mp2dec.h

瑞星微公司RK27XX系列芯片的SDK开发包

#ifndef _MP2AUDIO_
#define _MP2AUDIO_

#define MP2_MAX_PCM_LENGTH 1152
#define MP2_MAX_BITS_REQUIRED   11520
#define MP2_NINFOBITS  32


#define FILE_MP2_MODE 0
#define DAB_MP2_MODE 1

#include "MP2DEC_instance.h"
/*
 * Define the sample rate type.
 */

typedef enum tagMP2SampleRate
{
    SR_11_025kHz,
    SR_12kHz,
    SR_8kHz,
    SR_ReservedMPEG2_5,
    SR_22_05kHz,
    SR_24kHz,
    SR_16kHz,
    SR_ReservedLSF,
    SR_44_1kHz,
    SR_48kHz,
    SR_32kHz,
    SR_Reserved
} tMP2SampleRate ;


typedef struct tagMP2Bitstream   tMP2Bitstream ;
typedef tMP2Bitstream            *ptMP2Bitstream ;

struct tagMP2Bitstream
{
    unsigned int   *bufptr;
    unsigned int    bitidx;
} ;



typedef struct tagMP2Header   tMP2Header ;
typedef tMP2Header            *ptMP2Header ;

struct tagMP2Header
{
    tMP2SampleRate sample_rate ;
    unsigned int    samplesperchannel;
    unsigned int    numchans;
    unsigned int packed_info;
    unsigned int bits_required;
    unsigned int free_format;
} ;

typedef enum tagMP2Status
{
    eNoErr,
    eNoSyncword,
    eCRCError,
    eBrokenFrame,
    eEndOfBitstream,
    eDataOverflow,
    eCantAllocateBuffer,
    eUnsupportedLayer,
    eFrameDiscarded,
    eReservedSamplingFrequency,
    eForbiddenBitRate,
    eWrongMPEGBuild
} tMP2Status ;



/*
 *       InitMP2Audio
 *       ============
 *
 * Description
 * -----------
 * Initializes the MPEG audio decoder.
 * Call this function before using any other decoder functions.
 *
 * Syntax
 * ------
 *   void InitMP2Audio( tMP2Instance *inst, unsigned char *in )
 *
 * where:
 *
 *   inst        pointer to instance data for the decoder.
 *   in          pointer to Input buffer
 */

void RKInitMP2Audio(tMP2Instance *inst , unsigned char *in);


/*
 *       MP2DECSearchForSyncword
 *       ====================
 *
 * Description
 * -----------
 * This function searches for the syncword and decodes a frame of samples from the MP2 stream.
 *
 * Syntax
 * ------
 *  tMP2Status MP2DECSearchForSyncword(tMP2Bitstream *bs,tMP2Header *hdr, unsigned short ValidCount);
 *
 * where:
 *
 *   bs             pointer to the structure that points to the incoming bitstream.
 *   hdr            pointer to the structure that points to the header information.
 *   ValidCount  number of new valid bits
 *   UsedCount      number of used bit in function (return value)
 *
 * Return Value
 * ------------
 *
 *   tMP2Status  function's return status:
 *
 *   eNoErr                      Frame decoded ok
 *   eNoSyncword                 No syncronization word
 *   eUnsupportedLayer           Unsupported or illegal ('00') MPEG audio layer
 *   eReservedSamplingFrequency  Undefined sampling frequency ('11')
 *   eForbiddenBitRate           Illegal bit rate ('1111')
 */

tMP2Status RKMP2DECSearchForSyncword(tMP2Bitstream *bs, tMP2Header *hdr, unsigned short ValidCount, unsigned int *UsedCount);



/*
 *       MP2DecodeData
 *       =============
 *
 * Description
 * -----------
 * This function decodes a frame of samples from the MP3 stream.
 *
 * Syntax
 * ------
 *   tMP2Status MP2DecodeData( short *left, short *right, tMP2Bitstream *bs, int mode ) ;
 *
 * where:
 *
 *   left     pointer to output buffer for left-channel PCM.
 *   right    pointer to output buffer for right-channel PCM.
 *   bs       pointer to the structure that points to the incoming bitstream.
 *   mode     select scalefactor crc check mode
 *
 * Return Value
 * ------------
 *
 *   tMP2Status  function's return status:
 *
 *   eNoErr                      Frame decoded ok
 *   eCRCError                   CRC error failed
 *   eBrokenFrame                Side information is inconsistent
 *   eFrameDiscarded             Insufficient main data to decode the frame
 *
 */
tMP2Status RKMP2DecodeData(short *left, short *right, tMP2Bitstream *bs, int mode);
tMP2Status RKMP2DecodeData_DAB(short *left, short *right, tMP2Bitstream *bs, int mode);




typedef void F_MP2DEC0(tMP2Instance *inst , unsigned char *in);
typedef tMP2Status F_MP2DEC1(tMP2Bitstream *bs, tMP2Header *hdr, unsigned short ValidCount, unsigned int *UsedCount);
//typedef tMP2Status F_MP2DEC2( short *left, short *right, tMP2Bitstream *bs, int mode) ;
typedef tMP2Status F_MP2DEC2(short *left, short *right, tMP2Bitstream *bs) ;


extern  F_MP2DEC0 *InitMP2Aud; // = InitMP2Audio;
extern F_MP2DEC1 *MP2SyncHeader; // = MP2DECSearchForSyncword;
extern F_MP2DEC2 *MP2DecData; // = MP2DecodeData;


#endif /* _MPGAUDIO_ */