1 files changed, 60 insertions, 0 deletions
diff --git a/o3d/utils/cross/dataurl.cc b/o3d/utils/cross/dataurl.cc
index 8334b8d..f796719 100644
--- a/o3d/utils/cross/dataurl.cc
+++ b/o3d/utils/cross/dataurl.cc
@@ -48,6 +48,66 @@ String ToDataURL(const String& mime_type, const void* data, size_t length) {
   return result;
 }
 
+// Decodes the data URL and stores a pointer to the data in dst_buffer
+bool FromDataURL(const String& data_url,
+                 scoped_array<uint8>* dst_buffer,
+                 size_t* output_length,
+                 String* error_string) {
+    // First parse the data_url
+  const String kDataHeader("data:");
+  const String kBase64Header(";base64,");
+  // The string has to be long enough.
+  if (data_url.size() <= kDataHeader.size() + kBase64Header.size()) {
+    *error_string = "Invalid formatting: The data URL is not long enough.";
+    return false;
+  }
+  // it must start with "data:"
+  if (data_url.compare(0, kDataHeader.size(), kDataHeader) != 0) {
+    *error_string
+        = "Invalid formatting: The data URL must start with 'data:'";
+    return false;
+  }
+  // we only support base64 data URL's
+  String::size_type data_index = data_url.find(kBase64Header);
+  if (data_index == String::npos) {
+    *error_string
+        = "Invalid formatting: The data URL have ';base64,' in the header.";
+    return false;
+  }
+  // The start of the data.
+  data_index += kBase64Header.size();
+  if (data_index >= data_url.size()) {
+    *error_string
+        = "Invalid formatting: There must be data in the body of the data URL.";
+    return false;
+  }
+
+  // Get the length of the decoded data
+  size_t input_length = data_url.size() - data_index;
+  base64::DecodeStatus return_code = base64::GetDecodeLength(
+      &data_url[data_index],
+      input_length,
+      output_length);
+  if (return_code != base64::kSuccess) {
+    if (return_code == base64::kPadError) {
+      *error_string
+          = "Invalid formatting: Padding error in the data URL data.";
+    } else {
+      *error_string
+          = "Invalid formatting: Bad character error in the data URL data.";
+    }
+    return false;
+  }
+
+  dst_buffer->reset(new uint8[*output_length]);
+  base64::Decode(&data_url[data_index],
+                 input_length,
+                 dst_buffer->get(),
+                 (*output_length));
+
+  return true;
+}
+
 }  // namespace dataurl
 }  // namespace o3d