DFXP
Distribution Format Exchange Profile
An older subtitle profile of TTML used by Netflix and Adobe Flash. Internally just TTML XML with a .dfxp extension.
In depth
DFXP (Distribution Format Exchange Profile) is a TTML 1.0 profile originally used by Adobe Flash captions and adopted by Netflix's pre-IMSC ingest pipeline. The .dfxp file is XML — open one in a text editor and you'll see the same <tt><body><div><p> structure as TTML. Modern ingest pipelines have largely moved to IMSC, but legacy archives and older DAM systems still store .dfxp files.
When to use it
Convert .dfxp to SRT or VTT for almost any modern workflow. Only keep DFXP if a legacy delivery spec specifically requires it.
Frequently asked
Is DFXP the same as TTML?+
Practically yes. DFXP is a profile of TTML 1.0 — the file structure is identical XML. You can usually rename .dfxp to .xml and a TTML parser will read it.
How do I convert DFXP to SRT?+
Run it through any TTML-aware converter. DaVinci Resolve and Premiere can import DFXP and re-export as SRT, or use a command-line tool like ttml2srt.
Why is DFXP still around?+
Broadcast and streaming archives that were ingested before IMSC took over (roughly pre-2017) often store captions as DFXP. Re-encoding the entire library would be expensive, so the format persists.
An XML-based subtitle format used by streaming services and broadcast workflows. Powerful styling and positioning, but verbose.
The most common subtitle file format. Plain text with numbered cues and HH:MM:SS,mmm timestamps.
The W3C web standard for subtitles. Used by HTML5 <track> elements. Like SRT but with dot-separated milliseconds and styling support.