Files
ALwrity/backend/services/story_writer/audio_generation_service.py

378 lines
15 KiB
Python

"""
Audio Generation Service for Story Writer
Generates audio narration for story scenes using TTS (Text-to-Speech) providers.
"""
import os
import uuid
from typing import List, Dict, Any, Optional
from pathlib import Path
from loguru import logger
from fastapi import HTTPException
class StoryAudioGenerationService:
"""Service for generating audio narration for story scenes."""
def __init__(self, output_dir: Optional[str] = None):
"""
Initialize the audio generation service.
Parameters:
output_dir (str, optional): Directory to save generated audio files.
Defaults to 'backend/story_audio' if not provided.
"""
if output_dir:
self.output_dir = Path(output_dir)
else:
# Default to backend/story_audio directory
base_dir = Path(__file__).parent.parent.parent
self.output_dir = base_dir / "story_audio"
# Create output directory if it doesn't exist
self.output_dir.mkdir(parents=True, exist_ok=True)
logger.info(f"[StoryAudioGeneration] Initialized with output directory: {self.output_dir}")
def _generate_audio_filename(self, scene_number: int, scene_title: str) -> str:
"""Generate a unique filename for a scene audio file."""
# Clean scene title for filename
clean_title = "".join(c if c.isalnum() or c in ('-', '_') else '_' for c in scene_title[:30])
unique_id = str(uuid.uuid4())[:8]
return f"scene_{scene_number}_{clean_title}_{unique_id}.mp3"
def _generate_audio_gtts(
self,
text: str,
output_path: Path,
lang: str = "en",
slow: bool = False
) -> bool:
"""
Generate audio using Google Text-to-Speech (gTTS).
Parameters:
text (str): Text to convert to speech.
output_path (Path): Path to save the audio file.
lang (str): Language code (default: "en").
slow (bool): Whether to speak slowly (default: False).
Returns:
bool: True if generation was successful, False otherwise.
"""
try:
from gtts import gTTS
# Generate speech
tts = gTTS(text=text, lang=lang, slow=slow)
# Save to file
tts.save(str(output_path))
logger.info(f"[StoryAudioGeneration] Generated audio using gTTS: {output_path}")
return True
except ImportError as e:
logger.error(f"[StoryAudioGeneration] gTTS not installed. ImportError: {e}. Install with: pip install gtts")
return False
except Exception as e:
logger.error(f"[StoryAudioGeneration] Error generating audio with gTTS: {type(e).__name__}: {e}")
return False
def _generate_audio_pyttsx3(
self,
text: str,
output_path: Path,
rate: int = 150,
voice: Optional[str] = None
) -> bool:
"""
Generate audio using pyttsx3 (offline TTS).
Parameters:
text (str): Text to convert to speech.
output_path (Path): Path to save the audio file.
rate (int): Speech rate (default: 150).
voice (str, optional): Voice ID to use.
Returns:
bool: True if generation was successful, False otherwise.
"""
try:
import pyttsx3
# Initialize TTS engine
engine = pyttsx3.init()
# Set speech rate
engine.setProperty('rate', rate)
# Set voice if provided
if voice:
voices = engine.getProperty('voices')
for v in voices:
if voice in v.id:
engine.setProperty('voice', v.id)
break
# Generate speech and save to file
engine.save_to_file(text, str(output_path))
engine.runAndWait()
logger.info(f"[StoryAudioGeneration] Generated audio using pyttsx3: {output_path}")
return True
except ImportError:
logger.error("[StoryAudioGeneration] pyttsx3 not installed. Install with: pip install pyttsx3")
return False
except Exception as e:
logger.error(f"[StoryAudioGeneration] Error generating audio with pyttsx3: {e}")
return False
def generate_scene_audio(
self,
scene: Dict[str, Any],
user_id: str,
provider: str = "gtts",
lang: str = "en",
slow: bool = False,
rate: int = 150
) -> Dict[str, Any]:
"""
Generate audio narration for a single story scene.
Parameters:
scene (Dict[str, Any]): Scene data with audio_narration text.
user_id (str): Clerk user ID for subscription checking (for future usage tracking).
provider (str): TTS provider to use ("gtts", "pyttsx3", etc.).
lang (str): Language code for TTS (default: "en").
slow (bool): Whether to speak slowly (default: False, gTTS only).
rate (int): Speech rate (default: 150, pyttsx3 only).
Returns:
Dict[str, Any]: Audio metadata including file path, URL, and scene info.
"""
scene_number = scene.get("scene_number", 0)
scene_title = scene.get("title", "Untitled")
audio_narration = scene.get("audio_narration", "")
if not audio_narration:
raise ValueError(f"Scene {scene_number} ({scene_title}) has no audio_narration")
try:
logger.info(f"[StoryAudioGeneration] Generating audio for scene {scene_number}: {scene_title}")
logger.debug(f"[StoryAudioGeneration] Audio narration: {audio_narration[:100]}...")
# Generate audio filename
audio_filename = self._generate_audio_filename(scene_number, scene_title)
audio_path = self.output_dir / audio_filename
# Generate audio based on provider
success = False
if provider == "gtts":
success = self._generate_audio_gtts(
text=audio_narration,
output_path=audio_path,
lang=lang,
slow=slow
)
elif provider == "pyttsx3":
success = self._generate_audio_pyttsx3(
text=audio_narration,
output_path=audio_path,
rate=rate
)
else:
# Default to gTTS
logger.warning(f"[StoryAudioGeneration] Unknown provider '{provider}', using gTTS")
success = self._generate_audio_gtts(
text=audio_narration,
output_path=audio_path,
lang=lang,
slow=slow
)
if not success or not audio_path.exists():
raise RuntimeError(f"Failed to generate audio file: {audio_path}")
# Get file size
file_size = audio_path.stat().st_size
logger.info(f"[StoryAudioGeneration] Saved audio to: {audio_path} ({file_size} bytes)")
# Return audio metadata
return {
"scene_number": scene_number,
"scene_title": scene_title,
"audio_path": str(audio_path),
"audio_filename": audio_filename,
"audio_url": f"/api/story/audio/{audio_filename}", # API endpoint to serve audio
"provider": provider,
"file_size": file_size,
}
except HTTPException:
# Re-raise HTTPExceptions (e.g., 429 subscription limit)
raise
except Exception as e:
logger.error(f"[StoryAudioGeneration] Error generating audio for scene {scene_number}: {e}")
raise RuntimeError(f"Failed to generate audio for scene {scene_number}: {str(e)}") from e
def generate_scene_audio_list(
self,
scenes: List[Dict[str, Any]],
user_id: str,
provider: str = "gtts",
lang: str = "en",
slow: bool = False,
rate: int = 150,
progress_callback: Optional[callable] = None
) -> List[Dict[str, Any]]:
"""
Generate audio narration for multiple story scenes.
Parameters:
scenes (List[Dict[str, Any]]): List of scene data with audio_narration text.
user_id (str): Clerk user ID for subscription checking.
provider (str): TTS provider to use ("gtts", "pyttsx3", etc.).
lang (str): Language code for TTS (default: "en").
slow (bool): Whether to speak slowly (default: False, gTTS only).
rate (int): Speech rate (default: 150, pyttsx3 only).
progress_callback (callable, optional): Callback function for progress updates.
Returns:
List[Dict[str, Any]]: List of audio metadata for each scene.
"""
if not scenes:
raise ValueError("No scenes provided for audio generation")
logger.info(f"[StoryAudioGeneration] Generating audio for {len(scenes)} scenes")
audio_results = []
total_scenes = len(scenes)
for idx, scene in enumerate(scenes):
try:
# Generate audio for scene
audio_result = self.generate_scene_audio(
scene=scene,
user_id=user_id,
provider=provider,
lang=lang,
slow=slow,
rate=rate
)
audio_results.append(audio_result)
# Call progress callback if provided
if progress_callback:
progress = ((idx + 1) / total_scenes) * 100
progress_callback(progress, f"Generated audio for scene {scene.get('scene_number', idx + 1)}")
logger.info(f"[StoryAudioGeneration] Generated audio {idx + 1}/{total_scenes}")
except Exception as e:
logger.error(f"[StoryAudioGeneration] Failed to generate audio for scene {idx + 1}: {e}")
# Continue with next scene instead of failing completely
# Use empty strings for required fields instead of None
audio_results.append({
"scene_number": scene.get("scene_number", idx + 1),
"scene_title": scene.get("title", "Untitled"),
"audio_filename": "",
"audio_url": "",
"provider": provider,
"file_size": 0,
"error": str(e),
})
logger.info(f"[StoryAudioGeneration] Generated {len(audio_results)} audio files out of {total_scenes} scenes")
return audio_results
def generate_ai_audio(
self,
scene_number: int,
scene_title: str,
text: str,
user_id: str,
voice_id: str = "Wise_Woman",
speed: float = 1.0,
volume: float = 1.0,
pitch: float = 0.0,
emotion: str = "happy",
) -> Dict[str, Any]:
"""
Generate AI audio for a single scene using main_audio_generation.
Parameters:
scene_number (int): Scene number.
scene_title (str): Scene title.
text (str): Text to convert to speech.
user_id (str): Clerk user ID for subscription checking.
voice_id (str): Voice ID for AI audio generation (default: "Wise_Woman").
speed (float): Speech speed (0.5-2.0, default: 1.0).
volume (float): Speech volume (0.1-10.0, default: 1.0).
pitch (float): Speech pitch (-12 to 12, default: 0.0).
emotion (str): Emotion for speech (default: "happy").
Returns:
Dict[str, Any]: Audio metadata including file path, URL, and scene info.
"""
if not text or not text.strip():
raise ValueError(f"Scene {scene_number} ({scene_title}) requires non-empty text")
try:
logger.info(f"[StoryAudioGeneration] Generating AI audio for scene {scene_number}: {scene_title}")
logger.debug(f"[StoryAudioGeneration] Text length: {len(text)} characters, voice: {voice_id}")
# Import main_audio_generation
from services.llm_providers.main_audio_generation import generate_audio
# Generate audio using main_audio_generation service
result = generate_audio(
text=text.strip(),
voice_id=voice_id,
speed=speed,
volume=volume,
pitch=pitch,
emotion=emotion,
user_id=user_id,
)
# Save audio to file
audio_filename = self._generate_audio_filename(scene_number, scene_title)
audio_path = self.output_dir / audio_filename
with open(audio_path, "wb") as f:
f.write(result.audio_bytes)
logger.info(f"[StoryAudioGeneration] Saved AI audio to: {audio_path} ({result.file_size} bytes)")
# Calculate cost (for response)
character_count = result.text_length
cost_per_1000_chars = 0.05
cost = (character_count / 1000.0) * cost_per_1000_chars
# Return audio metadata
return {
"scene_number": scene_number,
"scene_title": scene_title,
"audio_path": str(audio_path),
"audio_filename": audio_filename,
"audio_url": f"/api/story/audio/{audio_filename}",
"provider": result.provider,
"model": result.model,
"voice_id": result.voice_id,
"text_length": result.text_length,
"file_size": result.file_size,
"cost": cost,
}
except HTTPException:
# Re-raise HTTPExceptions (e.g., 429 subscription limit)
raise
except Exception as e:
logger.error(f"[StoryAudioGeneration] Error generating AI audio for scene {scene_number}: {e}")
raise RuntimeError(f"Failed to generate AI audio for scene {scene_number}: {str(e)}") from e