/*
* Decode one block
*/
void
decode_block (int comp_no, int *out_buf, int *HuffBuff)
{
int QuantBuff[DCTSIZE2];
unsigned int *p_quant_tbl;
DecodeHuffMCU (HuffBuff, comp_no);
IZigzagMatrix (HuffBuff, QuantBuff);
p_quant_tbl =
&p_jinfo_quant_tbl_quantval[(int)p_jinfo_comps_info_quant_tbl_no[comp_no]][DCTSIZE2];
IQuantize (QuantBuff, p_quant_tbl);
ChenIDct (QuantBuff, out_buf);
PostshiftIDctMatrix (out_buf, IDCT_SHIFT);
BoundIDctMatrix (out_buf, IDCT_BOUNT);
}
/*
* Decode one block
*/
__attribute__((always_inline))void
decode_block(int comp_no, int *out_buf,
int *HuffBuff)
{
int QuantBuff[DCTSIZE2];
unsigned int* p_quant_tbl;
DecodeHuffMCU(HuffBuff, comp_no);
IZigzagMatrix(HuffBuff,QuantBuff);
p_quant_tbl =
&p_jinfo_quant_tbl_quantval[(int)p_jinfo_comps_info_quant_tbl_no[comp_no]][DCTSIZE2];
IQuantize(QuantBuff,(int *)p_quant_tbl);
//ChenIDct(QuantBuff, out_buf);
int *x = QuantBuff;
int *y = out_buf;
register int i;
register int *aptr;
register int a0,a1,a2,a3;
register int b0,b1,b2,b3;
register int c0,c1,c2,c3;
/* Loop over columns */
for(i=0;i<8;i++)
{
aptr = x+i;
b0 = LS(*aptr,2);
aptr += 8;
a0 = LS(*aptr,2);
aptr += 8;
b2 = LS(*aptr,2);
aptr += 8;
a1 = LS(*aptr,2);
aptr += 8;
b1 = LS(*aptr,2);
aptr += 8;
a2 = LS(*aptr,2);
aptr += 8;
b3 = LS(*aptr,2);
aptr += 8;
a3 = LS(*aptr,2);
/* Split into even mode b0 = x0 b1 = x4 b2 = x2 b3 = x6.
And the odd terms a0 = x1 a1 = x3 a2 = x5 a3 = x7.
*/
c0 = MSCALE((c7d16*a0)-(c1d16*a3));
c1 = MSCALE((c3d16*a2)-(c5d16*a1));
c2 = MSCALE((c3d16*a1)+(c5d16*a2));
c3 = MSCALE((c1d16*a0)+(c7d16*a3));
/* First Butterfly on even terms.*/
a0 = MSCALE(c1d4*(b0+b1));
a1 = MSCALE(c1d4*(b0-b1));
a2 = MSCALE((c3d8*b2)-(c1d8*b3));
a3 = MSCALE((c1d8*b2)+(c3d8*b3));
b0 = a0+a3;
b1 = a1+a2;
b2 = a1-a2;
b3 = a0-a3;
/* Second Butterfly */
a0 = c0+c1;
a1 = c0-c1;
a2 = c3-c2;
a3 = c3+c2;
c0 = a0;
c1 = MSCALE(c1d4*(a2-a1));
c2 = MSCALE(c1d4*(a2+a1));
c3 = a3;
aptr = y+i;
*aptr = b0+c3;
aptr += 8;
*aptr = b1+c2;
aptr += 8;
*aptr = b2+c1;
aptr += 8;
*aptr = b3+c0;
aptr += 8;
*aptr = b3-c0;
aptr += 8;
*aptr = b2-c1;
aptr += 8;
*aptr = b1-c2;
aptr += 8;
*aptr = b0-c3;
}
/* Loop over rows */
for(i=0;i<8;i++)
{
aptr = y+LS(i,3);
b0 = *(aptr++);
a0 = *(aptr++);
b2 = *(aptr++);
a1 = *(aptr++);
b1 = *(aptr++);
a2 = *(aptr++);
b3 = *(aptr++);
a3 = *(aptr);
/*
Split into even mode b0 = x0 b1 = x4 b2 = x2 b3 = x6.
And the odd terms a0 = x1 a1 = x3 a2 = x5 a3 = x7.
*/
c0 = MSCALE((c7d16*a0)-(c1d16*a3));
c1 = MSCALE((c3d16*a2)-(c5d16*a1));
c2 = MSCALE((c3d16*a1)+(c5d16*a2));
c3 = MSCALE((c1d16*a0)+(c7d16*a3));
/* First Butterfly on even terms.*/
a0 = MSCALE(c1d4*(b0+b1));
a1 = MSCALE(c1d4*(b0-b1));
a2 = MSCALE((c3d8*b2)-(c1d8*b3));
a3 = MSCALE((c1d8*b2)+(c3d8*b3));
/* Calculate last set of b's */
b0 = a0+a3;
b1 = a1+a2;
b2 = a1-a2;
b3 = a0-a3;
/* Second Butterfly */
a0 = c0+c1;
a1 = c0-c1;
a2 = c3-c2;
a3 = c3+c2;
c0 = a0;
c1 = MSCALE(c1d4*(a2-a1));
c2 = MSCALE(c1d4*(a2+a1));
c3 = a3;
aptr = y+LS(i,3);
*(aptr++) = b0+c3;
*(aptr++) = b1+c2;
*(aptr++) = b2+c1;
*(aptr++) = b3+c0;
*(aptr++) = b3-c0;
*(aptr++) = b2-c1;
*(aptr++) = b1-c2;
*(aptr) = b0-c3;
}
/*
Retrieve correct accuracy. We have additional factor
of 16 that must be removed.
*/
for(i=0,aptr=y;i<64;i++,aptr++)
*aptr = (((*aptr<0) ? (*aptr-8) : (*aptr+8)) /16);
PostshiftIDctMatrix(out_buf,IDCT_SHIFT);
BoundIDctMatrix(out_buf,IDCT_BOUNT);
}