fetchYoutubeSubtitle.py

import json
import os
import requests


from langchain.text_splitter import RecursiveCharacterTextSplitter, TokenTextSplitter
from typing import List, Dict

SUBTITLE_DOWNLOADER_URL = 'https://savesubs.com'

def fetchYoutubeSubtitleUrls(video_id):
    headers = {
        'accept': 'application/json, text/plain, */*',
        'accept-language': 'en-US,en;q=0.9,zh-CN;q=0.8,zh;q=0.7',
        'cache-control': 'no-cache',
        'Content-Type': 'application/json; charset=UTF-8',
        'pragma': 'no-cache',
        'User-Agent': 'Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/111.0.0.0 Safari/537.36',
        'x-auth-token': os.environ.get('SAVESUBS_X_AUTH_TOKEN', ''),
        'x-requested-domain': 'savesubs.com',
        'X-requested-with': 'xmlhttprequest',
        'sec-ch-ua': '"Google Chrome";v="111", "Not(A:Brand";v="8", "Chromium";v="111"',
        'sec-ch-ua-mobile': '?0',
        'sec-ch-ua-platform': 'Linux',
        'sec-fetch-dest': 'empty',
        'sec-fetch-mode': 'cors',
        'sec-fetch-site': 'same-origin',
        'authority': 'savesubs.com',
        'origin': 'https://savesubs.com',
        'referer': f'https://savesubs.com/process?url=https%3A%2F%2Fwww.youtube.com%2Fwatch%3Fv%3D{video_id}'
    }
    data = {
        'data': {'url': f'https://www.youtube.com/watch?v={video_id}'}
    }
    session = requests.Session()

    proxy = os.environ.get('PROXY', None)
    if proxy:
        session.proxies = {
            "http": proxy,
            "https": proxy,
        }

    response = session.post(SUBTITLE_DOWNLOADER_URL + '/action/extract', json=data, headers=headers)
    if not response.ok:
        logger.error(headers, "request header")
        logger.error(response.headers.raw())
        return {'title': None, 'subtitleList': None, 'error': response.statusText}
    else:
        try:
            json = response.json().get('response', {})
            logger.info(json, 'subtitle url')
            return {'title': json.get('title'), 'subtitleList': json.get('formats')}
        except Exception as error:
            logger.error(error)
            return {'title': None, 'subtitleList': None, 'error': str(error)}


async def find(subtitleList: List[Dict], args: Dict) -> Dict:
    key = list(args.keys())[0]
    return next((item for item in subtitleList if item[key] == args[key]), None)

async def fetchYoutubeSubtitle(videoId: str) -> Dict:
    subtitle_url = ""
    betterSubtitle = {}
    subtitleList = []
    title = ""
    error = ""

    result = await fetchYoutubeSubtitleUrls(videoId)
    title, subtitleList, error = result["title"], result["subtitleList"], result["error"]

    if not subtitleList or len(subtitleList) <= 0:
        return {"title": title, "docs": None, "error": error}

    betterSubtitle = (
        await find(subtitleList, {"quality": "English"})
        or await find(subtitleList, {"quality": "English (auto"})
        or await find(subtitleList, {"quality": "zh-CN"})
        or subtitleList[0]
    )

    subtitleUrl = f"{SUBTITLE_DOWNLOADER_URL}{betterSubtitle['url']}?ext=srt"

    session = requests.Session()

    proxy = os.environ.get('PROXY', None)
    if proxy:
        session.proxies = {
            "http": proxy,
            "https": proxy,
        }
    response = session.get(url)

    loader = SRTLoader(await response.blob())
    splitter = TokenTextSplitter(
        encodingName="cl100k_base",
        chunkSize=2048,
    )

    docs = await loader.loadAndSplit(splitter)
    return {"title": title, "docs": docs}