Decode h264 fmtp sprop-parameter-sets to binary.

BUG=webrtc:5948

Review-Url: https://codereview.webrtc.org/2544493005
Cr-Commit-Position: refs/heads/master@{#15474}

webrtc/modules/video_coding/h264_sprop_parameter_sets.cc

@@ -0,0 +1,57 @@
+/*
+ *  Copyright (c) 2016 The WebRTC 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 "webrtc/modules/video_coding/h264_sprop_parameter_sets.h"
+
+#include <string>
+#include <vector>
+
+#include "webrtc/base/base64.h"
+#include "webrtc/base/basictypes.h"
+#include "webrtc/base/logging.h"
+
+namespace {
+
+bool DecodeAndConvert(const std::string& base64, std::vector<uint8_t>* binary) {
+  // TODO(johan): Directly decode to std::vector<uint8_t> when available.
+  std::vector<char> tmp;
+  if (!rtc::Base64::DecodeFromArray(base64.data(), base64.size(),
+                                    rtc::Base64::DO_STRICT, &tmp, nullptr)) {
+    return false;
+  }
+  const uint8_t* data = reinterpret_cast<uint8_t*>(tmp.data());
+  binary->assign(data, data + tmp.size());
+  return true;
+}
+}  // namespace
+
+namespace webrtc {
+
+bool H264SpropParameterSets::DecodeSprop(const std::string& sprop) {
+  size_t separator_pos = sprop.find(',');
+  if ((separator_pos <= 0) || (separator_pos >= sprop.length() - 1)) {
+    LOG(LS_WARNING) << "Invalid seperator position " << separator_pos << " *"
+                    << sprop << "*";
+    return false;
+  }
+  std::string sps_str = sprop.substr(0, separator_pos);
+  std::string pps_str = sprop.substr(separator_pos + 1, std::string::npos);
+  if (!DecodeAndConvert(sps_str, &sps_)) {
+    LOG(LS_WARNING) << "Failed to decode sprop/sps *" << sprop << "*";
+    return false;
+  }
+  if (!DecodeAndConvert(pps_str, &pps_)) {
+    LOG(LS_WARNING) << "Failed to decode sprop/pps *" << sprop << "*";
+    return false;
+  }
+  return true;
+}
+
+}  // namespace webrtc