add buffer and check base64 is parseable

example/package.json

     "@react-native-community/blur": "^3.4.1",
     "@react-native-community/masked-view": "^0.1.6",
     "@react-native-community/slider": "^2.0.8",
+    "buffer": "^5.4.3",
     "gl-react": "2",
     "gl-react-native": "2",
     "lodash": "^4.17.15",

example/src/Full.js

   Image,
 } from 'react-native';
 
+import { Buffer } from 'buffer';
 import * as ART from '@react-native-community/art';
 import Slider from '@react-native-community/slider';
 import omit from 'lodash/omit';
 
   const onCapture = useCallback(
     res => {
+      if (config.result === 'base64') {
+        const b = Buffer.from(res, 'base64');
+        console.log('buffer of length ' + b.length);
+      }
       setPreviewSource({
         uri: config.result === 'base64' ? 'data:image/' + config.format + ';base64,' + res : res,
       });

example/yarn.lock

   resolved "https://registry.yarnpkg.com/base-64/-/base-64-0.1.0.tgz#780a99c84e7d600260361511c4877613bf24f6bb"
   integrity sha1-eAqZyE59YAJgNhURxId2E78k9rs=
 
-base64-js@^1.1.2, base64-js@^1.2.3:
+base64-js@^1.0.2, base64-js@^1.1.2, base64-js@^1.2.3:
   version "1.3.1"
   resolved "https://registry.yarnpkg.com/base64-js/-/base64-js-1.3.1.tgz#58ece8cb75dd07e71ed08c736abc5fac4dbf8df1"
   integrity sha512-mLQ4i2QO1ytvGWFWmcngKO//JXAQueZvwEKtjgQFM4jIK0kU+ytMfplL8j+n5mspOfjHwoAg+9yhb7BwAHm36g==
   resolved "https://registry.yarnpkg.com/buffer-from/-/buffer-from-1.1.1.tgz#32713bc028f75c02fdb710d7c7bcec1f2c6070ef"
   integrity sha512-MQcXEUbCKtEo7bhqEs6560Hyd4XaovZlO/k9V3hjVUF/zwW7KBVdSK4gIt/bzwS9MbR5qob+F5jusZsb0YQK2A==
 
+buffer@^5.4.3:
+  version "5.4.3"
+  resolved "https://registry.yarnpkg.com/buffer/-/buffer-5.4.3.tgz#3fbc9c69eb713d323e3fc1a895eee0710c072115"
+  integrity sha512-zvj65TkFeIt3i6aj5bIvJDzjjQQGs4o/sNoezg1F1kYap9Nu2jcUdpwzRSJTHMMzG0H7bZkn4rNQpImhuxWX2A==
+  dependencies:
+    base64-js "^1.0.2"
+    ieee754 "^1.1.4"
+
 bytes@3.0.0:
   version "3.0.0"
   resolved "https://registry.yarnpkg.com/bytes/-/bytes-3.0.0.tgz#d32815404d689699f85a4ea4fa8755dd13a96048"
   dependencies:
     safer-buffer ">= 2.1.2 < 3"
 
+ieee754@^1.1.4:
+  version "1.1.13"
+  resolved "https://registry.yarnpkg.com/ieee754/-/ieee754-1.1.13.tgz#ec168558e95aa181fd87d37f55c32bbcb6708b84"
+  integrity sha512-4vf7I2LYV/HaWerSo3XmlMkp5eZ83i+/CDluXi/IGTs/O1sejBNhTtnxzmRZfvOUqj7lZjqHkeTvpgSFDlWZTg==
+
 ignore-walk@^3.0.1:
   version "3.0.1"
   resolved "https://registry.yarnpkg.com/ignore-walk/-/ignore-walk-3.0.1.tgz#a83e62e7d272ac0e3b551aaa82831a19b69f82f8"