refactor: extract _process_subtitle_file domain logic to shared modules

- domain/subtitle_processor.py: parse_subtitle_file, format_time_range,
  speed_up_audio, fit_audio_to_duration (moved from audio_buffer),
  process_subtitle_entries (core TTS loop with cancel/log/progress callbacks)
- domain/audio_buffer.py: add fit_audio_to_duration, ffmpeg_time_stretch
- domain/output_paths.py: add resolve_unique_path (collision-safe filename)
- pyqt/conversion.py: _process_subtitle_file reduced from ~350 to ~100 lines
  by delegating to domain functions; removed 4 unused subtitle parser imports
- +33 tests (8 resolve_unique_path, 14 subtitle_processor, 8 audio_buffer,
  3 format_time_range)
- 1153 tests pass
This commit is contained in:
Artem Akymenko
2026-07-19 09:34:17 +00:00
parent 380cdee0cb
commit 0e216f3786
7 changed files with 698 additions and 261 deletions
+279
View File
@@ -0,0 +1,279 @@
"""Subtitle-to-audio processing pipeline.
Converts subtitle files (SRT/ASS/VTT/timestamp text) into audio by
generating TTS for each entry and mixing into a buffer.
"""
from __future__ import annotations
import logging
import time
from dataclasses import dataclass
from typing import Any, Callable, List, Optional, Tuple
import numpy as np
from abogen.domain.audio_buffer import (
create_silence,
fit_audio_to_duration,
ffmpeg_time_stretch,
mix_audio,
normalize_audio,
SAMPLE_RATE,
)
from abogen.domain.audio_helpers import to_float32
from abogen.domain.progress import calc_etr_str
from abogen.subtitle_utils import (
parse_ass_file,
parse_srt_file,
parse_vtt_file,
parse_timestamp_text_file,
)
logger = logging.getLogger(__name__)
@dataclass
class SubtitleEntry:
"""A single subtitle entry with timing."""
start: float
end: Optional[float]
text: str
def parse_subtitle_file(
file_path: str,
is_timestamp_text: bool = False,
) -> List[Tuple[float, Optional[float], str]]:
"""Parse a subtitle file into (start, end, text) tuples.
Args:
file_path: Path to subtitle file.
is_timestamp_text: Whether to treat as timestamp text file.
Returns:
List of (start_time, end_time, text) tuples.
"""
if is_timestamp_text:
return parse_timestamp_text_file(file_path)
import os
ext = os.path.splitext(file_path)[1].lower()
if ext == ".srt":
return parse_srt_file(file_path)
elif ext == ".vtt":
return parse_vtt_file(file_path)
else:
return parse_ass_file(file_path)
def format_time_range(
start: float,
end: Optional[float],
is_auto_end: bool = False,
) -> str:
"""Format a time range for display in logs.
Args:
start: Start time in seconds.
end: End time in seconds, or None.
is_auto_end: Whether end time is auto-detected.
Returns:
Formatted string like "00:01:23,456 - 00:01:25,789" or "00:01:23 - AUTO".
"""
def _fmt(seconds: float) -> str:
h = int(seconds // 3600)
m = int(seconds % 3600 // 60)
s = int(seconds % 60)
ms = int((seconds - int(seconds)) * 1000)
result = f"{h:02d}:{m:02d}:{s:02d}"
if ms > 0:
result += f",{ms:03d}"
return result
if is_auto_end or end is None:
return f"{_fmt(start)} - AUTO"
return f"{_fmt(start)} - {_fmt(end)}"
def speed_up_audio(
audio: np.ndarray,
speed_factor: float,
method: str = "tts",
*,
backend: Any = None,
text: str = "",
voice: Any = None,
base_speed: float = 1.0,
sample_rate: int = SAMPLE_RATE,
) -> np.ndarray:
"""Speed up audio to fit a time window.
Args:
audio: Input audio buffer.
speed_factor: Required speed multiplier.
method: "ffmpeg" for time-stretch, "tts" for regeneration.
backend: TTS backend (required if method="tts").
text: Text to regenerate (required if method="tts").
voice: Voice to use for regeneration.
base_speed: Base speed for TTS.
sample_rate: Sample rate.
Returns:
Speed-adjusted audio buffer.
"""
if speed_factor <= 1.0:
return audio
if method == "ffmpeg":
logger.info("FFmpeg time-stretch: %.2fx", speed_factor)
return ffmpeg_time_stretch(audio, speed_factor, sample_rate)
# TTS regeneration
if backend is None:
return audio
new_speed = base_speed * speed_factor
logger.info("Regenerating at %.2fx speed", new_speed)
results = [
r for r in backend(text, voice=voice, speed=new_speed, split_pattern=None)
]
chunks = [r.audio for r in results]
if not chunks:
return audio
return np.concatenate([to_float32(c) for c in chunks])
def process_subtitle_entries(
subtitles: List[Tuple[float, Optional[float], str]],
*,
backend: Any,
voice: Any,
speed: float = 1.0,
cancel_check: Callable[[], bool] = lambda: False,
log_callback: Optional[Callable[[str], None]] = None,
progress_callback: Optional[Callable[[int, str], None]] = None,
replace_newlines: bool = True,
use_gaps: bool = False,
is_timestamp_text: bool = False,
subtitle_speed_method: str = "tts",
sample_rate: int = SAMPLE_RATE,
) -> np.ndarray:
"""Process subtitle entries: generate TTS for each and mix into buffer.
This is the core domain logic for subtitle-to-audio conversion.
UI-specific concerns (signals, widgets) are handled via callbacks.
Args:
subtitles: List of (start, end, text) tuples.
backend: TTS pipeline callable.
voice: Resolved voice for TTS.
speed: TTS speed.
cancel_check: Returns True if processing should stop.
log_callback: Called with log messages.
progress_callback: Called with (percent, etr_string).
replace_newlines: Replace \\n with spaces in text.
use_gaps: Whether to use silent gaps between subtitles.
is_timestamp_text: Whether input is timestamp text.
subtitle_speed_method: "ffmpeg" or "tts" for speed adjustment.
sample_rate: Audio sample rate.
Returns:
Mixed audio buffer (float32).
"""
if not subtitles:
return np.array([], dtype="float32")
max_end = max((end for _, end, _ in subtitles if end is not None), default=0)
buffer_samples = int(max_end * sample_rate) + sample_rate
audio_buffer = np.zeros(buffer_samples, dtype="float32")
etr_start = time.time()
total = len(subtitles)
for idx, (start_time, end_time, text) in enumerate(subtitles, 1):
if cancel_check():
break
processed_text = text.replace("\n", " ") if replace_newlines else text
next_start = (
subtitles[idx][0]
if (use_gaps and idx < total)
else float("inf")
)
subtitle_duration = None if end_time is None else end_time - start_time
is_auto_end = is_timestamp_text or (use_gaps and idx == total) or end_time is None
if log_callback:
log_callback(
f"\n[{idx}/{total}] {format_time_range(start_time, end_time, is_auto_end)}: {processed_text}"
)
# Generate TTS
results = [
r for r in backend(
processed_text, voice=voice, speed=speed, split_pattern=None
)
if not cancel_check()
]
if cancel_check():
break
audio_chunks = [r.audio for r in results]
full_audio = (
np.concatenate([to_float32(a) for a in audio_chunks])
if audio_chunks
else np.zeros(int((subtitle_duration or 0) * sample_rate), dtype="float32")
)
audio_duration = len(full_audio) / sample_rate
# Timing adjustment
if is_timestamp_text:
end_time = start_time + audio_duration
subtitle_duration = audio_duration
elif use_gaps:
end_time = min(start_time + audio_duration, next_start)
subtitle_duration = end_time - start_time
elif subtitle_duration is None:
subtitle_duration = audio_duration
end_time = start_time + audio_duration
# Speed up if needed
speedup_threshold = next_start - start_time if use_gaps else subtitle_duration
if audio_duration > speedup_threshold and speedup_threshold > 0:
speed_factor = audio_duration / speedup_threshold
full_audio = speed_up_audio(
full_audio, speed_factor,
method=subtitle_speed_method,
backend=backend, text=processed_text,
voice=voice, base_speed=speed,
sample_rate=sample_rate,
)
audio_duration = len(full_audio) / sample_rate
# Adjust duration after speed change
if use_gaps:
end_time = min(start_time + audio_duration, next_start)
subtitle_duration = end_time - start_time
elif subtitle_duration is None:
subtitle_duration = audio_duration
end_time = start_time + audio_duration
# Pad or trim to subtitle duration
full_audio = fit_audio_to_duration(full_audio, subtitle_duration, sample_rate)
# Mix into buffer
start_sample = int(start_time * sample_rate)
audio_buffer = mix_audio(audio_buffer, full_audio, start_sample)
# Progress
if progress_callback:
percent = min(int(idx / total * 100), 99)
etr = calc_etr_str(time.time() - etr_start, idx, total)
progress_callback(percent, etr)
# Normalize if needed
if np.abs(audio_buffer).max() > 1.0:
logger.info("Normalizing audio (peak: %.2f)", np.abs(audio_buffer).max())
audio_buffer = normalize_audio(audio_buffer)
return audio_buffer