jpeglole.c

JPEG压缩和解压程序和一些相关的说明文档 内容比较全

/*This programe is reedited from IJG code by Fujian Shi([e-mail]).
 *This file is used to finish the compression of a gray image by PDCM
 *jpeglole.c ,jcmarker.c ,jarithc.c,jaricom.c , dpredic.c need to combined together.
 */


#include "commondecls.h"

void  *
alloc_one_row(j_compress_ptr cinfo,size_t size_object)
{
  void *buffer_ptr; 
  buffer_ptr=cinfo->buffer[cinfo->buffer_count++]=(void *) 
    malloc(size_object);

  return buffer_ptr;
}

/*arrage several rows buffer,that is a array*/
JSAMPARRAY
alloc_sarray (JDIMENSION samplesperrow, JDIMENSION numrows,j_compress_ptr cinfo)
/* Allocate a 2-D sample array */
{
  JSAMPARRAY result;
  JSAMPROW workspace;
  int currow;

 

  /* Get space for row pointers (small object) */
  result = (JSAMPARRAY) alloc_one_row(cinfo,((size_t) numrows) * SIZEOF(JSAMPROW));

  /* Get the rows themselves (large objects) */
  currow = 0;
  while (currow < numrows) {
    workspace = (JSAMPROW) alloc_one_row(cinfo,((size_t) (samplesperrow)
		  * SIZEOF(JSAMPLE)));
    result[currow++] = workspace;
    
  }

  return result;
}


LOCAL(void)
free_mem(j_compress_ptr cinfo)
{
  int i;
  
  for (i=0;i<cinfo->buffer_count;i++)
   
    free(cinfo->buffer[i]);
  
 }





main(int argc,char *argv[])
{
      j_compress_struct main_cinfo;
      int i,p;
      char c;
      jpeg_destination_mgr main_dest;
      unsigned char fileheader[8];            /*the compact image data include only width and height*/

      j_compress_ptr cinfo=&main_cinfo;
      arith_entropy_encoder entropy;
      jpeg_source_mgr src;

      cinfo->src=&src;
      cinfo->dest=&main_dest;
      cinfo->buffer_count=0;
      cinfo->entropy=&entropy;
      main_cinfo.outbuffer=(JOCTET *) alloc_one_row(cinfo,(size_t) (OUTPUT_BUF_SIZE)); /*sizeof(JOCTET) is 1 */
      main_dest.next_output_byte =cinfo->outbuffer;
      main_dest.free_in_buffer = OUTPUT_BUF_SIZE;
      cinfo->arith_dc_L=1;
      cinfo->first_line=0;
      cinfo->unread_marker=0;
      MEMZERO(cinfo->entropy->dc_stats,160);
      MEMZERO(cinfo->entropy->context_b,1000);
      MEMZERO(cinfo->entropy->val_b,1000);
      MEMZERO(cinfo->pre.N,365*4);
      MEMZERO(cinfo->pre.B,365*4);
      MEMZERO(cinfo->pre.C,365*4);
      cinfo->pre.reset=64;    
      
      cinfo->arith_dc_U=2;
      cinfo->entropy->c = 0;
      cinfo->entropy->a = 0x10000;
      cinfo->entropy->sc = 0;
      cinfo->entropy->zc = 0;
      cinfo->entropy->ct = 0;
      cinfo->entropy->last_val=0;
      cinfo->entropy->context=0;
      cinfo->entropy->buffer = -1;            /* empty */


     if((cinfo->inputfile=fopen(argv[1],"rb"))==NULL){
	printf("The %s can't be opended\n",argv[1]);
	exit(0);
      }
      if((cinfo->outputfile=fopen(argv[2],"wb+"))==NULL){
	printf("The %s can't be created\n",argv[2]);
	exit(0);
      }
      sscanf(argv[3],"%d",&cinfo->pre.near);
      
      #define UCH(x) ((int)(x))
      #define GET_2B(array,offset)  ((unsigned int) UCH(array[offset+1]) + \
			       (((unsigned int) UCH(array[offset])) << 8))
      if (! ReadOK(cinfo->inputfile, fileheader, 6)){
         printf("error when read the head of file");
         exit(0);
      }
      cinfo->image_width = (UINT16) GET_2B(fileheader,2);
      cinfo->image_height = (UINT16) GET_2B(fileheader,4);
      
      cinfo->inbuffer=alloc_sarray((JDIMENSION) (4096),
				  1,cinfo);                /*the inbuffer is a row of image elements now for*
                                                            *one demintion prediction.
                                                            */
      
      src.next_input_byte=cinfo->inbuffer[0];
      src.bytes_in_buffer=0;
      /*create the quality and huff table*/
      /*create_huff (cinfo); It is keeped for later compareration*/
             
    




     /*write the proper file header,for simplisity we only reserve the SOI and EOI symbole*/
      write_file_header (cinfo);
            
      /*prepare for the compresion*/
      /*jpeg_make_c_derived_tbl (cinfo, 1,
       *		      &(cinfo->d_dc_huff_tbl_ptr));
       *jpeg_make_c_derived_tbl (cinfo, 0,
       *		      &(cinfo->d_ac_huff_tbl_ptr));
       */
     /*Enthopy coding and write to the JPEG file*/
      
          
      initial_decoder(cinfo);
     for (i=0;i<(cinfo->image_height);i++){
      
       decode_row(cinfo,i);
     } 
      
      
     /*kill all the buffer and output EOI marker*/
                           /*out put the patial image data*/
     write_file_trailer (cinfo); 
     JFWRITE(cinfo->outputfile, cinfo->outbuffer, 
       (((size_t) (OUTPUT_BUF_SIZE))-cinfo->dest->free_in_buffer));
     
     free_mem(cinfo);
     /*fseek(cinfo->inputfile,-2,2);*/
     p=0;
      while(getc(cinfo->inputfile)!=EOF)	
	    p++;
      printf("the mumber is%d\n",p);
      fclose(cinfo->inputfile);
      fclose(cinfo->outputfile);
}