feat: rate based sync

README.md

@@ -7,9 +7,11 @@ A Python video player using VLC SDK with synchan server timecode synchronization
 - VLC-based video playback with full media support
 - Real-time synchronization with synchan server
 - Reactive programming with RxPY
-- Automatic timecode correction
+- **Advanced synchronization with latency compensation**
+- **Playback rate adjustment for smooth sync**
+- Automatic timecode correction with smart seeking
 - Playback state synchronization
-- Volume and fullscreen controls
+- Volume, playback rate, and fullscreen controls
 
 ## Installation
 
@@ -110,8 +112,11 @@ poetry run python -m vlchan.player video.mp4 http://192.168.1.100:3000
 - `get_volume() -> int`: Get current volume
 - `set_fullscreen(fullscreen: bool)`: Toggle fullscreen
 - `get_position() -> float`: Get current position in seconds
+- `get_compensated_position(latency: float) -> float`: Get latency-compensated position
 - `get_duration() -> float`: Get video duration in seconds
 - `is_playing() -> bool`: Check if playing
+- `get_rate() -> float`: Get current playback rate
+- `set_rate(rate: float)`: Set playback rate (1.0 = normal speed)
 - `cleanup()`: Clean up resources
 
 #### Properties
@@ -128,12 +133,32 @@ Data class containing synchronization state:
 
 ## Synchronization
 
-The player automatically synchronizes with the synchan server:
+The player uses advanced synchronization logic similar to the synchan VideoPlayer component:
 
-1. **Playback State**: Play/pause commands are synchronized
-2. **Time Position**: Video seeks to match synchan timecode
-3. **Threshold**: Only seeks if time difference exceeds 100ms
-4. **Reconnection**: Automatically attempts to reconnect on connection loss
+1. **Latency Compensation**: Server time is adjusted by network latency
+2. **Smart Seeking**: Large time differences (>1s) trigger immediate seeking
+3. **Playback Rate Adjustment**: Small differences are corrected by adjusting playback speed
+4. **Rate Formula**: `rate = 1 + min(max(diff * 0.5, -0.05), 0.05)`
+5. **Playback State**: Play/pause commands are synchronized
+6. **Reconnection**: Automatically attempts to reconnect on connection loss
+
+### Synchronization Algorithm
+
+```python
+# Apply latency compensation
+compensated_time = server_time + latency / 1000
+
+# Calculate difference
+diff = compensated_time - local_time
+
+# Large difference: seek immediately
+if diff > 1.0:
+    player.seek(compensated_time)
+
+# Small difference: adjust playback rate
+rate = 1 + min(max(diff * 0.5, -0.05), 0.05)
+player.set_rate(rate)
+```
 
 ## Requirements