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|
/*****************************************************************
|
| AP4 - AC4 Sync Frame Parser
|
| Copyright 2002-2020 Axiomatic Systems, LLC
|
|
| This file is part of Bento4/AP4 (MP4 Atom Processing Library).
|
| Unless you have obtained Bento4 under a difference license,
| this version of Bento4 is Bento4|GPL.
| Bento4|GPL is free software; you can redistribute it and/or modify
| it under the terms of the GNU General Public License as published by
| the Free Software Foundation; either version 2, or (at your option)
| any later version.
|
| Bento4|GPL is distributed in the hope that it will be useful,
| but WITHOUT ANY WARRANTY; without even the implied warranty of
| MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
| GNU General Public License for more details.
|
| You should have received a copy of the GNU General Public License
| along with Bento4|GPL; see the file COPYING. If not, write to the
| Free Software Foundation, 59 Temple Place - Suite 330, Boston, MA
| 02111-1307, USA.
|
****************************************************************/
#ifndef _AP4_AC4_PARSER_H_
#define _AP4_AC4_PARSER_H_
/*----------------------------------------------------------------------
| includes
+---------------------------------------------------------------------*/
#include "Ap4Types.h"
#include "Ap4BitStream.h"
#include "Ap4Dac4Atom.h"
/*----------------------------------------------------------------------
| constants
+---------------------------------------------------------------------*/
#define AP4_AC4_HEADER_SIZE 7 /* The header size for AC-4 parser, only include (sync word + frame size) */
#define AP4_AC4_MAX_TOC_SIZE 512 /* Ths assumption of max toc size */
#define AP4_AC4_SYNC_WORD 0xAC40 /* 16 sync bits without CRC */
#define AP4_AC4_SYNC_WORD_CRC 0xAC41 /* 16 sync bits with CRC */
/*----------------------------------------------------------------------
| types
+---------------------------------------------------------------------*/
class AP4_Ac4Header {
public:
// constructor
AP4_Ac4Header(const AP4_UI08* bytes, unsigned int size);
// methods
AP4_Result Check();
// AC-4 Sync Frame Inforamtion
AP4_UI32 m_SyncWord;
AP4_UI32 m_HeaderSize;
AP4_UI32 m_FrameSize;
AP4_UI32 m_CrcSize;
// AC-4 Channel Count
AP4_UI32 m_ChannelCount;
// Ac-4 General/High Level TOC Information
AP4_UI32 m_BitstreamVersion;
AP4_UI32 m_SequenceCounter;
AP4_UI32 m_BWaitFrames;
AP4_UI32 m_WaitFrames;
AP4_UI32 m_BrCode;
AP4_UI32 m_FsIndex;
AP4_UI32 m_FrameRateIndex;
AP4_UI32 m_BIframeGlobal;
AP4_UI32 m_BSinglePresentation;
AP4_UI32 m_BMorePresentations;
AP4_UI32 m_NPresentations;
AP4_UI32 m_BPayloadBase;
AP4_UI32 m_PayloadBase;
AP4_UI32 m_BProgramId;
AP4_UI32 m_ShortProgramId;
AP4_UI32 m_BProgramUuidPresent;
AP4_Byte m_ProgramUuid[16];
static bool m_DeprecatedV0;
// AC-4 Presentation Information
AP4_Dac4Atom::Ac4Dsi::PresentationV1 *m_PresentationV1;
// class methods
static bool MatchFixed(AP4_Ac4Header& frame, AP4_Ac4Header& next_frame);
private:
AP4_Result GetPresentationVersionBySGIndex(unsigned int substream_group_index);
AP4_Result GetPresentationIndexBySGIndex (unsigned int substream_group_index);
};
typedef struct {
AP4_UI32 m_HeaderSize;
AP4_UI32 m_FrameSize;
AP4_UI32 m_CRCSize;
AP4_UI32 m_ChannelCount;
AP4_UI32 m_SampleDuration;
AP4_UI32 m_MediaTimeScale;
AP4_UI32 m_Iframe;
AP4_Dac4Atom::Ac4Dsi m_Ac4Dsi;
} AP4_Ac4FrameInfo;
typedef struct {
AP4_BitStream* m_Source;
AP4_Ac4FrameInfo m_Info;
} AP4_Ac4Frame;
class AP4_Ac4Parser {
public:
// constructor and destructor
AP4_Ac4Parser();
virtual ~AP4_Ac4Parser();
// methods
AP4_Result Reset();
AP4_Result Feed(const AP4_UI08* buffer,
AP4_Size* buffer_size,
AP4_Flags flags = 0);
AP4_Result FindFrame(AP4_Ac4Frame& frame);
AP4_Result Skip(AP4_Size size);
AP4_Size GetBytesFree();
AP4_Size GetBytesAvailable();
private:
// methods
AP4_Result FindHeader(AP4_UI08* header);
AP4_UI32 GetSyncFrameSize(AP4_BitReader &bits);
// members
AP4_BitStream m_Bits;
AP4_Cardinal m_FrameCount;
};
#endif // _AP4_AC4_PARSER_H_
|
