Add Resemble AI as a new TTS provider plugin (#1631)

Co-authored-by: Zohaib Ahmed <zohaib@resemble.ai>

Author: plangary

livekit-plugins/livekit-plugins-resemble/README.md

@@ -0,0 +1,118 @@
+# LiveKit Plugins Resemble
+
+Agent Framework plugin for voice synthesis with the [Resemble AI](https://www.resemble.ai/) API, using both their REST API and WebSocket streaming interface.
+
+## Installation
+
+```bash
+pip install livekit-plugins-resemble
+```
+
+## Pre-requisites
+
+You'll need an API key from Resemble AI. It can be set as an environment variable: `RESEMBLE_API_KEY`
+
+Additionally, you'll need the voice UUID from your Resemble AI account.
+
+## Examples
+
+### Recommended
+
+```python
+import asyncio
+from livekit.plugins.resemble import TTS
+
+async def run_tts_example():
+    # Use TTS with async context manager for automatic resource cleanup
+    async with TTS(
+        api_key="your_api_key",  # or set RESEMBLE_API_KEY environment variable
+        voice_uuid="your_voice_uuid",
+        # Optional parameters
+        sample_rate=44100,  # Sample rate in Hz (default: 44100)
+        precision="PCM_16",  # Audio precision (PCM_32, PCM_24, PCM_16, MULAW)
+        output_format="wav",  # Output format (wav or mp3)
+    ) as tts:
+        # One-off synthesis (uses REST API)
+        audio_stream = tts.synthesize("Hello, world!")
+        
+        # Process chunks as they arrive
+        async for chunk in audio_stream:
+            # Audio data is in the 'frame.data' attribute of SynthesizedAudio objects
+            audio_data = chunk.frame.data
+            print(f"Received chunk: {len(audio_data)} bytes")
+        
+        # Alternative: collect all audio at once into a single AudioFrame
+        audio_stream = tts.synthesize("Another example sentence.")
+        audio_frame = await audio_stream.collect()
+        print(f"Collected complete audio: {len(audio_frame.data)} bytes")
+        
+        # Real-time streaming synthesis (uses WebSocket API)
+        # Only available for Business plan users in Resemble AI
+        stream = tts.stream()
+        await stream.synthesize_text("Hello, world!")
+        
+
+
+# Run the example
+asyncio.run(run_tts_example())
+```
+
+### Alternative: Manual Resource Management
+
+If you prefer to manage resources manually, make sure to properly clean up:
+
+```python
+import asyncio
+from livekit.plugins.resemble import TTS
+
+async def run_tts_example():
+    # Initialize TTS with your credentials
+    tts = TTS(
+        api_key="your_api_key", 
+        voice_uuid="your_voice_uuid",
+    )
+
+    try:
+        # TTS operations
+        audio_stream = tts.synthesize("Hello, world!")
+        async for chunk in audio_stream:
+            # Access audio data correctly
+            process_audio(chunk.frame.data)
+    finally:
+        # Always clean up resources when done
+        await tts.aclose()
+
+# Run the example
+asyncio.run(run_tts_example())
+```
+
+### Resource Management
+
+When using this plugin outside of the LiveKit agent framework, it's important to properly manage the TTS instance lifecycle:
+
+1. **Preferred method**: Use the async context manager pattern (`async with TTS(...) as tts:`)
+2. If managing manually, always call `await tts.aclose()` in a finally block
+3. If you prefer to provide your own HTTP session, you can pass it using the `http_session` parameter:
+
+```python
+import aiohttp
+
+async def with_custom_session():
+    async with aiohttp.ClientSession() as session:
+        async with TTS(
+            api_key="your_api_key",
+            voice_uuid="your_voice_uuid",
+            http_session=session
+        ) as tts:
+            # Use TTS...
+            # No need to manually close anything - context managers handle it all
+```
+
+## Implementation Details
+
+This plugin uses two different approaches to generate speech:
+
+1. **One-off Synthesis** - Uses Resemble's REST API for simple text-to-speech conversion
+2. **Streaming Synthesis** - Uses Resemble's WebSocket API for real-time streaming synthesis
+
+The WebSocket streaming API is only available for Resemble AI Business plan users. 

livekit-plugins/livekit-plugins-resemble/livekit/plugins/resemble/__init__.py

@@ -0,0 +1,37 @@
+# Copyright 2023 LiveKit, Inc.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+from .tts import TTS, ChunkedStream, SynthesizeStream
+from .version import __version__
+
+__all__ = ["TTS", "ChunkedStream", "SynthesizeStream", "__version__"]
+
+from livekit.agents import Plugin
+
+
+class ResemblePlugin(Plugin):
+    def __init__(self) -> None:
+        super().__init__(__name__, __version__, __package__)
+
+
+Plugin.register_plugin(ResemblePlugin())
+
+# Cleanup docs of unexported modules
+_module = dir()
+NOT_IN_ALL = [m for m in _module if m not in __all__]
+
+__pdoc__ = {}
+
+for n in NOT_IN_ALL:
+    __pdoc__[n] = False 

livekit-plugins/livekit-plugins-resemble/livekit/plugins/resemble/log.py

@@ -0,0 +1,3 @@
+import logging
+
+logger = logging.getLogger("livekit.plugins.resemble") 

livekit-plugins/livekit-plugins-resemble/livekit/plugins/resemble/models.py

@@ -0,0 +1,10 @@
+from enum import Enum
+
+
+class OutputFormat(str, Enum):
+    WAV = "wav"
+    MP3 = "mp3"
+
+
+class Precision(str, Enum):
+    PCM_16 = "PCM_16"

livekit-plugins/livekit-plugins-resemble/livekit/plugins/resemble/py.typed

@@ -0,0 +1,3 @@
+
+
+