CJK caption support, Windows fixes, EDL-level style/audio overrides

[Jerryxumaomao]

Four improvements from editing a real Chinese vertical-video (XHS) project with video-use on Windows. Each commit is independent and revertable.

1. fix: Windows subtitle path escaping (413fcf3)

render.py escaped the drive colon in the subtitles filter path but left raw backslashes, which ffmpeg's filter parser eats (D\:\Users\... → broken). Normalizing to forward slashes fixes subtitle burning on Windows.

2. feat: EDL-level subtitle_style + CJK phrase-level caption chunking (a8161f2)

• edl.json may now carry a subtitle_style ASS force_style string, overriding SUB_FORCE_STYLE per project (different platforms/languages want different caption looks without patching the helper).
• Chinese/CJK ASR tokens arrive per-character; the 2-word chunker produced captions like 天 天 / 气 不 with orphaned punctuation. CJK text now accumulates into phrase-level cues (break on CJK punctuation or 10 chars), joined without spaces, punctuation-only tokens act as break markers and are never displayed. Latin behavior unchanged.

3. fix: scale overlays to base resolution before compositing (c401166)

ffmpeg's overlay crops (not scales) oversized inputs. Full-res overlay assets rendered against --preview/--draft bases were silently cropped off-frame. Overlays are now scaled to the probed base dimensions first.

4. feat: EDL-level audio_filter + strip all punctuation from CJK captions (d2a9485)

• edl.json audio_filter runs before the 30ms edge fades in every segment extract — e.g. afftdn denoise or an EQ chain for muddy on-camera mics.
• CJK captions now drop ALL punctuation (incl. curly quotes) — cleaner on screen; phrase breaks already encode the rhythm.

Tested end-to-end on Windows 10 (Git Bash + PowerShell), ffmpeg 8.1.2, ElevenLabs Scribe zh transcription, 1728x3072 portrait sources: full pipeline transcribe → EDL → cutaway overlays + PIL animation slots → burned phrase-level Chinese subtitles → loudnorm.

🤖 Generated with Claude Code

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Summary by cubic

Add CJK-friendly captions and per-project EDL overrides for subtitle style and audio processing, plus fix Windows subtitle path parsing and overlay cropping. Improves Chinese caption quality and makes Windows renders reliable.

• New Features

  • EDL subtitle_style to override ASS force_style per project.
  • CJK captions: phrase-level chunking (break on CJK punctuation or 10 chars), no inter-character spaces, all punctuation removed.
  • EDL audio_filter runs before the 30ms edge fades in segment extraction (e.g., afftdn, EQ).

• Bug Fixes

  • Windows: normalize subtitle file paths to forward slashes inside ffmpeg filters to prevent parsing errors.
  • Scale overlay inputs to the base resolution before compositing to avoid cropping on preview/draft renders.

^{Written for commit d2a9485. Summary will update on new commits.}

[cubic-dev-ai]

No issues found across 1 file

_{Re-trigger cubic}