encoder.h

来自「MPEG-4编解码的实现(包括MPEG4视音频编解码)」· C头文件 代码 · 共 79 行

#ifndef ENCODER_DOT_H
#define ENCODER_DOT_H
/***********************************************************************
*
*  encoder and decoder delays
*
***********************************************************************/
/* 
layerIII enc->dec delay:  1056    (observed)
layerII  enc->dec dealy:   480    (observed)


polyphase 256-16             (dec or enc)        = 240
mdct      256+32  (9*32)     (dec or enc)        = 288
total:    512+16

*/



/* ENCDELAY  The encoder delay.  

   Minimum allowed is MDCTDELAY (see below)
   
   The first 96 samples will be attenuated, so using a value
   less than 96 will result in lost data in the first 96-ENCDELAY
   samples. 

   suggested: 800
   set to 1160 to sync with FhG.
*/
#define ENCDELAY 800




/* delay of the MDCT used in mdct.c */
/* original ISO routiens had a delay of 528!  Takehiro's routines: */
#define MDCTDELAY 48  
#define FFTOFFSET (224+MDCTDELAY)

/*
Most decoders, including the one we use,  have a delay of 528 samples.  
*/
#define DECDELAY 528


/* number of subbands */
#define         SBLIMIT                 32

/* parition bands bands */
#define CBANDS          63

/* number of critical bands/scale factor bands where masking is computed*/
#define SBPSY_l 21
#define SBPSY_s 12

/* total number of scalefactor bands encoded */
#define SBMAX_l 22
#define SBMAX_s 13



/* FFT sizes */
#define BLKSIZE         1024
#define HBLKSIZE        513
#define BLKSIZE_s 256
#define HBLKSIZE_s 129


/* #define switch_pe        1800 */
#define NORM_TYPE       0
#define START_TYPE      1
#define SHORT_TYPE      2
#define STOP_TYPE       3


#endif