Files
LocalAI/backend/python/nemo/backend.py
Ettore Di Giacinto ec7e5129e7 feat(nemo): add Nemo (only asr for now) backend
Signed-off-by: Ettore Di Giacinto <mudler@localai.io>
2026-02-07 00:00:20 +01:00

148 lines
4.7 KiB
Python

#!/usr/bin/env python3
"""
gRPC server of LocalAI for NVIDIA NEMO Toolkit ASR.
"""
from concurrent import futures
import time
import argparse
import signal
import sys
import os
import backend_pb2
import backend_pb2_grpc
import torch
import nemo.collections.asr as nemo_asr
import grpc
def is_float(s):
try:
float(s)
return True
except ValueError:
return False
def is_int(s):
try:
int(s)
return True
except ValueError:
return False
_ONE_DAY_IN_SECONDS = 60 * 60 * 24
MAX_WORKERS = int(os.environ.get('PYTHON_GRPC_MAX_WORKERS', '1'))
class BackendServicer(backend_pb2_grpc.BackendServicer):
def Health(self, request, context):
return backend_pb2.Reply(message=bytes("OK", 'utf-8'))
def LoadModel(self, request, context):
if torch.cuda.is_available():
device = "cuda"
else:
device = "cpu"
mps_available = hasattr(torch.backends, "mps") and torch.backends.mps.is_available()
if mps_available:
device = "mps"
if not torch.cuda.is_available() and request.CUDA:
return backend_pb2.Result(success=False, message="CUDA is not available")
self.device = device
self.options = {}
for opt in request.Options:
if ":" not in opt:
continue
key, value = opt.split(":", 1)
if is_float(value):
value = float(value)
elif is_int(value):
value = int(value)
elif value.lower() in ["true", "false"]:
value = value.lower() == "true"
self.options[key] = value
model_name = request.Model or "nvidia/parakeet-tdt-0.6b-v3"
try:
print(f"Loading NEMO ASR model from {model_name}", file=sys.stderr)
self.model = nemo_asr.models.ASRModel.from_pretrained(model_name=model_name)
print("NEMO ASR model loaded successfully", file=sys.stderr)
except Exception as err:
print(f"[ERROR] LoadModel failed: {err}", file=sys.stderr)
import traceback
traceback.print_exc(file=sys.stderr)
return backend_pb2.Result(success=False, message=str(err))
return backend_pb2.Result(message="Model loaded successfully", success=True)
def AudioTranscription(self, request, context):
result_segments = []
text = ""
try:
audio_path = request.dst
if not audio_path or not os.path.exists(audio_path):
print(f"Error: Audio file not found: {audio_path}", file=sys.stderr)
return backend_pb2.TranscriptResult(segments=[], text="")
# NEMO's transcribe method accepts a list of audio paths and returns a list of transcripts
results = self.model.transcribe([audio_path])
if not results or len(results) == 0:
return backend_pb2.TranscriptResult(segments=[], text="")
# Get the transcript text from the first result
text = results[0]
if text:
# Create a single segment with the full transcription
result_segments.append(backend_pb2.TranscriptSegment(
id=0, start=0, end=0, text=text
))
except Exception as err:
print(f"Error in AudioTranscription: {err}", file=sys.stderr)
import traceback
traceback.print_exc(file=sys.stderr)
return backend_pb2.TranscriptResult(segments=[], text="")
return backend_pb2.TranscriptResult(segments=result_segments, text=text)
def serve(address):
server = grpc.server(
futures.ThreadPoolExecutor(max_workers=MAX_WORKERS),
options=[
('grpc.max_message_length', 50 * 1024 * 1024),
('grpc.max_send_message_length', 50 * 1024 * 1024),
('grpc.max_receive_message_length', 50 * 1024 * 1024),
])
backend_pb2_grpc.add_BackendServicer_to_server(BackendServicer(), server)
server.add_insecure_port(address)
server.start()
print("Server started. Listening on: " + address, file=sys.stderr)
def signal_handler(sig, frame):
print("Received termination signal. Shutting down...")
server.stop(0)
sys.exit(0)
signal.signal(signal.SIGINT, signal_handler)
signal.signal(signal.SIGTERM, signal_handler)
try:
while True:
time.sleep(_ONE_DAY_IN_SECONDS)
except KeyboardInterrupt:
server.stop(0)
if __name__ == "__main__":
parser = argparse.ArgumentParser(description="Run the gRPC server.")
parser.add_argument("--addr", default="localhost:50051", help="The address to bind the server to.")
args = parser.parse_args()
serve(args.addr)