# Plan Updates Summary

## Changes Made

### 1. Added Force Transcode Flag ✅

**Location**: `TDARR_MERGE_PLAN.md` - Phase 2, Section 2.1

Added `--force-transcode` flag to the AV1 advanced features section:

```bash
--force-transcode          # Force transcoding even if file is already in target codec
```

**Status**: 
- ✅ Added to plan
- ⏳ Implementation pending (will be added in Phase 2)
- ✅ Code structure ready (ForceTranscode field exists in AV1AdvancedParams)

### 2. Codec Extensibility Architecture ✅

**New Document**: `CODEC_EXTENSIBILITY.md`

Created comprehensive documentation on how to add future codecs (x264, VP9, etc.):

- **Architecture Pattern**: Each codec follows the same modular pattern
- **Step-by-Step Guide**: How to add a new codec
- **Example Code**: x264 implementation example
- **Integration Points**: How codecs integrate into main pipeline

**Key Points**:
- Each codec gets its own file (e.g., `encoding/x264.go`)
- Codec-specific parameter structs (e.g., `X264AdvancedParams`)
- Shared infrastructure (audio, streams) works for all codecs
- Main pipeline uses codec detection to dispatch

**Updated Files**:
- `TDARR_MERGE_PLAN.md` - Added extensibility notes
- `CODEC_EXTENSIBILITY.md` - New comprehensive guide

### 3. Updated Code Organization ✅

**Location**: `TDARR_MERGE_PLAN.md` - Code Organization section

Updated to show future codec files:
```
encoding/
├── av1.go                # AV1 encoding logic
├── x264.go               # x264 encoding logic (future)
├── vp9.go                # VP9 encoding logic (future)
```

Added extensibility pattern documentation.

### 4. Updated Implementation Priority ✅

**Location**: `TDARR_MERGE_PLAN.md` - Implementation Priority

Added force transcode flag to high priority:
```
5. ⏳ Force transcode flag (`--force-transcode`)
```

### 5. Code Cleanup ✅

**Location**: `main.go`

Removed hardcoded `ForceTranscode = true` and added comment:
```go
// ForceTranscode will be set via CLI flag (--force-transcode) when implemented
// Default: false (skip files already in target codec)
```

## Architecture Benefits

### Modularity
- Each codec is self-contained
- Easy to add new codecs without refactoring

### Consistency
- All codecs follow the same pattern
- Shared infrastructure (audio, streams)

### Future-Proof
- Ready for x264, VP9, HEVC, etc.
- Clear path for implementation

## Next Steps

1. **Implement `--force-transcode` flag** (Phase 2)
   - Add flag parsing in `main.go`
   - Pass to `AV1AdvancedParams`
   - Test with existing AV1 files

2. **Future Codec Implementation** (When needed)
   - Follow pattern in `CODEC_EXTENSIBILITY.md`
   - Create codec-specific file
   - Integrate into main pipeline

## Files Modified

- ✅ `TDARR_MERGE_PLAN.md` - Updated with force transcode flag and extensibility notes
- ✅ `CODEC_EXTENSIBILITY.md` - New comprehensive guide
- ✅ `main.go` - Removed hardcoded force transcode, added comment

## Files Created

- ✅ `CODEC_EXTENSIBILITY.md` - Complete codec extensibility guide