app.py

import os
import re
import google.generativeai as genai
from moviepy.video.io.VideoFileClip import VideoFileClip
import tempfile
import logging
import gradio as gr
from datetime import timedelta

# Suppress moviepy logs
logging.getLogger("moviepy").setLevel(logging.ERROR)

# Configure Gemini API
genai.configure(api_key=os.environ["GEMINI_API_KEY"])
model = genai.GenerativeModel("gemini-2.0-pro-exp-02-05")

# Supported languages
SUPPORTED_LANGUAGES = [
    "Auto Detect", "English", "Spanish", "French", "German", "Italian",
    "Portuguese", "Russian", "Japanese", "Korean", "Arabic", "Hindi",
    "Chinese", "Dutch", "Turkish", "Polish", "Vietnamese", "Thai"
]

# Magic Prompts
TRANSCRIPTION_PROMPT = """You are a professional subtitling expert. Generate precise subtitles with accurate timestamps following these rules:

1. Use [HH:MM:SS.ms -> HH:MM:SS.ms] format
2. Each subtitle 3-7 words
3. Include speaker changes
4. Preserve emotional tone
5. Format example:

[00:00:05.250 -> 00:00:08.100]
Example subtitle text

Return ONLY subtitles with timestamps."""

TRANSLATION_PROMPT = """Translate these subtitles to {target_language} following:

1. Keep timestamps identical
2. Match text length to timing
3. Preserve technical terms
4. Use natural speech patterns

ORIGINAL:
{subtitles}

TRANSLATED:"""

def parse_timestamp(timestamp_str):
    """Flexible timestamp parser supporting multiple formats"""
    clean_ts = timestamp_str.strip("[] ").replace(',', '.')
    parts = clean_ts.split(':')
    
    seconds = 0.0
    if len(parts) == 3:  # HH:MM:SS.ss
        hours, minutes, seconds_part = parts
        seconds += float(hours) * 3600
    elif len(parts) == 2:  # MM:SS.ss
        minutes, seconds_part = parts
    else:
        raise ValueError(f"Invalid timestamp: {timestamp_str}")
    
    seconds += float(minutes) * 60
    seconds += float(seconds_part)
    return seconds

def create_srt(subtitles_text):
    """Robust SRT converter with error handling"""
    entries = re.split(r'\n{2,}', subtitles_text.strip())
    srt_output = []
    
    for idx, entry in enumerate(entries, 1):
        try:
            # Match various timestamp formats
            time_match = re.search(
                r'\[?\s*((?:\d+:)?\d+:\d+[.,]\d{3})\s*->\s*((?:\d+:)?\d+:\d+[.,]\d{3})\s*\]?',
                entry
            )
            if not time_match:
                continue
                
            start_time = parse_timestamp(time_match.group(1))
            end_time = parse_timestamp(time_match.group(2))
            text = entry.split(']', 1)[-1].strip()
            
            srt_entry = (
                f"{idx}\n"
                f"{timedelta(seconds=start_time)} --> {timedelta(seconds=end_time)}\n"
                f"{text}\n"
            )
            srt_output.append(srt_entry)
            
        except Exception as e:
            print(f"Skipping invalid entry {idx}: {str(e)}")
            continue
    
    return "\n".join(srt_output)

def extract_audio(video_path):
    """High-quality audio extraction"""
    video = VideoFileClip(video_path)
    audio_path = os.path.join(tempfile.gettempdir(), "hq_audio.wav")
    video.audio.write_audiofile(audio_path, fps=44100, nbytes=2, codec='pcm_s16le')
    return audio_path

def gemini_transcribe(audio_path):
    """Audio transcription with Gemini"""
    with open(audio_path, "rb") as f:
        audio_data = f.read()
    
    response = model.generate_content(
        [TRANSCRIPTION_PROMPT, {"mime_type": "audio/wav", "data": audio_data}]
    )
    return response.text

def translate_subtitles(subtitles, target_lang):
    """Context-aware translation"""
    prompt = TRANSLATION_PROMPT.format(
        target_language=target_lang,
        subtitles=subtitles
    )
    response = model.generate_content(prompt)
    return response.text

def process_video(video_path, source_lang, target_lang):
    """Complete processing pipeline"""
    try:
        audio_path = extract_audio(video_path)
        raw_transcription = gemini_transcribe(audio_path)
        srt_original = create_srt(raw_transcription)
        
        original_srt = os.path.join(tempfile.gettempdir(), "original.srt")
        with open(original_srt, "w") as f:
            f.write(srt_original)
        
        translated_srt = None
        if target_lang != "None":
            translated_text = translate_subtitles(srt_original, target_lang)
            translated_srt = os.path.join(tempfile.gettempdir(), "translated.srt")
            with open(translated_srt, "w") as f:
                f.write(create_srt(translated_text))  # Re-parse translated text
        
        os.remove(audio_path)
        return original_srt, translated_srt
    
    except Exception as e:
        print(f"Processing error: {str(e)}")
        return None, None

# Gradio Interface
with gr.Blocks(theme=gr.themes.Soft(), title="AI Subtitle Studio") as app:
    gr.Markdown("# 🎬 Professional Subtitle Generator")
    
    with gr.Row():
        video_input = gr.Video(label="Upload Video", sources=["upload"])
        with gr.Column():
            source_lang = gr.Dropdown(
                label="Source Language",
                choices=SUPPORTED_LANGUAGES,
                value="Auto Detect"
            )
            target_lang = gr.Dropdown(
                label="Translate To",
                choices=["None"] + SUPPORTED_LANGUAGES[1:],
                value="None"
            )
            process_btn = gr.Button("Generate", variant="primary")
    
    with gr.Row():
        original_sub = gr.File(label="Original Subtitles")
        translated_sub = gr.File(label="Translated Subtitles")
    
    process_btn.click(
        process_video,
        inputs=[video_input, source_lang, target_lang],
        outputs=[original_sub, translated_sub]
    )

if __name__ == "__main__":
    app.launch(server_port=7860, share=True)