by Loudness Films
v4.0100% local
Format Converter
Convert between subtitle formats with optional framerate retime.
Input file
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Drop subtitle file here or click to browse

SRT · VTT · ASS · TTML · SBV · LRC · SMPTE/Interop DCP XML · PAC (beta)
Editor
Load, view and edit. Full scroll, search, inline editing.
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SRT · VTT · ASS · TTML · SMPTE/Interop DCP XML · PAC (beta)
DCP Export
Export to DCP XML + font ZIP. Interop (CineCanvas), SMPTE 428-7:2010 and 2014.
Input subtitle file
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Drop .srt, .vtt, .ass, .pac — or use → DCP from Editor

Presets
Interop / CineCanvas
📎 Attach font
Timecode Tools
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01:00:00:00
hours
minutes
seconds
frames
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ms in
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ms out
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drift ms
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frames in
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frames out
Formats & Help
Output formats by category
FormatExtCategoryRWNotes
SubRip.srtWeb✓✓Universal, <i> <b> tags
WebVTT.vttWeb✓✓W3C web standard
SBV.sbvWeb✓✓YouTube
YouTube Timed Text.yttWeb—✓YTT / srv3 XML
SAMI.samiWeb—✓Microsoft / Windows Media
iTunes Timed Text.ittWeb—✓Apple TV / iTunes
Netflix TTAL.ttalWeb—✓Netflix delivery format
TTML / IMSC1.ttmlBroadcast✓✓W3C / EBU-TT
EBU STL.stlBroadcast—✓European broadcast (text repr.)
ASS / SSA.assBroadcast✓✓Full styling, karaoke
LRC.lrcBroadcast✓✓Lyrics format
RealText.rtBroadcast—✓RealMedia
Interop / CineCanvas.xmlDCP✓✓DCSubtitle root, TI spec. ZIP output.
SMPTE 428-7:2010.xmlDCP✓✓SubtitleReel, UUID font. ZIP output.
SMPTE 428-7:2014.xmlDCP✓✓Current standard, shadow effect. ZIP output.
FCPXML.fcpxmlNLE—✓Final Cut Pro X
Avid DS / Subcap.txtNLE—✓Avid subtitle track
Avid ALE.aleNLE—✓Avid Log Exchange
Smoke XML.xmlNLE—✓Autodesk Smoke
DVD Studio Pro STL.stlNLE—✓Spruce STL
CMX 3600.edlNLE—✓Edit Decision List
CSV.csvData—✓Full table with durations
Plain Text.txtData—✓Text only, no timecodes
USF.usfData—✓Universal Subtitle Format
PAC (Screen Electronics).pacImport onlyβ—Binary, reverse-engineered Latin parser
DCP notes & deployment

Interop — Root: DCSubtitle. Font URI = font filename (e.g. Arial.ttf). Fade in frames (not ticks). Legacy projectors.

SMPTE 428-7:2010 — Root: SubtitleReel, ns .../2010/DCST. Font UUID. Ticks = frames at edit rate.

SMPTE 428-7:2014 — ns .../2014/DCST. IssueDate: yyyy-mm-ddThh:mm:ss. Default effect: shadow. Required by DCP-o-matic, Clipster, EasyDCP validation.

Font auto-load — Uses queryLocalFonts() (Chrome 103+). Grant permission when prompted. Font is included in ZIP as UUID (SMPTE) or fontname.ttf (Interop). Packagers (DCP-o-matic, OpenDCP, EasyDCP) pick it up automatically.

Deploy to subtitles.loudness-films.pt — Create a new Cloudflare Pages project with this HTML file as index.html. In Cloudflare DNS add a CNAME record: subtitles → your Pages project URL. Done. queryLocalFonts() requires HTTPS — works on the published site, not on local file:// URLs.

PAC parser — Reverse-engineered Latin charset (Screen Electronics). Works for most Western European languages. Greek/Cyrillic PAC not supported. Timecodes decoded from BCD. No guaranteed format stability across PAC versions.