Adding native encoders (#71)

* Adding browser png

* Adding native JPEG & file size output

* Removing log

* Fixing blob typing

* Fix timing issue

src/codecs/browser-jpeg/encoder.ts

@@ -0,0 +1,14 @@
+import { canvasEncode } from '../../lib/util';
+
+export interface EncodeOptions { quality: number; }
+export interface EncoderState { type: typeof type; options: EncodeOptions; }
+
+export const type = 'browser-jpeg';
+export const label = 'Browser JPEG';
+export const mimeType = 'image/jpeg';
+export const extension = 'jpg';
+export const defaultOptions: EncodeOptions = { quality: 0.5 };
+
+export function encode(data: ImageData, { quality }: EncodeOptions) {
+  return canvasEncode(data, mimeType, quality);
+}