tjpgd.h

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/*----------------------------------------------------------------------------/
/ TJpgDec - Tiny JPEG Decompressor R0.03 include file         (C)ChaN, 2021
/----------------------------------------------------------------------------*/
#ifndef DEF_TJPGDEC
#define DEF_TJPGDEC
 
#ifdef __cplusplus
extern "C" {
#endif
 
#include "tjpgdcnf.h"
#include <string.h>
 
#if defined(_WIN32) /* VC++ or some compiler without stdint.h */
typedef unsigned char uint8_t;
typedef unsigned short  uint16_t;
typedef short     int16_t;
typedef unsigned long uint32_t;
typedef long      int32_t;
#else       /* Embedded platform */
#include <stdint.h>
#endif
 
#if JD_FASTDECODE >= 1
typedef int16_t jd_yuv_t;
#else
typedef uint8_t jd_yuv_t;
#endif
 
 
/* Error code */
typedef enum {
  JDR_OK = 0, /* 0: Succeeded */
  JDR_INTR, /* 1: Interrupted by output function */ 
  JDR_INP,  /* 2: Device error or wrong termination of input stream */
  JDR_MEM1, /* 3: Insufficient memory pool for the image */
  JDR_MEM2, /* 4: Insufficient stream input buffer */
  JDR_PAR,  /* 5: Parameter error */
  JDR_FMT1, /* 6: Data format error (may be broken data) */
  JDR_FMT2, /* 7: Right format but not supported */
  JDR_FMT3  /* 8: Not supported JPEG standard */
} JRESULT;
 
 
 
/* Rectangular region in the output image */
typedef struct {
  uint16_t left;    /* Left end */
  uint16_t right;   /* Right end */
  uint16_t top;   /* Top end */
  uint16_t bottom;  /* Bottom end */
} JRECT;
 
 
 
/* Decompressor object structure */
typedef struct JDEC JDEC;
struct JDEC {
  size_t dctr;        /* Number of bytes available in the input buffer */
  uint8_t* dptr;        /* Current data read ptr */
  uint8_t* inbuf;       /* Bit stream input buffer */
  uint8_t dbit;       /* Number of bits availavble in wreg or reading bit mask */
  uint8_t scale;        /* Output scaling ratio */
  uint8_t msx, msy;     /* MCU size in unit of block (width, height) */
  uint8_t qtid[3];      /* Quantization table ID of each component, Y, Cb, Cr */
  uint8_t ncomp;        /* Number of color components 1:grayscale, 3:color */
  int16_t dcv[3];       /* Previous DC element of each component */
  uint16_t nrst;        /* Restart inverval */
  uint16_t width, height;   /* Size of the input image (pixel) */
  uint8_t* huffbits[2][2];  /* Huffman bit distribution tables [id][dcac] */
  uint16_t* huffcode[2][2]; /* Huffman code word tables [id][dcac] */
  uint8_t* huffdata[2][2];  /* Huffman decoded data tables [id][dcac] */
  int32_t* qttbl[4];      /* Dequantizer tables [id] */
#if JD_FASTDECODE >= 1
  uint32_t wreg;        /* Working shift register */
  uint8_t marker;       /* Detected marker (0:None) */
#if JD_FASTDECODE == 2
  uint8_t longofs[2][2];    /* Table offset of long code [id][dcac] */
  uint16_t* hufflut_ac[2];  /* Fast huffman decode tables for AC short code [id] */
  uint8_t* hufflut_dc[2];   /* Fast huffman decode tables for DC short code [id] */
#endif
#endif
  void* workbuf;        /* Working buffer for IDCT and RGB output */
  jd_yuv_t* mcubuf;     /* Working buffer for the MCU */
  void* pool;         /* Pointer to available memory pool */
  size_t sz_pool;       /* Size of momory pool (bytes available) */
  size_t (*infunc)(JDEC*, uint8_t*, size_t);  /* Pointer to jpeg stream input function */
  void* device;       /* Pointer to I/O device identifiler for the session */
};
 
 
 
/* TJpgDec API functions */
JRESULT jd_prepare (JDEC* jd, size_t (*infunc)(JDEC*,uint8_t*,size_t), void* pool, size_t sz_pool, void* dev);
JRESULT jd_decomp (JDEC* jd, int (*outfunc)(JDEC*,void*,JRECT*), uint8_t scale);
 
 
#ifdef __cplusplus
}
#endif
 
#endif /* _TJPGDEC */