Initial commit

Author: yusitnikov

.gitignore

@@ -0,0 +1 @@
+.idea

README.md

@@ -1,2 +1,63 @@
 # fix-webm-duration
-navigator.mediaDevices.getUserMedia + MediaRecorder create WEBM files without duration metadata. This library appends missing metadata section right to the file blob.
+
+`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);
+```
+
+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
+
+`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, 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' });
+        
+        ysFixWebmDuration(buggyBlob, duration, 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.