theora_codec_info.h

linux下的一款播放器

/* ***** BEGIN LICENSE BLOCK *****
 * Source last modified: $Id: theora_codec_info.h,v 1.2.4.1 2004/11/24 18:02:52 acolwell Exp $
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 * Portions Copyright (c) 1995-2004 RealNetworks, Inc. All Rights Reserved.
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 * The contents of this file, and the files included with this file,
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 * the file under the current version of the RealNetworks Community
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 * will apply. You may also obtain the license terms directly from
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 * ***** END LICENSE BLOCK ***** */
#ifndef THEORA_CODEC_INFO_H
#define THEORA_CODEC_INFO_H

#include "codec_info.h"

class CTheoraCodecInfo : public COggCodecInfo
{
public:
    static COggCodecInfo* Build(ogg_packet* pPkt);
    
    virtual ~CTheoraCodecInfo();

    // COggCodecInfo methods
    virtual HX_RESULT OnPacket(ogg_packet* pPkt);

    virtual OggCodecType Type() const;
    virtual BOOL HaveHeaders() const;
    virtual BOOL HaveBaseGranulePos() const;
    virtual BOOL AllowPacketOutError() const;

    virtual ogg_int64_t CurrentGranulePos() const;
    virtual HX_RESULT SetCurrentGranulePos(ogg_int64_t pos);
    virtual ogg_int64_t GranulePosDropped() const;
    virtual ogg_int64_t GranulePosDifference(ogg_int64_t a, 
                                             ogg_int64_t b) const;

    virtual BOOL IsHeader(ogg_packet* pPkt) const;
    virtual BOOL IsCommentHeader(ogg_packet* pPkt) const;
    virtual ogg_packet* CreateBlankCommentPacket() const;

    virtual HX_RESULT GetTimestamp(ogg_int64_t granulePos, 
                                   COggTimestamp& timestamp) const;

    virtual HX_RESULT GetBaseTimestamp(COggTimestamp& timestamp) const;
    virtual HX_RESULT SetBaseTimestamp(const COggTimestamp& timestamp);
    virtual HX_RESULT SetStartTimestamp(const COggTimestamp& timestamp);

    virtual COggCodecInfo* Clone() const;

private:
    typedef enum {
        Start,
        NeedComment,
        NeedCodebook,
        NeedFirstDataPkt,
        NeedBaseTime,
        Ready
    } State;

    CTheoraCodecInfo();
    HX_RESULT copy(const CTheoraCodecInfo& rhs);

    void changeState(State newState);
    HX_RESULT handleIdentHdr(ogg_packet* pPkt);
    HX_RESULT updatePosition(ogg_packet* pPkt);
    
    UINT32 gcd(UINT32 a, UINT32 b);
    ogg_int64_t granuleToFrames(ogg_int64_t pos) const;
    ogg_int64_t framesToGranulePos(ogg_int64_t frames) const;

    static BOOL isTheoraHeader(ogg_packet* pPkt);

    State m_state;
    UINT32 m_uFPSNum;
    UINT32 m_uFPSDenom;
    UINT32 m_uBitrate;    
    UINT8  m_uKeyFrameShift;
    UINT8* m_pIdentBuf;
    UINT32 m_uIdentBufSize;
    BOOL m_bFirstPkt;
    ogg_int64_t m_currentPos;
    ogg_int64_t m_basePos;
    ogg_int64_t m_dropped;

    COggTimestamp m_startTimestamp;
    
    static const unsigned char zm_blankComment[];
};
#endif /* THEORA_CODEC_INFO_H */