util.h

音频编码

/*
 *	lame utility library include file
 *
 *	Copyright (c) 1999 Albert L Faber
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Library General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library 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
 * Library General Public License for more details.
 *
 * You should have received a copy of the GNU Library General Public
 * License along with this library; if not, write to the
 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 * Boston, MA 02111-1307, USA.
 */

#ifndef LAME_UTIL_H
#define LAME_UTIL_H

/***********************************************************************
*
*  Global Include Files
*
***********************************************************************/
#include "machine.h"
#include "encoder.h"
#include "lame.h"
#include "lame_global_flags.h"
#include "lame-analysis.h"
#include "id3tag.h"
#include "gain_analysis.h"

#if HAVE_INTTYPES_H
# include <inttypes.h>
#else
# if HAVE_STDINT_H
#  include <stdint.h>
# endif
#endif

#ifdef __cplusplus
extern  "C" {
#endif

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

#ifndef FALSE
#define         FALSE                   0
#endif

#ifndef TRUE
#define         TRUE                    (!FALSE)
#endif

#ifdef UINT_MAX
# define         MAX_U_32_NUM            UINT_MAX
#else
# define         MAX_U_32_NUM            0xFFFFFFFF
#endif

#ifndef PI
# ifdef M_PI
#  define       PI                      M_PI
# else
#  define       PI                      3.14159265358979323846
# endif
#endif


#ifdef M_LN2
# define        LOG2                    M_LN2
#else
# define        LOG2                    0.69314718055994530942
#endif

#ifdef M_LN10
# define        LOG10                   M_LN10
#else
# define        LOG10                   2.30258509299404568402
#endif


#ifdef M_SQRT2
# define        SQRT2                   M_SQRT2
#else
# define        SQRT2                   1.41421356237309504880
#endif


#define         HAN_SIZE                512
#define         CRC16_POLYNOMIAL        0x8005
#define MAX_BITS 4095

/* "bit_stream.h" Definitions */
#define         BUFFER_SIZE     LAME_MAXMP3BUFFER

#define         Min(A, B)       ((A) < (B) ? (A) : (B))
#define         Max(A, B)       ((A) > (B) ? (A) : (B))

/* log/log10 approximations */
#ifdef USE_FAST_LOG
#define         FAST_LOG10(x)       (fast_log2(x)*(LOG2/LOG10))
#define         FAST_LOG(x)         (fast_log2(x)*LOG2)
#define         FAST_LOG10_X(x,y)   (fast_log2(x)*(LOG2/LOG10*(y)))
#define         FAST_LOG_X(x,y)     (fast_log2(x)*(LOG2*(y)))
#else
#define         FAST_LOG10(x)       log10(x)
#define         FAST_LOG(x)         log(x)
#define         FAST_LOG10_X(x,y)   (log10(x)*(y))
#define         FAST_LOG_X(x,y)     (log(x)*(y))
#endif




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



    /* "bit_stream.h" Type Definitions */

    typedef struct bit_stream_struc {
        unsigned char *buf;  /* bit stream buffer */
        int     buf_size;    /* size of buffer (in number of bytes) */
        int     totbit;      /* bit counter of bit stream */
        int     buf_byte_idx; /* pointer to top byte in buffer */
        int     buf_bit_idx; /* pointer to top bit of top byte in buffer */

        /* format of file in rd mode (BINARY/ASCII) */
    } Bit_stream_struc;

#include "l3side.h"


    /* variables used for --nspsytune */
    typedef struct {
        /* variables for nspsytune */
        FLOAT   last_en_subshort[4][9];
        int     last_attacks[4];
        FLOAT   pefirbuf[19];
        FLOAT   longfact[SBMAX_l];
        FLOAT   shortfact[SBMAX_s];

        /* short block tuning */
        FLOAT   attackthre;
        FLOAT   attackthre_s;

        /* variables for nspsytune2 */
        FILE   *pass1fp;
    } nsPsy_t;


    typedef struct {
        int     sum;         /* what we have seen so far */
        int     seen;        /* how many frames we have seen in this chunk */
        int     want;        /* how many frames we want to collect into one chunk */
        int     pos;         /* actual position in our bag */
        int     size;        /* size of our bag */
        int    *bag;         /* pointer to our bag */
    } VBR_seek_info_t;


    /**
     *  ATH related stuff, if something new ATH related has to be added,
     *  please plugg it here into the ATH_t struct
     */
    typedef struct {
        int     use_adjust;  /* method for the auto adjustment  */
        FLOAT   aa_sensitivity_p; /* factor for tuning the (sample power)
                                     point below which adaptive threshold
                                     of hearing adjustment occurs */
        FLOAT   adjust;      /* lowering based on peak volume, 1 = no lowering */
        FLOAT   adjust_limit; /* limit for dynamic ATH adjust */
        FLOAT   decay;       /* determined to lower x dB each second */
        FLOAT   floor;       /* lowest ATH value */
        FLOAT   l[SBMAX_l];  /* ATH for sfbs in long blocks */
        FLOAT   s[SBMAX_s];  /* ATH for sfbs in short blocks */
        FLOAT   psfb21[PSFB21]; /* ATH for partitionned sfb21 in long blocks */
        FLOAT   psfb12[PSFB12]; /* ATH for partitionned sfb12 in short blocks */
        FLOAT   cb[CBANDS];  /* ATH for convolution bands */
        FLOAT   eql_w[BLKSIZE / 2]; /* equal loudness weights (based on ATH) */
    } ATH_t;

    /**
     *  PSY Model related stuff
     */
    typedef struct {
        FLOAT   mask_adjust; /* the dbQ stuff */
        FLOAT   mask_adjust_short; /* the dbQ stuff */
        int     tonalityPatch; /* temporaly needed by VBR */
        FLOAT   cwlimit;
        FLOAT   prvTonRed[CBANDS];
    } PSY_t;


#define MAX_CHANNELS  2





    struct lame_internal_flags {

  /********************************************************************
   * internal variables NOT set by calling program, and should not be *
   * modified by the calling program                                  *
   ********************************************************************/

        /*  
         * Some remarks to the Class_ID field:
         * The Class ID is an Identifier for a pointer to this struct.
         * It is very unlikely that a pointer to lame_global_flags has the same 32 bits 
         * in it's structure (large and other special properties, for instance prime).
         *
         * To test that the structure is right and initialized, use:
         *     if ( gfc -> Class_ID == LAME_ID ) ...
         * Other remark:
         *     If you set a flag to 0 for uninit data and 1 for init data, the right test
         *     should be "if (flag == 1)" and NOT "if (flag)". Unintended modification
         *     of this element will be otherwise misinterpreted as an init.
         */
#  define  LAME_ID   0xFFF88E3B
        unsigned long Class_ID;

        int     lame_encode_frame_init;
        int     iteration_init_init;
        int     fill_buffer_resample_init;

#ifndef  MFSIZE
# define MFSIZE  ( 3*1152 + ENCDELAY - MDCTDELAY )
#endif
        sample_t mfbuf[2][MFSIZE];


        struct {
            void    (*msgf) (const char *format, va_list ap);
            void    (*debugf) (const char *format, va_list ap);
            void    (*errorf) (const char *format, va_list ap);
        } report;

        int     mode_gr;     /* granules per frame */
        int     channels_in; /* number of channels in the input data stream (PCM or decoded PCM) */
        int     channels_out; /* number of channels in the output data stream (not used for decoding) */
        FLOAT   resample_ratio; /* input_samp_rate/output_samp_rate */

        int     mf_samples_to_encode;
        int     mf_size;
        int     VBR_min_bitrate; /* min bitrate index */
        int     VBR_max_bitrate; /* max bitrate index */
        int     bitrate_index;
        int     samplerate_index;
        int     mode_ext;


        /* lowpass and highpass filter control */
        FLOAT   lowpass1, lowpass2; /* normalized frequency bounds of passband */
        FLOAT   highpass1, highpass2; /* normalized frequency bounds of passband */

        int     filter_type; /* 0=polyphase filter, 1= FIR filter 2=MDCT filter(bad) */
        int     quantization; /* 0 = ISO formual,  1=best amplitude */
        int     noise_shaping; /* 0 = none 
                                  1 = ISO AAC model
                                  2 = allow scalefac_select=1