Add HE AAC support to ISO BMFF.

Was https://chromiumcodereview.appspot.com/10753005/.

The original cl also includes abstraction of BitReader class used by H264Parser. It includes bugs that break the H264Parser.

In this cl I removed the abstraction and make the BitReader used by H264Parser independent to the one used by esds parser because of:

1. The original cl introduce bugs.
2. Even if we fix the bugs, we may not be able to make the generalized class as fast as the old one while keeping the abstraction.
3. The H264 bit stream use very special syntax on escaping and trailing zero bits, which might not be a good candidate for abstraction.

BUG=134445
TEST=BitReaderTest, AACTest


Review URL: https://chromiumcodereview.appspot.com/10780026

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@147511 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 57 insertions, 0 deletions

diff --git a/media/mp4/es_descriptor.h b/media/mp4/es_descriptor.h
new file mode 100644
index 0000000..daddbc0
--- /dev/null
+++ b/media/mp4/es_descriptor.h
@@ -0,0 +1,57 @@
+// 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.
+
+#ifndef MEDIA_MP4_ES_DESCRIPTOR_H_
+#define MEDIA_MP4_ES_DESCRIPTOR_H_
+
+#include <vector>
+
+#include "base/basictypes.h"
+#include "media/base/media_export.h"
+
+namespace media {
+
+class BitReader;
+
+namespace mp4 {
+
+// The following values are extracted from ISO 14496 Part 1 Table 5 -
+// objectTypeIndication Values. Only values currently in use are included.
+enum ObjectType {
+  kForbidden = 0,
+  kISO_14496_3 = 0x40  // MPEG4 AAC
+};
+
+// This class parse object type and decoder specific information from an
+// elementary stream descriptor, which is usually contained in an esds box.
+// Please refer to ISO 14496 Part 1 7.2.6.5 for more details.
+class MEDIA_EXPORT ESDescriptor {
+ public:
+  ESDescriptor();
+  ~ESDescriptor();
+
+  bool Parse(const std::vector<uint8>& data);
+
+  uint8 object_type() const;
+  const std::vector<uint8>& decoder_specific_info() const;
+
+ private:
+  enum Tag {
+    kESDescrTag = 0x03,
+    kDecoderConfigDescrTag = 0x04,
+    kDecoderSpecificInfoTag = 0x05
+  };
+
+  bool ParseDecoderConfigDescriptor(BitReader* reader);
+  bool ParseDecoderSpecificInfo(BitReader* reader);
+
+  uint8 object_type_;
+  std::vector<uint8> decoder_specific_info_;
+};
+
+}  // namespace mp4
+
+}  // namespace media
+
+#endif  // MEDIA_MP4_ES_DESCRIPTOR_H_