Files
2026-07-13 13:30:30 +08:00

113 lines
3.9 KiB
Python

# Copyright 2025 Google LLC
#
# 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
#
# https://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.
import asyncio
import audioop
import base64
import json
import logging
import numpy as np
logger = logging.getLogger(__name__)
async def handle_twilio_to_gemini(
websocket, audio_queue: asyncio.Queue, resampler, call_state
):
"""Handles the inbound audio stream from Twilio to the Gemini API."""
async for message_str in websocket.iter_text():
try:
await asyncio.sleep(0) # Yield control to event loop
msg = json.loads(message_str)
if msg["event"] == "media":
if not call_state.get("active"):
continue
# 1. Decode Base64
chunk_ulaw = base64.b64decode(msg["media"]["payload"])
# 2. Decode u-law -> PCM
chunk_pcm = audioop.ulaw2lin(chunk_ulaw, 2)
# 3. PCM -> Float32
arr_8k = np.frombuffer(chunk_pcm, dtype=np.int16)
arr_8k_float = arr_8k.astype(np.float32) / 32768.0
# 4. Resample 8k -> 16k
arr_16k_float = resampler.process(
arr_8k_float, ratio=2.0, end_of_input=False
)
# 5. Float32 -> Int16
arr_16k = (arr_16k_float * 32767).astype(np.int16)
await audio_queue.put(arr_16k.tobytes())
elif msg["event"] == "start":
call_state["stream_sid"] = msg["start"]["streamSid"]
call_state["active"] = True
logger.info(f"Stream started: {msg['start']['streamSid']}")
elif msg["event"] == "stop":
call_state["active"] = False
break
except Exception as e:
logger.error(f"Inbound error: {e}")
break
async def handle_gemini_to_twilio(
websocket, audio_queue: asyncio.Queue, resampler, call_state
):
"""Handles the outbound audio stream from the Gemini API to Twilio."""
logger.info("--- RUNNING LATEST VERSION OF gemini_to_twilio ---")
while True:
await asyncio.sleep(0)
try:
# Receive 24k PCM bytes from Gemini
chunk_24k_bytes = await asyncio.wait_for(audio_queue.get(), timeout=1.0)
if chunk_24k_bytes:
# 1. Bytes -> Float32
arr_24k = np.frombuffer(chunk_24k_bytes, dtype=np.int16)
arr_24k_float = arr_24k.astype(np.float32) / 32768.0
# 2. Resample 24k -> 8k
arr_8k_float = resampler.process(
arr_24k_float, ratio=(8000 / 24000), end_of_input=False
)
# 3. Float32 -> Int16
arr_8k = (arr_8k_float * 32767).astype(np.int16)
# 4. PCM -> u-law
chunk_ulaw = audioop.lin2ulaw(arr_8k.tobytes(), 2)
# 5. Send
payload = base64.b64encode(chunk_ulaw).decode("utf-8")
if sid := call_state.get("stream_sid"):
await websocket.send_json(
{
"event": "media",
"streamSid": sid,
"media": {"payload": payload},
}
)
except asyncio.TimeoutError:
if not call_state.get("active", True):
break
except Exception as e:
logger.error(f"Outbound error: {e}")
continue