Publish Vulpes Preview 15 sources for desktop, Android and Tundra

Share Gaia assets and adapters, keep private profiles and development documents local, and update both public READMEs.

gaia/apps/camera/js/lib/prepare-preview-blob.js

@@ -0,0 +1,53 @@
+define(function(require, exports, module) {
+'use strict';
+
+/**
+ * Module Dependencies
+ */
+
+var parseJpegMetadata = require('jpegMetaDataParser');
+
+/**
+ * Exports
+ */
+
+module.exports = function(blob, done) {
+  parseJpegMetadata(blob, onJpegParsed);
+
+  function onJpegParsed(metadata) {
+    metadata.blob = blob;
+
+    if (!metadata.preview) {
+      done(metadata);
+      return;
+    }
+
+    // If we found an EXIF preview,
+    // and can determine its size, then
+    // we can display it instead of the
+    // big image and save memory and time.
+    var start = metadata.preview.start;
+    var end = metadata.preview.end;
+    var previewBlob = blob.slice(start, end, 'image/jpeg');
+    parseJpegMetadata(previewBlob, onSuccess, onError);
+
+    // If we parsed the preview image, add its
+    // dimensions to the metadata.preview
+    // object, and then let the MediaFrame
+    // object display the preview instead of
+    // the full-size image.
+    function onSuccess(previewMetadata) {
+       metadata.preview.width = previewMetadata.width;
+       metadata.preview.height = previewMetadata.height;
+       done(metadata);
+     }
+
+    // If we couldn't parse the preview image,
+    // just display full-size.
+    function onError() {
+      done(metadata);
+    }
+  }
+};
+
+});