch to avoid overwrites.
+	ext := filepath.Ext(outPath)
+	base := strings.TrimSuffix(outPath, ext)
+	candidate := outPath
+	for i := 2; ; i++ {
+		if _, ok := used[candidate]; !ok {
+			if _, err := os.Stat(candidate); os.IsNotExist(err) {
+				break
+			}
+		}
+		candidate = fmt.Sprintf("%s-%d%s", base, i, ext)
+	}
+	outPath = candidate
+	used[outPath] = struct{}{}
+
+	// Align codec choice with the selected format when the preset implies a codec change.
+	adjustedCodec := s.convert.VideoCodec
+	if preset := s.convert.SelectedFormat.VideoCodec; preset != "" {
+		if friendly := friendlyCodecFromPreset(preset); friendly != "" {
+			if adjustedCodec == "" ||
+				(strings.EqualFold(adjustedCodec, "H.264") && friendly == "H.265") ||
+				(strings.EqualFold(adjustedCodec, "H.265") && friendly == "H.264") {
+				adjustedCodec = friendly
+			}
+		}
+	}
+
+	// Create job config map
+	config := map[string]interface{}{
+		"inputPath":         src.Path,
+		"outputPath":        outPath,
+		"outputBase":        cfg.OutputBase,
+		"selectedFormat":    cfg.SelectedFormat,
+		"quality":           cfg.Quality,
+		"mode":              cfg.Mode,
+		"preserveChapters":  cfg.PreserveChapters,
+		"videoCodec":        adjustedCodec,
+		"encoderPreset":     cfg.EncoderPreset,
+		"crf":               cfg.CRF,
+		"bitrateMode":       cfg.BitrateMode,
+		"bitratePreset":     cfg.BitratePreset,
+		"videoBitrate":      cfg.VideoBitrate,
+		"targetFileSize":    cfg.TargetFileSize,
+		"targetResolution":  cfg.TargetResolution,
+		"frameRate":         cfg.FrameRate,
+		"pixelFormat":       cfg.PixelFormat,
+		"hardwareAccel":     cfg.HardwareAccel,
+		"twoPass":           cfg.TwoPass,
+		"h264Profile":       cfg.H264Profile,
+		"h264Level":         cfg.H264Level,
+		"deinterlace":       cfg.Deinterlace,
+		"deinterlaceMethod": cfg.DeinterlaceMethod,
+		"autoCrop":          cfg.AutoCrop,
+		"cropWidth":         cfg.CropWidth,
+		"cropHeight":        cfg.CropHeight,
+		"cropX":             cfg.CropX,
+		"cropY":             cfg.CropY,
+		"flipHorizontal":    cfg.FlipHorizontal,
+		"flipVertical":      cfg.FlipVertical,
+		"rotation":          cfg.Rotation,
+		"audioCodec":        cfg.AudioCodec,
+		"audioBitrate":      cfg.AudioBitrate,
+		"audioChannels":     cfg.AudioChannels,
+		"audioSampleRate":   cfg.AudioSampleRate,
+		"normalizeAudio":    cfg.NormalizeAudio,
+		"inverseTelecine":   cfg.InverseTelecine,
+		"coverArtPath":      cfg.CoverArtPath,
+		"aspectHandling":    cfg.AspectHandling,
+		"outputAspect":      cfg.OutputAspect,
+		"sourceWidth":       src.Width,
+		"sourceHeight":      src.Height,
+		"sourceDuration":    src.Duration,
+		"sourceBitrate":     src.Bitrate,
+		"fieldOrder":        src.FieldOrder,
+		"autoCompare":       s.autoCompare,
+	}
+
+	job := &queue.Job{
+		Type:        queue.JobTypeConvert,
+		Title:       fmt.Sprintf("Convert %s", filepath.Base(src.Path)),
+		Description: fmt.Sprintf("Output: %s → %s", utils.ShortenMiddle(filepath.Base(src.Path), 40), utils.ShortenMiddle(filepath.Base(outPath), 40)),
+		InputFile:   src.Path,
+		OutputFile:  outPath,
+		Config:      config,
+	}
+
+	s.jobQueue.Add(job)
+	logging.Debug(logging.CatSystem, "added convert job to queue: %s", job.ID)
+
+	return nil
+}
+
 func (s *appState) showBenchmark() {
 	s.stopPreview()
 	s.stopPlayer()