mp3_common.h

本程序为ST公司开发的源代码

/*
 * $Copyright: 
 * ----------------------------------------------------------------
 * This confidential and proprietary software may be used only as
 * authorised by a licensing agreement from ARM Limited
 *   (C) COPYRIGHT 2001,2002,2003 ARM Limited
 *       ALL RIGHTS RESERVED
 * The entire notice above must be reproduced on all authorised
 * copies and copies may only be made to the extent permitted
 * by a licensing agreement from ARM Limited.
 * ----------------------------------------------------------------
 * File:     common.h,v
 * Revision: 1.29
 * ----------------------------------------------------------------
 * $
 *
 * ISO MPEG Audio Subgroup Software Simulation Group (1996)
 * ISO 13818-3 MPEG-2 Audio Decoder - Lower Sampling Frequency Extension
 *
 */


#ifndef COMMON_H
#define COMMON_H


#include "mp3_options_c.h"
#include "audiodec.h"


/*
 * Define the XP bandwidth reduction control type.
 */
typedef enum tagCutoffMode 
{
	eNormal,
	eReduced,
	eTest
} tCutoffMode;


/*
 * Define the sample rate type.
 */
typedef enum tagSampleRate
{
	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
} tSampleRate ;

typedef	struct	tagMPEGHeader   tMPEGHeader ;
typedef	tMPEGHeader            *ptMPEGHeader ;

struct tagMPEGHeader
{
	tSampleRate	sample_rate ;
        unsigned int    samplesperchannel;
	unsigned int    numchans;
	unsigned int	packed_info;
	unsigned int	bits_required;
	unsigned int	free_format;
} ;

/***********************************************************************
*
*  Global Include Files
*
***********************************************************************/

#include        <stdio.h>
#include        <string.h>


/***********************************************************************
*
*  Global Definitions
*
***********************************************************************/

/* General Definitions */

#define		LAY1	3
#define		LAY2	2
#define		LAY3	1


//#define         FALSE                   0
//#define         TRUE                    1

#define         MONO                    1
#define         STEREO                  2
#define         SBLIMIT                 32
#define         SSLIMIT                 18

#define         GRANULE_SAMPLES_PER_CH  576 /* Layer III */
#define         MPEG1_NUM_GRANULES      2   /* MPEG-1     : number of granules (layer III) */
#define         MPEG2_LSF_NUM_GRANULES  1   /* MPEG-2 LSF : number of granules (layer III) */
#define         MAX_NUM_GRANULES        2   /* maximum number of granules (layer III) */
#define         MAX_NUM_CHANNELS        2
#define         FFT_SIZE                1024
#define         HAN_SIZE                (512+15)
#define         SCALE_BLOCK             12
#define         SCALE_RANGE             64
#define         MIN_OUTPUT_SAMPLES      96
#define         MAX_LONG_SCALEFACTORS   23
#define         MAX_SHORT_SCALEFACTORS  14
/* MPEG Header Definitions - ID Bit Values */
#define         MPEG_AUDIO_ID           1

#define		MPEG_VERSION_LSF_BIT	1
#define		MPEG_VERSION_2_5_BIT	2

/* MPEG Header Definitions - Mode Values */

#define         MPG_MD_STEREO           0
#define         MPG_MD_JOINT_STEREO     1
#define         MPG_MD_DUAL_CHANNEL     2
#define         MPG_MD_MONO             3

/* Mode Extension */

#define         MPG_MD_LR_LR             0
#define         MPG_MD_LR_I              1
#define         MPG_MD_MS_LR             2
#define         MPG_MD_MS_I              3




#define         ALIGNING        8
#define         BUFFER_SIZE     4096

//#define         MIN(A, B)       ((A) < (B) ? (A) : (B))
#define         MAX(A, B)       ((A) > (B) ? (A) : (B))

/***********************************************************************
*
*  Global Type Definitions
*
***********************************************************************/

/* Header Information Structure */

typedef struct {         /* do not reorder elements of this */
    char version;        /* structure--hardwired into       */
    char rlay;           /* decode_packed_info()            */
    char error_protection;
    char bitrate_index;
    char sampling_frequency;
    char padding;
    char mode;
    char mode_ext;
} layer;

/* Parent Structure Interpreting some Frame Parameters in Header */

typedef struct {
    layer       header;        /* raw header information */

    char        stereo;         /* 1 for mono, 2 for stereo */

#if INCLUDE_LAYER==LAYER1 || INCLUDE_LAYER==LAYER2
    char        jsbound;        /* first band of joint stereo coding */
#endif
    short       samples_per_channel;
    int         bytes_required;
} frame_params;


/* "bit_stream.h" Type Definitions */

/* WARNING: This structure is hardwired into the optimized ARM getbits functions */
/* If you change the order here, you will need to keep the assembler consistent. */

typedef struct  bit_stream_struc {
    int         hold_reg;       /* 32-bit bit stream holding register */
    int         buf_bit_idx;    /* pointer to top bit of top byte in buffer */
    unsigned char *buf_ptr;     /* pointer within buffer (ARM code only) */
} Bit_stream_struc;

/* Layer III side information. */

#if INCLUDE_LAYER==LAYER3

#define MPEG_MISC0_LOG_PREFLAG            2
#define MPEG_MISC0_LOG_SCALEFAC_SCALE     1
#define MPEG_MISC0_LOG_COUNT1TABLE_SELECT 0

#define MPEG_MISC0_PREFLAG            0x04
#define MPEG_MISC0_SCALEFAC_SCALE     0x02
#define MPEG_MISC0_COUNT1TABLE_SELECT 0x01


typedef struct gr_info_s {
	unsigned short part2_3_length;          /* 12 bits */
	unsigned short big_values;              /* 9 bits */
	unsigned short scalefac_compress;       /* MPEG-1: 4 bits, MPEG-2: 9 bits */
	unsigned char  global_gain;             /* 8 bits */
	unsigned char  block_type;              /* 2 bits */
	unsigned char  mixed_block_flag;        /* 1 bit */
	unsigned char pad0;
	unsigned short table_sel;         	/* 15 bits */
	unsigned short subblk_gain;             /* 9 bits */
	unsigned char  region0_count;           /* 4 bits */
	unsigned char  region1_count;           /* 3 bits */
	unsigned char  misc0;			/* 3 bits (preflag+scalefac_scale+count1table_select) */
	unsigned char pad1;
	unsigned short pad2;
		} my_gr_info;

typedef struct {
	unsigned short main_data_begin;   /* MPEG-1: 9 bits, MPEG-1: 8 bits           */
	unsigned char private_bits_ignore;       /* MPEG-2: 5 or 3 bits, MPEG-2: 1 or 2 bits */
		unsigned char pad2;
			struct {
                unsigned char scfsi3;
                unsigned char pad2;
                unsigned char pad3;
                unsigned char pad4;
		struct gr_info_s gr[MAX_NUM_GRANULES];
		} ch[MAX_NUM_CHANNELS];
	} III_side_info_t;

/* Layer III scale factors. */

/*
 * Scalefactor value type.
 *
 * The type III_scalefac_1 holds the scalefactor data for a single
 * channel.
 *
 * The format is:
 *
 *  long blocks (MPEG-1)   - values 0..20 are the 21 scalefactor values (including the
 *                           final zero value)
 *  long blocks (MPEG-2)   - values 0..21 are the 22 scalefactor values (including the
 *                           final zero value)
 *  short blocks (MPEG-1)  - values 0..35 are the 12x3 scalefactor values
 *                           arranged in order [sfbnum*3 + win]
 *                           (including last 3 zero values)
 *  short blocks (MPEG-2)  - values 0..38 are the 13x3 scalefactor values
 *                           arranged in order [sfbnum*3 + win]
 *                           (including last 3 zero values)
 *  mixed blocks (MPEG-1)  - values 0..7 are the 8 long scalefactor values
 *                           values 8..34 are the 9x3 short scalefactor values
 *                           (including last 3 zero values)
 *  mixed blocks (MPEG-2)  - values 0..5 are the 6 long scalefactor values
 *                           values 6..35 are the 10x3 short scalefactor values
 *                           (including last 3 zero values)
 */

typedef struct {
        char z[40];
	} III_scalefac_1; 

#endif /* LAYER3 */

 /*
  * Overlap reorder input and output buffers.
  *
  * This assumes that channel 0 is decoded first (which it is)
  * because the reorder output overlays channel 0.
  *
  * Maximum overlap depends on properties of the reorder function
  * which depends on the sampling frequency and MPEG version. The
  * worst case is 48kHz whith a maximum acceptable overlap of 448
  * samples. This saves 1.75k.
  * 
  */

#define OVERLAP_REORDER 448


#if INCLUDE_LAYER==LAYER1
typedef struct
{
    // Layer I dequantisation uses the same code as layer II, which is coded in triplets.
    // Hence the size of the least-significant dimension is 3.
    int  arm_sample_out[SBLIMIT * MAX_NUM_CHANNELS][3]; 
}   LayerI_Scratch;

typedef struct
{
    unsigned char bit_alloc[SBLIMIT * MAX_NUM_CHANNELS];
    unsigned short scale_index[SBLIMIT * MAX_NUM_CHANNELS];
    char     bit_position;
}   LayerI_State;
#endif

#if INCLUDE_LAYER==LAYER2
typedef struct
{
    const char *bs_beginCRC; 
    const char *bs_endCRC; 
    unsigned int bs_endCRC_bitidx;
}   LayerII_Scratch;


typedef struct
{
    char     tab_num;
    char     sblimit;
    char     prev_sblimit;
    char     bit_position;
    char     block_i;
    char     padding[3];
    unsigned char bit_alloc[SBLIMIT+2][MAX_NUM_CHANNELS];
    unsigned short scale_index[SBLIMIT][MAX_NUM_CHANNELS][3]; // coded in triplets
    int      arm_sample_out[SBLIMIT * MAX_NUM_CHANNELS][3]; // coded in triplets
}   LayerII_State;
#endif

#if INCLUDE_LAYER==LAYER3
typedef struct
{
    III_scalefac_1   III_scalefac1[2];
    III_side_info_t  III_side_info;
    int     inre_buf[GRANULE_SAMPLES_PER_CH-OVERLAP_REORDER + GRANULE_SAMPLES_PER_CH*2];
}   LayerIII_Scratch;

typedef struct
{
    unsigned int     offset;
    unsigned int     buf_byte_idx;