Add H264 bitstream rewriting to limit frame reordering marker in header

webrtc/base/bitbuffer.cc

 /*
  *  Copyright 2015 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.
  */
 
@@ skipping 275 matching lines @@
     return false;
   }
   uint64_t val_to_encode = static_cast<uint64_t>(val) + 1;
 
   // We need to write CountBits(val+1) 0s and then val+1. Since val (as a
   // uint64_t) has leading zeros, we can just write the total golomb encoded
   // size worth of bits, knowing the value will appear last.
   return WriteBits(val_to_encode, CountBits(val_to_encode) * 2 - 1);
 }
 
+bool BitBufferWriter::WriteSignedExponentialGolomb(int32_t val) {
+  if (val == 0) {
+    return WriteExponentialGolomb(0);
+  } else if (val > 0) {
+    uint32_t signed_val = val;
+    return WriteExponentialGolomb((signed_val * 2) - 1);
+  } else {
+    if (val == std::numeric_limits<int32_t>::min())
+      return false;  // Not supported, would cause overflow.
+    uint32_t signed_val = -val;
+    return WriteExponentialGolomb(signed_val * 2);
+  }
+}
+
 }  // namespace rtc