* chore(deps): update subby to 0.3.27
* fix(subs): add WVTT (WebVTT in MP4) subtitle converter for subby
- Use WVTTConverter if self.codec == Subtitle.Codec.fVTT
- Read or save files as Paths instead of strings to avoid AttributeErrors
- Add CommonIssuesFixer when stripping SDH
- Set Subtitle.Codec.fVTT to use subby if conversion_method == "auto"
- Silence the underlying srt library logging used by subby to avoid info messages being printed to console
- Use lowercase format names (subrip, webvtt, advancedsubstationalpha) to match SubtitleEdit 4.x CLI requirements
- Change /Convert to /convert for consistency with CLI docs
- Convert Path objects to strings explicitly for subprocess calls
- Respect conversion_method config in SDH stripping - skip SubtitleEdit when user has set pysubs2/pycaption/subby as their preferred method
- Add stderr suppression to SubtitleEdit calls
Some services use WebVTT files with:
- Cue identifiers (Q0, Q1, etc.) before timing lines that pysubs2/pycaption incorrectly parses as subtitle text
- Multi-line subtitles split into separate cues with 1ms offset times and different line: positions (e.g., line:77% for top, line:84% for bottom)
Added detection and sanitization functions:
- has_webvtt_cue_identifiers(): detects cue identifiers before timing
- sanitize_webvtt_cue_identifiers(): removes problematic cue identifiers
- has_overlapping_webvtt_cues(): detects overlapping cues needing merge
- merge_overlapping_webvtt_cues(): merges cues sorted by line position
The previous regex only matched negative size values when they were the entire quoted attribute (e.g., "-5%"). This failed for multi-value attributes like tts:extent="-5% 7.5%" causing pycaption parse errors.
The new pattern matches negative values anywhere in the text and preserves the unit during replacement.
Closes#47
Add preserve_formatting config option to prevent automatic subtitle processing that strips formatting tags and styling. When enabled (default: true), WebVTT files skip pycaption read/write cycle to preserve tags like <i>, <b>, positioning, and other formatting.
- Add pysubs2 as default conversion method for 'auto' mode
- Add support for MicroDVD (.sub), MPL2 (.mpl2), and TMP (.tmp) formats
- Implement convert_with_pysubs2() method with fallback to standard conversion
- Update from_mime() to handle new subtitle format types
- Map all supported formats to pysubs2 format identifiers
- Update docstrings to reflect new capabilities
