added dumpvtt app

Change-Id: I9eba00412bbd05641dafd1a6cfc4656bda8bb8c2

vttreader.cc

@@ -0,0 +1,57 @@
+// Copyright (c) 2012 The WebM project authors. All Rights Reserved.
+//
+// Use of this source code is governed by a BSD-style license
+// that can be found in the LICENSE file in the root of the source
+// tree. An additional intellectual property rights grant can be found
+// in the file PATENTS.  All contributing project authors may
+// be found in the AUTHORS file in the root of the source tree.
+
+#include "./vttreader.h"  // NOLINT
+
+namespace libwebvtt {
+
+VttReader::VttReader() : file_(NULL) {
+}
+
+VttReader::~VttReader() {
+  Close();
+}
+
+int VttReader::Open(const char* filename) {
+  if (filename == NULL || file_ != NULL)
+    return -1;
+
+  file_ = fopen(filename, "rb");
+  if (file_ == NULL)
+    return -1;
+
+  return 0;  // success
+}
+
+void VttReader::Close() {
+  if (file_) {
+    fclose(file_);
+    file_ = NULL;
+  }
+}
+
+int VttReader::GetChar(char* c) {
+  if (c == NULL || file_ == NULL)
+    return -1;
+
+  const int result = fgetc(file_);
+  if (result != EOF) {
+    *c = static_cast<char>(result);
+    return 0;  // success
+  }
+
+  if (ferror(file_))
+    return -1;  // error
+
+  if (feof(file_))
+    return 1;  // EOF
+
+  return -1;  // weird
+}
+
+}  // namespace libwebvtt