Files
Brancheneinstufung2/transcription-tool/backend/services/transcription_service.py
2026-02-18 09:12:04 +00:00

95 lines
3.3 KiB
Python

import os
import time
import logging
from google import genai
from google.genai import types
from ..config import settings
logger = logging.getLogger(__name__)
class TranscriptionService:
def __init__(self):
if not settings.GEMINI_API_KEY:
raise Exception("Gemini API Key missing.")
self.client = genai.Client(api_key=settings.GEMINI_API_KEY)
def transcribe_chunk(self, file_path: str, offset_seconds: int = 0) -> dict:
"""
Uploads a chunk to Gemini and returns the transcription with timestamps.
"""
logger.info(f"Uploading chunk {file_path} to Gemini...")
# 1. Upload file (positional argument)
media_file = self.client.files.upload(file=file_path)
# 2. Wait for processing (usually fast for audio)
while media_file.state == "PROCESSING":
time.sleep(2)
media_file = self.client.files.get(name=media_file.name)
if media_file.state == "FAILED":
raise Exception("File processing failed at Gemini.")
# 3. Transcribe with Diarization and Timestamps (Plain Text Mode for Stability)
prompt = """
Transkribiere dieses Audio wortgetreu.
Identifiziere die Sprecher (Speaker A, Speaker B, etc.).
Gib das Ergebnis EXAKT in diesem Format zurück (pro Zeile ein Sprecherwechsel):
[MM:SS] Speaker Name: Gesprochener Text...
Beispiel:
[00:00] Speaker A: Hallo zusammen.
[00:05] Speaker B: Guten Morgen.
"""
logger.info(f"Generating transcription for {file_path}...")
response = self.client.models.generate_content(
model="gemini-2.0-flash",
contents=[media_file, prompt],
config=types.GenerateContentConfig(
temperature=0.1,
max_output_tokens=8192
)
)
# Cleanup: Delete file from Gemini storage
self.client.files.delete(name=media_file.name)
# Parse Plain Text to JSON
structured_data = self.parse_transcript(response.text)
import json
return {
"raw_text": json.dumps(structured_data), # Return valid JSON string
"offset": offset_seconds
}
def parse_transcript(self, text: str) -> list:
"""
Parses lines like '[00:12] Speaker A: Hello world' into structured JSON.
"""
import re
results = []
# Regex to match: [MM:SS] Speaker: Text
# Flexible for MM:SS or H:MM:SS
pattern = re.compile(r"^\[(\d{1,2}:\d{2}(?::\d{2})?)\]\s*([^:]+):\s*(.+)$")
for line in text.strip().split('\n'):
line = line.strip()
if not line: continue
match = pattern.match(line)
if match:
time_str, speaker, content = match.groups()
results.append({
"time": time_str,
"speaker": speaker.strip(),
"text": content.strip()
})
else:
# Fallback: Append to previous if it looks like continuation
if results and not line.startswith("["):
results[-1]["text"] += " " + line
return results