navigator.mediaDevices.getUserMedia + MediaRecorder create WEBM files without duration metadata. This library appends missing metadata section right to the file blob.
npm install @fix-webm-duration/fixnavigator.mediaDevices.getUserMedia + MediaRecorder create WEBM files without duration metadata.
This library appends missing metadata section right to the file blob.
Install from a package manager:
```
npm install @fix-webm-duration/fix
Then, the library could be imported:
`typescript`
import { fixWebmDuration } from "@fix-webm-duration/fix";
Syntax:
`typescript`
const newBlob = await fixWebmDuration(blob, duration, options = {});
where
- blob is Blob object with file contents from MediaRecorderduration
- is video duration in milliseconds (you should calculate it while recording the video)options
- is an object of options:options.logger
- - a callback for logging debug messages or false.console.debug
The callback should accept one argument - the message string.
By default, will be used for logging.false
Passing will disable the logging.
fixWebmDuration will parse and fix your file asynchronously and return the fixed blob once the result is ready.
If the original blob already contains duration metadata section and the duration value is not empty, the callback will receive it without any changes made.
Example:
`typescript
let mediaRecorder;
let mediaParts;
let startTime;
function startRecording(stream: MediaStream, options: MediaRecorderOptions) {
mediaParts = [];
mediaRecorder = new MediaRecorder(stream, options);
mediaRecorder.onstop = async () => {
const duration = Date.now() - startTime;
const buggyBlob = new Blob(mediaParts, { type: "video/webm" });
const fixedBlob = await fixWebmDuration(buggyBlob, duration)
displayResult(fixedBlob);
};
mediaRecorder.ondataavailable = (event) => {
var data = event.data;
if (data && data.size > 0) {
mediaParts.push(data);
}
};
mediaRecorder.start();
startTime = Date.now();
}
function stopRecording() {
mediaRecorder.stop();
}
function displayResult(blob: Blob) {
// ...
}
`
Note: this example is not a MediaRecorder` usage guide.