Add HE AAC support to ISO BMFF.

content/common/gpu/media/h264_bit_reader.cc

Index: content/common/gpu/media/h264_bit_reader.cc
diff --git a/content/common/gpu/media/h264_bit_reader.cc b/content/common/gpu/media/h264_bit_reader.cc
new file mode 100644
index 0000000000000000000000000000000000000000..b8d00e174a33ef36461c82dfc34b4046dc3f6fd5
--- /dev/null
+++ b/content/common/gpu/media/h264_bit_reader.cc
@@ -0,0 +1,45 @@
+// Copyright (c) 2012 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "content/common/gpu/media/h264_bit_reader.h"
+
+namespace content {
+
+H264BitReader::H264BitReader() {
+}
+
+H264BitReader::~H264BitReader() {}
+
+void H264BitReader::UpdateCurrByte() {
+  DCHECK_EQ(num_remaining_bits_in_curr_byte_, 0);
+
+  if (bytes_left_ >= 1) {
+    // Emulation prevention three-byte detection.
+    // If a sequence of 0x000003 is found, skip (ignore) the last byte (0x03).
+    if (*data_ == 0x03 && Tell() >= 16 && data_[-1] == 0 && data_[-2] == 0) {
+      // Detected 0x000003, skip last byte.
+      ++data_;
+      --bytes_left_;
+      position_ += 8;
+    }
+  }
+
+  if (bytes_left_ >= 1) {
+    // Load a new byte and advance pointers.
+    curr_byte_ = *data_;
+    ++data_;
+    --bytes_left_;
+    num_remaining_bits_in_curr_byte_ = 8;
+  }
+
+  // Check if this is the end of RBSP data.
+  if (bytes_left_ == 0) {
+    while (num_remaining_bits_in_curr_byte_ != 0 && !(curr_byte_ & 0x1)) {
+      --num_remaining_bits_in_curr_byte_;
+      curr_byte_ >>= 1;
+    }
+  }
+}
+
+}  // namespace content