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File Format Support

Closed Caption Creator supports over 30 different closed caption and subtitle file formats, covering a broad range of broadcast, streaming, and localization delivery requirements. Whether you are delivering EIA-608 captions for broadcast television, TTML for a streaming platform, or simple SRT files for online video, Closed Caption Creator provides the format coverage and profile options needed for professional workflows. If a format you require is not currently listed, the development team is available to evaluate and add support upon request.

Subtitle and Closed Caption Formats​

Closed Caption Creator supports an extensive library of subtitle and closed caption formats spanning legacy broadcast standards, modern streaming profiles, and platform-specific delivery requirements. The table below lists all currently supported subtitle and caption formats along with their associated file extensions.

FormatExtension
Scenerist V1.0.scc
MacCaption 608/708.mcc
EBU-STL.stl
Spruce STL.stl
WebVTT.vtt
SubRip.srt
Timed-Text Markup Language.ttml, .xml, .dfxp
Distribution Format Exchange Profile (DFXP).xml, .dfxp
Netflix DFXP.dfxp
Netflix TT Captions.xml
Netflix TT Subtitles.xml
IMSC Text Captions.xml, .ttml
IMSC Text Subtitles.xml, .ttml
SMPTE-TTML.xml, .ttml
EBU-TT.xml
MAGIC TT.xml
DLP Cinema.xml
DCDM Subtitle.xml
Verizon TTML.ttml
Bento MP4-DASH IMSC.mp4
iTunes Timed Text.itt
Substation Alpha.ssa
Advanced Substation Alpha.ass
Subviewer.sbv, .sub
Sofni.sub
Micro DVD.sub
DVD Architect.sub
Synchronized Accessible Media Interchange.smi, .sami
ScreenSystems Poliscript.pac
Cheetah (binary).cap
Videotron Lambda.cap
NCI Caption.cap
Cheetah (ASCII Text).asc
Cavena 890.890
Vitac.vni
Caption Inc..cin
Canvass SST Project.sdb
Avid DS.txt
Adobe Encore.txt
Apple DVD Studio Pro.txt
EZ Title.txt
PowerPixel Format.txt
ProCap Transfer.txt
QuickTime Text.txt
Eclipse.txt
Rich Text Format.rtf
Comma-Separated Values.csv
As-Broadcast Dialog List.docx, .csv
LMS Transcript.docx
Closed Caption Creator Project.ccprj
Google STT Transcript.json
Assembly AI STT Transcript.json
Deepgram STT Transcript.json
RevAI STT Transcript.json
Voicegain STT Transcript.json
Speechmatics STT Transcript.json
JSON.json

Transcript Import​

In addition to subtitle and caption formats, Closed Caption Creator supports importing plain transcript files for use as a starting point in captioning workflows. Transcripts can be imported and then timed manually or with the help of automatic synchronization tools.

FormatExtension
Plaintext.txt
Microsoft Word.docx
Comma Separated Value.csv

Video Playback​

Closed Caption Creator supports playback of video files in a wide range of codecs and containers. This allows you to load your source media directly without transcoding prior to captioning.

FormatNotes
H.264 / MPEG-4 AVCMost widely used delivery codec
HEVC (H.265)High-efficiency video for 4K and HDR
VP8, VP9WebM container
AV1Open, royalty-free codec
Ogg TheoraOpen format for web delivery

Audio Playback​

Audio-only files are supported for captioning and audio description workflows where video is not required or available.

FormatNotes
PCM WAVUncompressed, broadcast-grade audio
MP3Widely used compressed format
AACStandard for streaming and mobile
FLACLossless compressed audio
VorbisOpen lossy codec
OpusModern low-latency codec

Audio Description and Described Video Export​

When creating Audio Description or Described Video (DV) mixes, Closed Caption Creator can export the rendered audio output in the following formats.

FormatNotes
PCM WAVUp to 96 kHz sample rate
MP3Compressed delivery format
FLACLossless compressed output

Video Export with Burnt-In Subtitles​

Closed Caption Creator supports exporting video with subtitles rendered directly into the picture as open captions. Video export is available on the desktop application and supports custom font, style, and positioning settings.

FormatNotes
H.264Up to 4K resolution
Match SourcePreserves original video codec and container

Embedded Closed Captioning​

Closed Caption Creator supports embedding EIA-608 and EIA-708 closed captioning directly into video files without re-encoding the video. The source and output files will match in terms of video quality, as no transcode or re-encoding of the video takes place during the embed process.

FormatNotes
Match SourceMOV, MXF, MPEG, MP4, and more

Closed caption embedding requires a Pro or Enterprise subscription. There is a flat rate cost of $2.00 per file plus $0.40 per GB of uploaded video.