djpeg.c

jpeg格式到bmp格式的硬件实现

//////////////////////////////////////////////////////////////////////////////
// JPEG僨僐乕僪
// 2005擭10寧26擔 V1.0 
// All Rights Reserved, Copyright (c) Hidemi Ishihara
//////////////////////////////////////////////////////////////////////////////
//
// JPEG傪擖椡偡傞偲Bitmap傪弌椡偟傑偡丅
// 
// % gcc -o djpeg fjpeg.c
// % djpeg 擖椡僼傽僀儖柤丂弌椡僼傽僀儖柤
//////////////////////////////////////////////////////////////////////////////
#include <stdio.h>
#include <stdlib.h>

unsigned int BuffIndex;  // JPEG僨乕僞偺埵抲
unsigned int BuffSize;   // JPEG僨乕僞偺戝偒偝
unsigned int BuffX;      // 夋憸偺墶僒僀僘
unsigned int BuffY;      // 夋憸偺廲僒僀僘
unsigned int BuffBlockX; // MCU偺墶屄悢
unsigned int BuffBlockY; // MCU偺廲屄悢
unsigned char *Buff;     // 怢挿偟偨僨乕僞傪擖傟傞僶僢僼傽

unsigned char  TableDQT[4][64];  // 検巕壔僥乕僽儖
unsigned short TableDHT[4][162]; // 僴僼儅儞僥乕僽儖

unsigned short TableHT[4][16]; // 僴僼儅儞僗僞乕僩僥乕僽儖
unsigned char  TableHN[4][16]; // 僴僼儅儞僗僞乕僩斣崋

unsigned char BitCount = 0; // 埑弅僨乕僞偺撉傒崬傒埵抲
unsigned int LineData;      // 怢挿偵巊偆僨乕僞
unsigned int NextData;      // 怢挿偵巊偆僨乕僞

unsigned int PreData[3]; // DC惉暘梡偺挋傔僶僢僼傽

// 僕僌僓僌僥乕僽儖
int zigzag_table[]={
     0, 1, 8, 16,9, 2, 3,10,
    17,24,32,25,18,11, 4, 5,
    12,19,26,33,40,48,41,34,
    27,20,13, 6, 7,14,21,28,
    35,42,49,56,57,50,43,36,
    29,22,15,23,30,37,44,51,
    58,59,52,45,38,31,39,46,
    53,60,61,54,47,55,62,63,
    0
};

typedef unsigned short WORD;
typedef unsigned long DWORD;
typedef long LONG;

typedef struct tagBITMAPFILEHEADER {
  WORD    bfType;
  DWORD   bfSize;
  WORD    bfReserved1;
  WORD    bfReserved2;
  DWORD   bfOffBits;
} BITMAPFILEHEADER, *PBITMAPFILEHEADER;

typedef struct tagBITMAPINFOHEADER{
  DWORD  biSize;
  LONG   biWidth;
  LONG   biHeight;
  WORD   biPlanes;
  WORD   biBitCount;
  DWORD  biCompression;
  DWORD  biSizeImage;
  LONG   biXPelsPerMeter;
  LONG   biYPelsPerMeter;
  DWORD  biClrUsed;
  DWORD  biClrImportant;
} BITMAPINFOHEADER, *PBITMAPINFOHEADER;

//////////////////////////////////////////////////////////////////////////////
// Bitmap傪弌椡偡傞
// file: 僼傽僀儖柤
// x,y:  夋憸偺僒僀僘
// b:    僶僀僩僇僂儞僩(1僪僢僩曈傝偺僶僀僩悢)
//////////////////////////////////////////////////////////////////////////////
void BmpSave(unsigned char *file,unsigned char *buff,
	     unsigned int x,unsigned int y,unsigned int b){
  BITMAPFILEHEADER lpBf;
  BITMAPINFOHEADER lpBi;
  unsigned char tbuff[4];
  FILE *fp;
  unsigned char str;
  int i,k;

  if((fp = fopen(file,"wb")) == NULL){
    perror(0);
    exit(0);
  }

  // 僼傽僀儖僿僢僟偺愝掕
  tbuff[0] = 'B';
  tbuff[1] = 'M';
  fwrite(tbuff,2,1,fp);
  tbuff[3] = ((14 +40 +x *y *b) >> 24) & 0xff;
  tbuff[2] = ((14 +40 +x *y *b) >> 16) & 0xff;
  tbuff[1] = ((14 +40 +x *y *b) >>  8) & 0xff;
  tbuff[0] = ((14 +40 +x *y *b) >>  0) & 0xff;
  fwrite(tbuff,4,1,fp);
  tbuff[1] = 0;
  tbuff[0] = 0;
  fwrite(tbuff,2,1,fp);
  fwrite(tbuff,2,1,fp);
  tbuff[3] = 0;
  tbuff[2] = 0;
  tbuff[1] = 0;
  tbuff[0] = 54;
  fwrite(tbuff,4,1,fp);

  // 僀儞僼僅儊乕僔儑儞偺愝掕
  lpBi.biSize            = 40;
  lpBi.biWidth           = x;
  lpBi.biHeight          = y;
  lpBi.biPlanes          = 1;
  lpBi.biBitCount        = b*8;
  lpBi.biCompression     = 0;
  lpBi.biSizeImage       = x*y*b;
  lpBi.biXPelsPerMeter   = 300;
  lpBi.biYPelsPerMeter   = 300;
  lpBi.biClrUsed         = 0;
  lpBi.biClrImportant    = 0;
  fwrite(&lpBi,1,40,fp);

  // 忋壓斀揮
  for(k=0;k<y/2;k++){
    for(i=0;i<x*3;i++){
      str = buff[k*x*3+i];
      buff[k*x*3+i] = buff[((y-1)*x*3 -k*x*3) +i];
      buff[((y-1)*x*3-k*x*3) +i] = str;
    }
  }

  fwrite(buff,1,x*y*b,fp);

  fclose(fp);
}

//////////////////////////////////////////////////////////////////////////////
// 1Byte庢摼
unsigned char get_byte(unsigned char *buff){
  if(BuffIndex >= BuffSize) return 0;
  return buff[BuffIndex++];
}
//////////////////////////////////////////////////////////////////////////////
// 2Byte庢摼
unsigned short get_word(unsigned char *buff){
  unsigned char h,l;
  h = get_byte(buff);
  l = get_byte(buff);
  return (h<<8)|l;
}

//////////////////////////////////////////////////////////////////////////////
// 32bit僨乕僞庢摼(怢挿帪偺傒巊梡偡傞)
unsigned int get_data(unsigned char *buff){
  unsigned char str = 0;
  unsigned int data = 0;
  str = get_byte(buff);
  if(str ==0xff) if(get_byte(buff)== 0x00) str = 0xFF; else str = 0x00;
  data = str;
  str = get_byte(buff);
  if(str ==0xff) if(get_byte(buff)== 0x00) str = 0xFF; else str = 0x00;
  data = (data << 8) | str;
  str = get_byte(buff);
  if(str ==0xff) if(get_byte(buff)== 0x00) str = 0xFF; else str = 0x00;
  data = (data << 8) | str;
  str = get_byte(buff);
  if(str ==0xff) if(get_byte(buff)== 0x00) str = 0xFF; else str = 0x00;
  data = (data << 8) | str;
  //printf(" Get Data: %08x\n",data);
  return data;
}

//////////////////////////////////////////////////////////////////////////////
// APP0張棟
void GetAPP0(unsigned char *buff){
  unsigned short data;
  unsigned char str;
  unsigned int i;
  
  data = get_word(buff); // Lp(儗儞僌僗)
  // APP0偼撉傑側偔偰傕偄偄偺偱庢傝崌偊偢儗儞僌僗暘僗僉僢僾偡傞
  for(i=0;i<data-2;i++){
    str = get_byte(buff);
  }
  /*
  str = get_byte(buff);  // 幆暿巕(5暥帤,"JFIF"偲[00])
  str = get_byte(buff);
  str = get_byte(buff);
  str = get_byte(buff);
  str = get_byte(buff);
  data = get_word(buff); // 僶乕僕儑儞
  str = get_byte(buff);  // 夝憸搙偺扨埵
  data = get_word(buff); // 墶曽岦偺夝憸搙
  data = get_word(buff); // 廲曽岦偺夝憸搙
  data = get_word(buff); // 僒儉僱僀儖偺墶僺僋僙儖悢
  data = get_word(buff); // 僒儉僱僀儖偺廲僺僋僙儖悢
  data = get_word(buff); // 僒儉僱僀儖僨乕僞(偁傞応崌偩偗)
  */
}

//////////////////////////////////////////////////////////////////////////////
// DQT張棟
void GetDQT(unsigned char *buff){
  unsigned short data;
  unsigned char str;
  unsigned int i;
  unsigned int tablenum;

  data = get_word(buff);
  str = get_byte(buff); // 僥乕僽儖斣崋
  
  //printf("*** DQT Table %d\n",str);
  for(i=0;i<64;i++){
    TableDQT[str][i] = get_byte(buff);
    //printf(" %2d: %2x\n",i,TableDQT[str][i]);
  }
}

//////////////////////////////////////////////////////////////////////////////
// DHT張棟
void GetDHT(unsigned char *buff){
  unsigned short data;
  unsigned char str;
  unsigned int i;
  unsigned char max,count;
  unsigned short ShiftData = 0x8000,HuffmanData =0x0000;
  unsigned int tablenum;

  data = get_word(buff);
  str = get_byte(buff);

  switch(str){
  case 0x00:
    tablenum = 0x00;
    break;
  case 0x10:
    tablenum = 0x01;
    break;
  case 0x01:
    tablenum = 0x02;
    break;
  case 0x11:
    tablenum = 0x03;
    break;
  }

  //printf("*** DHT Table/Number %d\n",tablenum);
  // 僥乕僽儖傪嶌惉偡傞
  max = 0;
  for(i=0;i<16;i++){
    count = get_byte(buff);
    TableHT[tablenum][i] = HuffmanData;
    TableHN[tablenum][i] = max;
    //printf(" %2d: %4x,%2x\n",i,TableHT[tablenum][i],TableHN[tablenum][i]);
    max = max + count;
    while(!(count==0)){
      HuffmanData += ShiftData;
      count--;
    }
    ShiftData = ShiftData >> 1; // 塃偵1bit僔僼僩偡傞
  }

  //printf("*** DHT Table %d\n",tablenum);
  for(i=0;i<max;i++){
    TableDHT[tablenum][i] = get_byte(buff);
    //printf(" %2d: %2x\n",i,TableDHT[tablenum][i]);
  }
}

//////////////////////////////////////////////////////////////////////////////
// SOF張棟
void GetSOF(unsigned char *buff){
  unsigned short data;
  unsigned char str;
  unsigned int i;
  unsigned char count;

  data = get_word(buff);
  str = get_byte(buff);
  BuffY = get_word(buff); // 夋憸偺墶僒僀僘
  BuffX = get_word(buff); // 夋憸偺廲僒僀僘
  count = get_byte(buff); // 僨乕僞偺僐儞億乕僱儞僩悢
  for(i=0;i<count;i++){
    str = get_byte(buff); // 僐儞億乕僱儞僩斣崋
    str = get_byte(buff); // 僒儞僾儕儞僌斾棪
    str = get_byte(buff); // DQT僥乕僽儖斣崋
  }

  // MCU偺僒僀僘傪嶼弌偡傞
  BuffBlockX = (int)(BuffX /16);
  if(BuffX % 16 >0) BuffBlockX++;
  BuffBlockY = (int)(BuffY /16);
  if(BuffY % 16 >0) BuffBlockY++;
  Buff = (unsigned char*)malloc(BuffBlockY*16*BuffBlockX*16*3);

  //printf(" size : %d x %d,(%d x %d)\n",BuffX,BuffY,BuffBlockX,BuffBlockY);
}

//////////////////////////////////////////////////////////////////////////////
// SOS張棟
void GetSOS(unsigned char *buff){
  unsigned short data;
  unsigned char str;
  unsigned int i;
  unsigned char count;

  data = get_word(buff);
  count = get_byte(buff);
  for(i=0;i<count;i++){
    str = get_byte(buff);
    str = get_byte(buff);
  }
  str = get_byte(buff);
  str = get_byte(buff);
  str = get_byte(buff);
}

//////////////////////////////////////////////////////////////////////////////
// 僴僼儅儞僨僐乕僪亄媡検巕壔亄媡僕僌僓僌
void HuffmanDecode(unsigned char *buff, unsigned char table, int *BlockData){
  unsigned int data;
  unsigned char zero;
  unsigned short code,huffman;
  unsigned char count =0;
  unsigned int BitData;
  unsigned int i;
  unsigned char tabledqt,tabledc,tableac,tablen;
  unsigned char ZeroCount,DataCount;
  int DataCode;

  for(i=0;i<64;i++) BlockData[i] = 0x0; // 僨乕僞偺儕僙僢僩

  // 僥乕僽儖斣崋傪愝掕偡傞
  if(table ==0x00){
    tabledqt =0x00;
    tabledc =0x00;
    tableac =0x01;
  }else if(table ==0x01){
    tabledqt =0x01;
    tabledc  =0x02;
    tableac  =0x03;
  }else{
    tabledqt =0x01;
    tabledc  =0x02;
    tableac  =0x03;
  }

  count = 0; // 擮偺偨傔偵
  while(count <64){
    // 價僢僩僇僂儞僩偺埵抲偑32傪墇偊偨応崌丄怴偨偵僨乕僞傪庢摼偡傞
    if(BitCount >=32){
      LineData = NextData;
      NextData = get_data(buff);
      BitCount -= 32;
    }
    // Huffman僨僐乕僪偱巊梡偡傞僨乕僞偵抲偒姺偊傞
    if(BitCount >0){
      BitData = (LineData << BitCount) | (NextData >> (32 - BitCount));
    }else{
      BitData = LineData;
    }
    //printf(" Haffuman BitData(%2d,%2d): %8x\n",table,count,BitData);

    // 巊梡偡傞僥乕僽儖偺僙儗僋僩
    if(count ==0) tablen = tabledc; else tablen = tableac;
    code = (unsigned short)(BitData >> 16); // 僐乕僪偼16價僢僩巊梡偡傞
    // 僴僼儅儞僐乕僪偑偳偺價僢僩悢偵偄傞偐妱傝弌偡
    for(i=0;i<16;i++) {
      //printf(" Haff hit(%2d:%2d): %8x,%8x\n",table,i,TableHT[tablen][i],code);
      if(TableHT[tablen][i]>code) break;
    }
    i--;

    code    = (unsigned short)(code >> (15 - i)); // 僐乕僪偺壓埵傪懙偊傞
    huffman = (unsigned short)(TableHT[tablen][i] >> (15 - i));

    //printf(" PreUse Dht Number(%2d): %8x,%8x,%8x\n",i,code,huffman,TableHN[tablen][i]);

    // 僴僼儅儞僥乕僽儖偺応強傪嶼弌偡傞
    code = code - huffman + TableHN[tablen][i];

    //printf(" Use Dht Number: %8x\n",code);

    ZeroCount = (TableDHT[tablen][code] >> 4) & 0x0F; // 僛儘儗儞僌僗偺屄悢
    DataCount = (TableDHT[tablen][code]) & 0x0F;      // 懕偔僨乕僞偺價僢僩挿
    //printf(" Dht Table: %8x,%8x\n",ZeroCount,DataCount);
    // 僴僼儅儞僐乕僪傪敳偒丄懕偔僨乕僞傪庢摼偡傞
    DataCode  = (BitData << (i + 1)) >> (16 + (16 - DataCount));
    // 愭摢價僢僩偑"0"偱偁傟偽晧偺僨乕僞丄忋埵價僢僩偵侾傪棫偰偰丄侾傪懌偡
    //if(!(DataCode & (1<<(DataCount-1)))) DataCode=DataCode-(1<<DataCount)+1;