subtitle 0.2.0

A library that makes it easy to work with multiple subtitle/caption file formats, written with highly efficient code, highly customizable (90%), supports Null Safety.

0.2.0

Performance

• VTT and SRT parser rewritten as a line-based cue-block parser. The file is split on blank lines and only the --> timing line is matched with a regex, eliminating the catastrophic backtracking that caused multi-second hangs on large karaoke-style VTT files. (#21)
• multiDurationSearch is now O(log n + k) — an upper-bound binary search locates the candidate window, then a backwards walk with a precomputed prefix-max-end array terminates as soon as no further active cue is possible.
• Cue deduplication runs automatically after parsing and sorting. Same-range cues are collapsed to the longest text; contiguous cues with identical text and a gap ≤ 50 ms are merged into one. This keeps karaoke-style files manageable without losing visible content.

Fixes

• VTT cue identifiers (named cues such as intro or chapter-1) are now parsed correctly — cue names no longer bleed into .data. (#20)
• VTT positioning directives (line:, position:, align:, etc.) on the timing line are silently skipped; only the cue text that follows is extracted.
• Network and file fetching now attempt strict UTF-8 decoding first and fall back to Latin-1 for subtitle files served in legacy encodings. (#10)

API additions

• Subtitle.copyWith({index, data, start, end}) — creates a modified copy of a subtitle cue.

0.1.4

• Fix: Resolved issues related to new line handling in subtitle parsers.
• Test: Added comprehensive tests for all subtitle formats. (#18)
• Fix: Corrected regex handling for ttml_subtitle to ensure proper parsing.
• Improvement: Adjusted parsers to maintain \n consistency, aligning with VTT and SRT styles as intended by subtitle authors.

0.1.3

• Solved issue with StringSubtitle, see #16 for more.
• Added dispose for SubtitleController, see #11 for more.
• Solved issues #9 and #4 in #12, thanks for (@fadone).

0.1.0

• Addressed an issue with subtitle parsing (srt) that was affecting certain cases. This contribution is credited to @sahanForaty. Refer to issue #6.
• Resolved a network subtitle problem, contributed by @thecarry98. See issue #8.
• Corrected the issue associated with the unclosed HttpClient in the network subtitle handling.
• Added SRT format example.

0.1.0-beta.3

• Fix srt bug.
• Remove path package from dependency.
• Rewrite and enhance regular expressions.

0.1.0-beta.2

• Add SubtitleController and its feature like:
  • Binary search for single search by providing the duration.
  • Multi result search by providing the duration.
• Re-architect the files of project.
• Update regex of VttRegex and SrtRegex.
• Fix SubtitleParser bug when decoding the subtitles.
• You can normalize the subtitle text data while decoding, like remove css styles.
• Manual provide of the SubtitleType, or leave it to detected auto.
• Fix dart:io bug to support dart js and flutter web by using universal_io package.
• Reducing non-required dependency http package.
• 3 examples added.

0.1.0-beta.1

• SubtitleProvider: Simplifies fetching subtitle file data from multiple sources.
• SubtitleRepository: Deals with the platform directly to get or download the required data and submit it to the provider.
• SubtitleParser: Used to analyze and convert subtitle files into software objects that are viewable and usable.
• CustomSubtitleParser: Customizable subtitle parser, for custom regexes.
• SubtitleRegexObject: Responsible for providing the necessary expression for the purpose of decoding the content of subtitle files, has 4 children:
  • VttRegex: WebVTT regexp.
  • SrtRegex: SubRip regexp.
  • TtmlRegex: TTML or DFXP regex
  • CustomRegex: User define regexp.
• SubtitleObject: Store the subtitle file data and its format type.
• Initial version, created by MuhmdHsn313