77 lines
2.4 KiB
Markdown
77 lines
2.4 KiB
Markdown
# fix-webm-duration
|
|
|
|
`navigator.mediaDevices.getUserMedia` + `MediaRecorder` create WEBM files without duration metadata.
|
|
|
|
This library appends missing metadata section right to the file blob.
|
|
|
|
## Usage
|
|
|
|
The library contains only one script `fix-webm-duration.js` and has no dependencies.
|
|
|
|
Syntax:
|
|
|
|
```javascript
|
|
ysFixWebmDuration(blob, duration, callback = undefined, options = {});
|
|
```
|
|
|
|
where
|
|
- `blob` is `Blob` object with file contents from `MediaRecorder`
|
|
- `duration` is video duration in milliseconds (you should calculate it while recording the video)
|
|
- `callback` is callback function that will receive fixed blob.
|
|
If omitted, a `Promise` object will be returned instead.
|
|
- `options` is an object of options:
|
|
- `options.logger` - a callback for logging debug messages or `false`.
|
|
The callback should accept one argument - the message string.
|
|
By default, `console.log` will be used for logging.
|
|
Passing `false` will disable the logging.
|
|
|
|
`ysFixWebmDuration` will parse and fix your file asynchronously and will call your callback 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:
|
|
|
|
```javascript
|
|
var mediaRecorder;
|
|
var mediaParts;
|
|
var startTime;
|
|
|
|
function startRecording(stream, options) {
|
|
mediaParts = [];
|
|
mediaRecorder = new MediaRecorder(stream, options);
|
|
mediaRecorder.onstop = function() {
|
|
var duration = Date.now() - startTime;
|
|
var buggyBlob = new Blob(mediaParts, { type: 'video/webm' });
|
|
|
|
// v1: callback-style
|
|
ysFixWebmDuration(buggyBlob, duration, function(fixedBlob) {
|
|
displayResult(fixedBlob);
|
|
});
|
|
|
|
// v2: promise-style, disable logging
|
|
ysFixWebmDuration(buggyBlob, duration, {logger: false})
|
|
.then(function(fixedBlob) {
|
|
displayResult(fixedBlob);
|
|
});
|
|
};
|
|
mediaRecorder.ondataavailable = function(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) {
|
|
// ...
|
|
}
|
|
```
|
|
|
|
Note: this example **is not** a `MediaRecorder` usage guide.
|