void jint_process_mcu(jpeg_compress_info *cinfo)
{
//处理每个颜色元件
int cn,tn;
for(cn=0;cn<cinfo->num_comp;cn++)
{
//元件中使用到的变量
DCTBLOCK *dct_table=cinfo->comp[cn].dct_table;
JQUANT_TBL *quant_table=cinfo->quant_table[cinfo->comp[cn].quant_tbl_no];
JHUFF_TBL *dc_table=cinfo->dc_huff_table[cinfo->comp[cn].dc_tbl_no];
JHUFF_TBL *ac_table=cinfo->ac_huff_table[cinfo->comp[cn].ac_tbl_no];
//处理每个DCT表--'Block'
for(tn=0;tn<cinfo->comp[cn].num_dct_table;tn++)
{
DCTVAL tmp=0;
DCTVAL *val=dct_table[tn];
int i;
for(i=0;i<DCTSIZE2;i++)val[i]-=128;//Forward-DCT的数据偏移
for(i=0;i<64;i++)temp_dct1[i]=val[i];//Forward-DCT计算
dsp_fdct_8x8((short *)val,1);
jutl_zigzag_sort((short*)val);//Z变换
//量化表
for(i=0;i<DCTSIZE2;i++)val[i]=(DCTVAL)((float)val[i]/(float)quant_table->quantval[i]+0.5);
//不同编码的计算
tmp=val[0];
val[0]-=cinfo->comp[cn].preval;
cinfo->comp[cn].preval=tmp;
jhuff_encode_one_block(cinfo, val, dc_table, ac_table);//Huffman
}
}
}
//添加量化表
void jint_add_quant_table(jpeg_compress_info *cinfo,u16 which_tbl,const u16 *base_tbl,float quality)
{
int i;
DCTVAL *qtblptr;
cinfo->quant_table[which_tbl]=&JQUANT_TBL_2[which_tbl];
qtblptr=cinfo->quant_table[which_tbl]->quantval;
for(i=0;i<DCTSIZE2;i++)qtblptr[i]=(short)(base_tbl[i]*quality+0.5);
jutl_zigzag_sort(qtblptr);
}
void jint_add_quant_table( jpeg_compress_info *cinfo,
unsigned int which_tbl, const UINT16 *base_tbl,
float quality)
{
int i;
DCTVAL *qtblptr;
cinfo->quant_table[which_tbl] = &JQUANT_TBL_2[which_tbl];//(JQUANT_TBL *)malloc(sizeof(JQUANT_TBL));
qtblptr = cinfo->quant_table[which_tbl]->quantval;
for (i=0; i<DCTSIZE2; i++)
{
qtblptr[i] = (INT16)(base_tbl[i] * quality + 0.5);//根据压缩质量产生新的量化表
}
jutl_zigzag_sort(qtblptr);
}
void jint_process_mcu(jpeg_compress_info *cinfo)
{
/* process every color component */
int cn, tn;
for (cn=0; cn<cinfo->num_comp; cn++)
{
/* Variable used in component. */
DCTBLOCK *dct_table = cinfo->comp[cn].dct_table;
JQUANT_TBL *quant_table = cinfo->quant_table[cinfo->comp[cn].quant_tbl_no];
JHUFF_TBL *dc_table = cinfo->dc_huff_table[cinfo->comp[cn].dc_tbl_no];
JHUFF_TBL *ac_table = cinfo->ac_huff_table[cinfo->comp[cn].ac_tbl_no];
/* process every DCT table -- 'Block'
*/
for (tn=0; tn<cinfo->comp[cn].num_dct_table; tn++)
{
DCTVAL tmp=0;
DCTVAL *val = dct_table[tn];
int i;
#ifdef DEBUG
show_dcttable(val, "\n\t[basic val]");
#endif
/* data offset for Forward-DCT
*/
for (i=0; i<DCTSIZE2; i++)
{
val[i] -= 128;
}
#ifdef DEBUG
show_dcttable(val, "[val -= 128]");//先减去128在DCT
#endif
/* Forward-DCT calculate
*/
//jjj
/* fdct_8x8(val); */
for(i = 0;i<64;i++)
temp_dct1[i] = val[i];
dsp_fdct_8x8((short *)val, 1);//DCT变换
//show_dcttable(val, "[fdct_8x8]");
//#ifdef DEBUG
//show_dcttable(val, "[fdct_8x8]");
//#endif
/* Zig-Zag Sort*/
jutl_zigzag_sort((INT16 *)val);//z排序
//jutl_zigzag_sort((DCTBLOCK *)val);
#ifdef DEBUG
show_dcttable(val, "[zig-zag sort]");
#endif
/* Quant */
for (i=0; i<DCTSIZE2; i++)
{
val[i] = (DCTVAL)((float)val[i]/(float)quant_table->quantval[i]+0.5);//量化
}
#ifdef DEBUG
show_dcttable(quant_table->quantval, "[quant-table]");
show_dcttable(val, "[quant]");
#endif
/* Difference encode calculate */
tmp = val[0];
val[0] -= cinfo->comp[cn].preval;//对DC进行差分编码
cinfo->comp[cn].preval = tmp;
#ifdef DEBUG
show_dcttable(val, "[diff code]");
#endif
/* Huffman */
jhuff_encode_one_block(cinfo, val, dc_table, ac_table);//对剩下的63个AC分量进行霍夫曼编码
}
}
}
