app.py

import gradio as gr
import whisper
from whisper.utils import write_vtt

from pytube import YouTube
import os
import sys
import subprocess
import re

loaded_model = whisper.load_model("base")
current_size = 'base'

def download_video(link):

    yt = YouTube(link)
    vid = yt.thumbnail_url.split('vi/')[1].split('/')[0]
    print(vid)

    return yt.streams.filter(file_extension='mp4')[0].download(filename=f"{vid}.mp4")

def inference(link):

  yt = YouTube(link)
  vid = yt.thumbnail_url.split('vi/')[1].split('/')[0]

  audio_path = yt.streams.filter(only_audio=True)[0].download(filename= f"{vid}.mp3")
  print(f'audio path :  {audio_path}')
  video_path  = download_video(link)
  
  #video_path = yt.streams.filter(file_extension='mp4')[0].download(filename='video.mp4'
  
  options = dict(beam_size=5, best_of=5, fp16 = False)
  translate_options = dict(task="translate", **options)
  results = loaded_model.transcribe(audio_path,**translate_options)
  
  output_dir = ''
  path = audio_path.split(".")[0]
  
  with open(os.path.join(output_dir, path + ".vtt"), "w") as vtt:
    write_vtt(results["segments"], file=vtt)  

  subtitle = path + ".vtt"
  output_video = path + "_subtitled.mp4"
  
  try:
    os.system(f"ffmpeg -i {video_path} -vf subtitles={subtitle} {output_video}")
  except Exception as exc:
    print(f'system Error : {exc}')
  
  return output_video
  
def change_model(size):
  if size == current_size:
    return

  loaded_model = whisper.load_model(size)
  current_size = size

def populate_metadata(link):
  yt = YouTube(link)
  return yt.thumbnail_url, yt.title

title="Youtube Caption Generator"
description="Generate captions of Youtube videos using OpenAI's Whisper"
block = gr.Blocks()

with block:
    gr.HTML(
        """
            <div style="text-align: center; max-width: 500px; margin: 0 auto;">
              <div>
                <h1>Youtube Caption Generator</h1>
              </div>
              <p style="margin-bottom: 10px; font-size: 94%">
                Generate captions of Youtube videos using OpenAI's Whisper
              </p>
            </div>
        """
    )

    with gr.Group():
        with gr.Box():
          sz = gr.Dropdown(label="Model Size", choices=['base','small', 'medium', 'large'], value='base')
          
          link = gr.Textbox(label="YouTube Link")
          
          with gr.Row().style(mobile_collapse=False, equal_height=True):
            
            input_video  = gr.Video()
            output_video = gr.Video()

          btn = gr.Button("Generate Captions")       
          
          # Events
          btn.click(inference, inputs=[link], outputs=[output_video])
          link.change(download_video,inputs=[link],outputs=[input_video])
          sz.change(change_model, inputs=[sz], outputs=[])

block.launch(debug=True,enable_queue=True)