Media
Convert subtitles between WebVTT, TTML (with SMPTE frame timing and styles), YouTube SBV and SRT — frame-precision time axes (23.976/24/25/29.97 drop-frame/30/50/59.94 DF/60), TTML tts styles bridged to WebVTT ::cue CSS, cue-id uniqueness, and IMSC 1.0.1 compatibility checks.
Call this tool from your code in three languages.
# 1) Request a presigned URL → returns { uploadUrl, storageKey }
curl -X POST 'http://127.0.0.1:3003/api/upload/presign/webvtt-ttml-sbv-subtitle-time-axis-and-cue-style-converter' \
-H 'Content-Type: application/json' \
-d '{"filename":"sourceFile.ext","contentType":"application/octet-stream","size":12345}'
# 2) PUT the file bytes directly to the presigned uploadUrl
curl -X PUT '<presigned uploadUrl>' \
--data-binary @/path/to/file.ext
# 3) Call the tool, passing the returned storageKey for each file field
curl -X POST 'http://127.0.0.1:3003/en/api/tools/webvtt-ttml-sbv-subtitle-time-axis-and-cue-style-converter' \
-F 'source=1
00:00:01,000 --> 00:00:04,000
Hello <i>world</i>!
2
00:00:05,500 --> 00:00:06,000
Second & <b>bold</b> cue' \
-F 'sourceFile=uploads/2026/01/01/your-tool-1700000000000-abc123.ext' \
-F 'sourceFormat=auto' \
-F 'targetFormat=webvtt' \
-F 'fps=auto' \
-F 'smpteTimes=false' \
-F 'validateImsc=true' \
-F 'outputLang=en'Send a POST request with your inputs as JSON. File parameters require a separate upload first.
POST http://127.0.0.1:3003/en/api/tools/webvtt-ttml-sbv-subtitle-time-axis-and-cue-style-converter| Name | Type | Required | Description |
|---|---|---|---|
| source | textarea | No | — |
| sourceFile | fileupload required | No | — |
| sourceFormat | select | Yes | — |
| targetFormat | select | Yes | — |
| fps | select | Yes | — |
| smpteTimes | checkbox | No | — |
| validateImsc | checkbox | No | — |
| outputLang | text | No | — |
Text result
{
"result": "Processed text content",
"error": "Error message (optional)",
"message": "Notification message (optional)",
"metadata": {
"key": "value"
}
}Add this tool to your Model Context Protocol server so AI agents can list and call it.
Add this block to your MCP client configuration:
{
"mcpServers": {
"elysiatools-webvtt-ttml-sbv-subtitle-time-axis-and-cue-style-converter": {
"name": "webvtt-ttml-sbv-subtitle-time-axis-and-cue-style-converter",
"description": "Convert subtitles between WebVTT, TTML (with SMPTE frame timing and styles), YouTube SBV and SRT — frame-precision time axes (23.976/24/25/29.97 drop-frame/30/50/59.94 DF/60), TTML tts styles bridged to WebVTT ::cue CSS, cue-id uniqueness, and IMSC 1.0.1 compatibility checks.",
"baseUrl": "http://127.0.0.1:3003/mcp/sse?toolId=webvtt-ttml-sbv-subtitle-time-axis-and-cue-style-converter",
"command": "",
"args": [],
"env": {},
"isActive": true,
"type": "sse"
}
}
}After connecting to the SSE endpoint, list the exposed tools:
{
"jsonrpc": "2.0",
"id": 1,
"method": "tools/list"
}Invoke the tool by its id, passing arguments built from its parameters:
{
"jsonrpc": "2.0",
"id": 2,
"method": "tools/call",
"params": {
"name": "webvtt-ttml-sbv-subtitle-time-axis-and-cue-style-converter",
"arguments": {
"source": "1\n00:00:01,000 --> 00:00:04,000\nHello <i>world</i>!\n\n2\n00:00:05,500 --> 00:00:06,000\nSecond & <b>bold</b> cue",
"sourceFile": "https://example.com/file.ext",
"sourceFormat": "auto",
"targetFormat": "webvtt",
"fps": "auto",
"smpteTimes": false,
"validateImsc": true,
"outputLang": "en"
}
}
}Questions or issues? Contact [email protected]