Supported File Formats
Stellar uses files of different types to support subtitle, caption, audio description, voiceover and dubbing workflows.
This page lists the file formats Stellar supports, and what you can do with each one.
What the support levels mean
Each format is marked with one or more of the following:
| Level | What it means |
|---|---|
| Open and edit | Open the file in Stellar, make changes, and save your work. |
| View only | Open the file in Stellar to view its contents. The file cannot be edited. |
| Convert | Stellar can convert to and from this format, even where the file cannot be opened for editing directly. |
Some formats support more than one level. For example, a format marked Open and edit and Convert can be worked on directly in Stellar and used as a conversion source or target.
Subtitle file formats
The table below is as comprehensive as possible but subject to change as new formats arrive or are added.
| Format | Open and edit | View only | Convert |
|---|---|---|---|
| Apple STL | – | – | ✓ |
| ASS | ✓ | – | ✓ |
| CIP | ✓ | – | – |
| DFXP | – | ✓ | ✓ |
| EBU-TT | – | ✓ | ✓ |
| EBU-TT-D | – | ✓ | ✓ |
| EztXml | – | – | ✓ |
| FinalCut | – | – | ✓ |
| FinalCut BDN | – | – | ✓ |
| FoxIMSC | – | – | ✓ |
| FPC (Unicode PAC) | ✓ | – | – |
| Generic XML | – | – | ✓ |
| IMSC | – | ✓ | ✓ |
| IMSC – Rosetta | ✓ | – | – |
| ITT | – | ✓ | ✓ |
| JSON (various formats) | – | – | ✓ |
| LAMBDACAP | ✓ | – | ✓ |
| Ooona | ✓ | – | ✓ |
| PAC | ✓ | – | – |
| SAMI | – | ✓ | ✓ |
| SIF | – | ✓ | ✓ |
| SMI | – | – | ✓ |
| SMPTE-428 | – | – | ✓ |
| SMPTE-2052 | – | ✓ | ✓ |
| SMPTE-TT | – | ✓ | ✓ |
| SMPTE-TT-NBCU | – | ✓ | ✓ |
| Sony BDN | – | – | ✓ |
| SRT | ✓ | – | – |
| STL | ✓ | – | – |
| TTAL (Netflix) | ✓ | – | – |
| TTXT / TTML | – | ✓ | ✓ |
| ULT | – | ✓ | ✓ |
| VTRON | – | – | ✓ |
| WebVTT | – | ✓ | ✓ |
| XIF | – | ✓ | ✓ |
Closed caption formats
| Format | Open and Edit | View Only | Convert |
|---|---|---|---|
| Lambda CAP | – | – | ✓ |
| SCC | ✓ | – | – |
| SMPTE-TTCC | – | – | ✓ |
| Spruce BDN | – | – | ✓ |
| SUB | – | – | ✓ |
| TDS | ✓ | – | – |
| UTL | – | – | ✓ |
Audio description file formats
| Format | Open and Edit | Convert | Notes |
|---|---|---|---|
| SRTAD | ✓ | – | Open format from Yella Umbrella. |
| TTAL | ✓ | – | Netflix format. Also used for dubbing. |
| CSV script formats | – | ✓ | Various script formats supplied as CSV. |
Dubbing file formats
| Format | Open and Edit | Convert | Notes |
|---|---|---|---|
| TTAL | ✓ | – | Netflix format. Also used for audio description. |
| CSV script formats | – | ✓ | Various script formats supplied as CSV. |
Transcript file formats
Stellar supports transcripts in JSON, which are mostly AI word-list outputs.
Metadata file formats
Stellar supports YUMETA files, used for timed metadata tagging for video markup and compliance.
Audio file formats
Stellar supports WAV and OGG audio files.
Video and media file formats
Stellar supports the common video and media containers, including:
- AVI
- FLV
- M4V
- MKV
- MOV
- MP4
- MPG / MPEG
- MXF
- OGV
- PS
- TS
- WMV
For the full list of supported codecs and containers, see the FFmpeg supported formats list.