app.py

import os 
save_dir= os.path.join(os.getcwd(),'docs')
if not os.path.exists(save_dir):
    os.mkdir(save_dir)

transcription_model_id = "openai/whisper-large"
llm_model_id = "tiiuae/falcon-7b-instruct"
HF_TOKEN = os.environ.get("HF_TOKEN", None)

from youtube_transcript_api import YouTubeTranscriptApi
import pytube

# get the transcript from YouTube
def get_yt_transcript(url):
    text = ''
    vid_id = pytube.extract.video_id(url)
    temp = YouTubeTranscriptApi.get_transcript(vid_id)
    for t in temp:
        text+=t['text']+' '
    return text

from pytube import YouTube
import transformers
import torch

# transcribes the video
def transcribe_yt_vid(url):
    # download YouTube video's audio
    yt = YouTube(str(url))
    audio = yt.streams.filter(only_audio = True).first()
    out_file = audio.download(filename="audio.mp3",
                              output_path = save_dir)

    # defining an automatic-speech-recognition pipeline
    asr = transformers.pipeline(
        "automatic-speech-recognition", 
        model=transcription_model_id, 
        device_map= 'auto',
    )

    # setting model config parameters
    asr.model.config.forced_decoder_ids = (
        asr.tokenizer.get_decoder_prompt_ids(
            language="en", 
            task="transcribe"
        )
    )

    # invoking the Whisper model
    temp = asr(out_file,chunk_length_s=20)
    text = temp['text']
    
    # we can do this at the end to release GPU memory
    del(asr)
    torch.cuda.empty_cache()
    
    return text

from pytube import YouTube
from huggingface_hub import InferenceClient

# transcribes the video using the Hugging Face Hub API
def transcribe_yt_vid_api(url,api_token):
    # download YouTube video's audio
    yt = YouTube(str(url))
    audio = yt.streams.filter(only_audio = True).first()
    out_file = audio.download(filename="audio.wav",
                              output_path = save_dir)
    
    # Initialize client for the Whisper model
    client = InferenceClient(model=transcription_model_id, 
                             token=api_token)

    import librosa
    import soundfile as sf

    text = ''
    t=25 # audio chunk length in seconds 
    x, sr = librosa.load(out_file, sr=None)
    # This gives x as audio file in numpy array and sr as original sampling rate
    # The audio needs to be split in 20 second chunks since the API call truncates the response
    for _,i in enumerate(range(0, (len(x)//(t * sr)) +1)):
        y = x[t * sr * i: t * sr *(i+1)]
        split_path = os.path.join(save_dir,"audio_split.wav")
        sf.write(split_path, y, sr)
        text += client.automatic_speech_recognition(split_path)

    return text

def transcribe_youtube_video(url, force_transcribe=False,use_api=False,api_token=None):
    
    yt = YouTube(str(url))
    text = ''
    # get the transcript from YouTube if available
    try:
        text = get_yt_transcript(url)
    except:
        pass
    
    # transcribes the video if YouTube did not provide a transcription 
    # or if you want to force_transcribe anyway
    if text == '' or force_transcribe:
        if use_api:
            text = transcribe_yt_vid_api(url,api_token=api_token)
            transcript_source = 'The transcript was generated using {} via the Hugging Face Hub API.'.format(transcription_model_id)
        else:
            text = transcribe_yt_vid(url)
            transcript_source = 'The transcript was generated using {} hosted locally.'.format(transcription_model_id)
    else:
        transcript_source = 'The transcript was downloaded from YouTube.'
    
    return yt.title, text, transcript_source

def summarize_text(title,text,temperature,words,use_api=False,api_token=None,do_sample=False):
    
    from langchain.chains.llm import LLMChain
    from langchain.prompts import PromptTemplate
    from langchain.chains import ReduceDocumentsChain, MapReduceDocumentsChain
    from langchain.chains.combine_documents.stuff import StuffDocumentsChain
    import torch
    import transformers
    from transformers import BitsAndBytesConfig
    from transformers import AutoTokenizer, AutoModelForCausalLM
    
    from langchain import HuggingFacePipeline
    import torch

    model_kwargs1 = {"temperature":temperature ,
                    "do_sample":do_sample,
                    "min_new_tokens":200-25,
                    "max_new_tokens":200+25,
                    'repetition_penalty':20.0
                    }
    model_kwargs2 = {"temperature":temperature ,
                    "do_sample":do_sample,
                    "min_new_tokens":words, 
                    "max_new_tokens":words+100, 
                    'repetition_penalty':20.0
                    }
    if not do_sample:
        del model_kwargs1["temperature"]
        del model_kwargs2["temperature"]

    if use_api:
        
        from langchain import HuggingFaceHub

        # os.environ["HUGGINGFACEHUB_API_TOKEN"] = api_token
        llm=HuggingFaceHub(
            repo_id=llm_model_id, model_kwargs=model_kwargs1,
            huggingfacehub_api_token=api_token
            )
        llm2=HuggingFaceHub(
            repo_id=llm_model_id, model_kwargs=model_kwargs2,
            huggingfacehub_api_token=api_token
            )
        summary_source = 'The summary was generated using {} via Hugging Face API.'.format(llm_model_id)

    else:
        quantization_config = BitsAndBytesConfig(
            load_in_4bit=True,
            bnb_4bit_compute_dtype=torch.float16,
            bnb_4bit_quant_type="nf4",
            bnb_4bit_use_double_quant=True,
            )

        tokenizer = AutoTokenizer.from_pretrained(llm_model_id)
        model = AutoModelForCausalLM.from_pretrained(llm_model_id,
                                                    # quantization_config=quantization_config
                                                    )
        model.to_bettertransformer()
        
        pipeline = transformers.pipeline(
            "text-generation",
            model=model,
            tokenizer=tokenizer,
            torch_dtype=torch.bfloat16,
            device_map="auto",
            pad_token_id=tokenizer.eos_token_id,
            **model_kwargs1,
        )
        pipeline2 = transformers.pipeline(
            "text-generation",
            model=model,
            tokenizer=tokenizer,
            torch_dtype=torch.bfloat16,
            device_map="auto",
            pad_token_id=tokenizer.eos_token_id,
            **model_kwargs2,
        )
        llm = HuggingFacePipeline(pipeline=pipeline)
        llm2 = HuggingFacePipeline(pipeline=pipeline2)

        summary_source = 'The summary was generated using {} hosted locally.'.format(llm_model_id)


    # Map
    map_template = """
    You are an intelligent AI assistant that is tasked to review the content of a video and provide a concise and accurate summary.\n
    You do not provide information that is not mentioned in the video. You only provide information that you are absolutely sure about.\n
    Summarize the following text in a clear and concise way:\n
    ----------------------- \n
    TITLE: `{title}`\n
    TEXT:\n
    `{docs}`\n
    ----------------------- \n
    BRIEF SUMMARY:\n
    """
    map_prompt = PromptTemplate(
        template = map_template, 
        input_variables = ['title','docs']
        )
    map_chain = LLMChain(llm=llm, prompt=map_prompt)

    # Reduce - Collapse
    collapse_template = """
    You are an intelligent AI assistant that is tasked to review the content of a video and provide a concise and accurate summary.\n
    You do not provide information that is not mentioned in the video. You only provide information that you are absolutely sure about.\n
    The following is set of partial summaries of a video:\n
    ----------------------- \n
    TITLE: `{title}`\n
    PARTIAL SUMMARIES:\n
    `{doc_summaries}`\n 
    ----------------------- \n
    Take these and distill them into a consolidated summary.\n
    SUMMARY:\n
    """

    collapse_prompt = PromptTemplate(
        template = collapse_template, 
        input_variables = ['title','doc_summaries']
        )
    collapse_chain = LLMChain(llm=llm, prompt=collapse_prompt)

    # Takes a list of documents, combines them into a single string, and passes this to an LLMChain
    collapse_documents_chain = StuffDocumentsChain(
        llm_chain=collapse_chain, document_variable_name="doc_summaries"
        )

    # Final Reduce - Combine
    combine_template = """\n
    You are an intelligent AI assistant that is tasked to review the content of a video and provide a concise and accurate summary.\n
    You do not provide information that is not mentioned in the video. You only provide information that you are absolutely sure about.\n
    The following is a set of partial summaries of a video:\n
    ----------------------- \n
    TITLE: `{title}`\n
    PARTIAL SUMMARIES:\n
    `{doc_summaries}`\n 
    ----------------------- \n
    Generate an executive summary of the whole text in maximum {words} words that contains the main messages, points, and arguments presented in the video as bullet points. Avoid duplications or redundant information. \n
    EXECUTIVE SUMMARY:\n
    """
    combine_prompt = PromptTemplate(
        template = combine_template, 
        input_variables = ['title','doc_summaries','words']
        )
    combine_chain = LLMChain(llm=llm2, prompt=combine_prompt)

    # Takes a list of documents, combines them into a single string, and passes this to an LLMChain
    combine_documents_chain = StuffDocumentsChain(
        llm_chain=combine_chain, document_variable_name="doc_summaries"
        )

    # Combines and iteratively reduces the mapped documents
    reduce_documents_chain = ReduceDocumentsChain(
        # This is final chain that is called.
        combine_documents_chain=combine_documents_chain,
        # If documents exceed context for `StuffDocumentsChain`
        collapse_documents_chain=collapse_documents_chain,
        # The maximum number of tokens to group documents into.
        token_max=800,
        )

    # Combining documents by mapping a chain over them, then combining results
    map_reduce_chain = MapReduceDocumentsChain(
        # Map chain
        llm_chain=map_chain,
        # Reduce chain
        reduce_documents_chain=reduce_documents_chain,
        # The variable name in the llm_chain to put the documents in
        document_variable_name="docs",
        # Return the results of the map steps in the output
        return_intermediate_steps=False,
        )

    from langchain.document_loaders import TextLoader
    from langchain.text_splitter import TokenTextSplitter
    
    with open(save_dir+'/transcript.txt','w') as f:
        f.write(text)
    loader = TextLoader(save_dir+"/transcript.txt")
    doc = loader.load()
    text_splitter = TokenTextSplitter(chunk_size=800, chunk_overlap=100)
    docs = text_splitter.split_documents(doc)

    summary = map_reduce_chain.run({'input_documents':docs, 'title':title, 'words':words})

    try:
        del(map_reduce_chain,reduce_documents_chain,combine_chain,collapse_documents_chain,map_chain,collapse_chain,llm,llm2,pipeline,pipeline2,model,tokenizer)
    except:
        pass
    torch.cuda.empty_cache()

    return summary, summary_source

import gradio as gr 
import pytube
from pytube import YouTube

def get_youtube_title(url):
    yt = YouTube(str(url))
    return yt.title

def get_video(url):
    vid_id = pytube.extract.video_id(url)
    embed_html = '<iframe width="100%" height="315" src="https://www.youtube.com/embed/{}" title="YouTube video player" frameborder="0" allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture" allowfullscreen></iframe>'.format(vid_id)
    return embed_html

def summarize_youtube_video(url,force_transcribe,api_token="",
                            temperature=1.0,words=150,do_sample=True):
    print("URL:",url)
    if api_token == "":
        api_token = HF_TOKEN
    title,text,transcript_source = transcribe_youtube_video(url,force_transcribe,True,api_token)
    print("Transcript:",text[:500])
    summary, summary_source = summarize_text(title,text,temperature,words,True,api_token,do_sample)
    print("Summary:",summary)
    return summary, text, transcript_source, summary_source

html = '<iframe width="100%" height="315" src="https://www.youtube.com/embed/" title="YouTube video player" frameborder="0" allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture" allowfullscreen></iframe>'

# def change_transcribe_api(vis):
#     return gr.Checkbox(value=False, visible=vis)

# def change_api_token(vis):
#     return gr.Textbox(visible=vis)

def update_source(source):
    return gr.Textbox(info=source)

def show_temp(vis):
    return gr.Slider(visible=vis)

# Defining the structure of the UI
with gr.Blocks() as demo:
    with gr.Row():
        gr.Markdown("# Summarize a YouTube Video")
    
    with gr.Row():
        with gr.Column(scale=4):
            url = gr.Textbox(label="Enter YouTube video URL here:",placeholder="https://www.youtube.com/watch?v=",info="The video must not be age-restricted. Otherwise, the transcription will fail. The demo supports videos in English language only.")
        with gr.Column(scale=1):
            api_token = gr.Textbox(label="Paste your Hugging Face API token here (Optional):",placeholder="hf_...",visible=True,show_label=True,info='The API token passed via this field is not stored. It is only passed through the Hugging Face Hub API for inference.')
        with gr.Column(scale=1):
            sum_btn = gr.Button("Summarize!")
            gr.Markdown("Please like the repo if you find this helpful. Detailed instructions for recreating this tool are provided [here](https://pub.towardsai.net/a-complete-guide-for-creating-an-ai-assistant-for-summarizing-youtube-videos-part-1-32fbadabc2cc?sk=34269402931178039c4c3589df4a6ec5) and [here](https://pub.towardsai.net/a-complete-guide-for-creating-an-ai-assistant-for-summarizing-youtube-videos-part-2-a008ee18f341?sk=d59046b36a52c74dfa8befa99183e5b6).")


    with gr.Accordion("Transcription Settings",open=False):
        with gr.Row():
            force_transcribe = gr.Checkbox(label="Transcribe even if transcription is available.", info='If unchecked, the app attempts to download the transcript from YouTube first. Check this if the transcript does not seem accurate.')
            # use_transcribe_api = gr.Checkbox(label="Transcribe using the HuggingFaceHub API.",visible=False)
        
    with gr.Accordion("Summarization Settings",open=False):
        with gr.Row():
            # use_llm_api = gr.Checkbox(label="Summarize using the HuggingFaceHub API.",visible=True)
            do_sample = gr.Checkbox(label="Set the Temperature",value=False,visible=True)
            temperature = gr.Slider(minimum=0.01,maximum=1.0,value=0.25,label="Generation temperature",visible=False)
            words = gr.Slider(minimum=100,maximum=500,value=200,label="Length of the summary")
            
    gr.Markdown("# Results")

    title = gr.Textbox(label="Video Title",placeholder="title...")
    
    with gr.Row():
        video = gr.HTML(html,scale=1)
        summary_source = gr.Textbox(visible=False,scale=0)
        summary = gr.Textbox(label="Summary",placeholder="summary...",scale=1)
    
    with gr.Row():
        with gr.Group():
            transcript = gr.Textbox(label="Full Transcript",placeholder="transcript...",show_label=True)
            transcript_source = gr.Textbox(visible=False)

    with gr.Accordion("Notes",open=False):
        gr.Markdown("""
                    1. This app attempts to download the transcript from Youtube first. If the transcript is not available, or the prompts require, the video will be transcribed.\n
                    2. The app performs best on videos in which the number of speakers is limited or when the YouTube transcript includes annotations of the speakers.\n 
                    3. The trascription does not annotate the speakers which may downgrade the quality of the summary if there are more than one speaker.\n
                    """)
    
    # Defining the interactivity of the UI elements
    # force_transcribe.change(fn=change_transcribe_api,inputs=force_transcribe,outputs=use_transcribe_api)
    # use_transcribe_api.change(fn=change_api_token,inputs=use_transcribe_api,outputs=api_token)    
    # use_llm_api.change(fn=change_api_token,inputs=use_llm_api,outputs=api_token)
    transcript_source.change(fn=update_source,inputs=transcript_source,outputs=transcript)
    summary_source.change(fn=update_source,inputs=summary_source,outputs=summary)
    do_sample.change(fn=show_temp,inputs=do_sample,outputs=temperature)
    
    # Defining the functions to call on clicking the button
    sum_btn.click(fn=get_youtube_title, inputs=url, outputs=title, api_name="get_youtube_title", queue=False)
    sum_btn.click(fn=summarize_youtube_video, inputs=[url,force_transcribe,api_token,temperature,words,do_sample], 
                  outputs=[summary,transcript, transcript_source, summary_source], api_name="summarize_youtube_video", queue=True)
    sum_btn.click(fn=get_video, inputs=url, outputs=video, api_name="get_youtube_video", queue=False)

demo.queue()
demo.launch(share=False)