shaka-packager/media/mp4/es_descriptor.h

63 lines
1.6 KiB
C++

// 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
kISO_13818_7_AAC_LC = 0x67, // MPEG2 AAC-LC
kEAC3 = 0xa6 // Dolby Digital Plus
};
// 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:
// Utility function to check if the given object type is AAC.
static bool IsAAC(uint8 object_type);
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_