diff options
Diffstat (limited to 'jpeg/jidctint.c')
| -rw-r--r-- | jpeg/jidctint.c | 50 |
1 files changed, 23 insertions, 27 deletions
diff --git a/jpeg/jidctint.c b/jpeg/jidctint.c index 8881a8f2..d7c3589e 100644 --- a/jpeg/jidctint.c +++ b/jpeg/jidctint.c @@ -1109,22 +1109,18 @@ jpeg_idct_1x1 (j_decompress_ptr cinfo, jpeg_component_info * compptr, JCOEFPTR coef_block, JSAMPARRAY output_buf, JDIMENSION output_col) { - DCTELEM dcval; + int dcval; ISLOW_MULT_TYPE * quantptr; JSAMPLE *range_limit = IDCT_range_limit(cinfo); - ISHIFT_TEMPS + SHIFT_TEMPS /* 1x1 is trivial: just take the DC coefficient divided by 8. */ - quantptr = (ISLOW_MULT_TYPE *) compptr->dct_table; - dcval = DEQUANTIZE(coef_block[0], quantptr[0]); CLAMP_DC(dcval); - /* Add range center and fudge factor for descale and range-limit. */ - dcval += (((DCTELEM) RANGE_CENTER) << 3) + (1 << 2); + dcval = (int) DESCALE((INT32) dcval, 3); - output_buf[0][output_col] = - range_limit[(int) IRIGHT_SHIFT(dcval, 3) & RANGE_MASK]; + output_buf[0][output_col] = range_limit[dcval & RANGE_MASK]; } @@ -4109,11 +4105,11 @@ jpeg_idct_2x1 (j_decompress_ptr cinfo, jpeg_component_info * compptr, JCOEFPTR coef_block, JSAMPARRAY output_buf, JDIMENSION output_col) { - DCTELEM tmp0, tmp1; + INT32 tmp0, tmp1; ISLOW_MULT_TYPE * quantptr; JSAMPROW outptr; JSAMPLE *range_limit = IDCT_range_limit(cinfo); - ISHIFT_TEMPS + SHIFT_TEMPS /* Pass 1: empty. */ @@ -4126,8 +4122,8 @@ jpeg_idct_2x1 (j_decompress_ptr cinfo, jpeg_component_info * compptr, tmp0 = DEQUANTIZE(coef_block[0], quantptr[0]); CLAMP_DC(tmp0); - /* Add range center and fudge factor for final descale and range-limit. */ - tmp0 += (((DCTELEM) RANGE_CENTER) << 3) + (1 << 2); + /* Add fudge factor here for final descale. */ + tmp0 += ONE << 2; /* Odd part */ @@ -4135,8 +4131,8 @@ jpeg_idct_2x1 (j_decompress_ptr cinfo, jpeg_component_info * compptr, /* Final output stage */ - outptr[0] = range_limit[(int) IRIGHT_SHIFT(tmp0 + tmp1, 3) & RANGE_MASK]; - outptr[1] = range_limit[(int) IRIGHT_SHIFT(tmp0 - tmp1, 3) & RANGE_MASK]; + outptr[0] = range_limit[(int) RIGHT_SHIFT(tmp0 + tmp1, 3) & RANGE_MASK]; + outptr[1] = range_limit[(int) RIGHT_SHIFT(tmp0 - tmp1, 3) & RANGE_MASK]; } @@ -4956,8 +4952,6 @@ jpeg_idct_4x8 (j_decompress_ptr cinfo, jpeg_component_info * compptr, */ z2 = DEQUANTIZE(inptr[DCTSIZE*0], quantptr[DCTSIZE*0]); - if (ctr == 4) - CLAMP_DC(z2); z3 = DEQUANTIZE(inptr[DCTSIZE*4], quantptr[DCTSIZE*4]); z2 <<= CONST_BITS; z3 <<= CONST_BITS; @@ -5286,32 +5280,34 @@ jpeg_idct_1x2 (j_decompress_ptr cinfo, jpeg_component_info * compptr, JCOEFPTR coef_block, JSAMPARRAY output_buf, JDIMENSION output_col) { - DCTELEM tmp0, tmp1; + INT32 tmp0, tmp1; ISLOW_MULT_TYPE * quantptr; + JSAMPROW outptr; JSAMPLE *range_limit = IDCT_range_limit(cinfo); - ISHIFT_TEMPS + SHIFT_TEMPS + + /* Pass 1: empty. */ - /* Process 1 column from input, store into output array. */ + /* Pass 2: process 1 row from input, store into output array. */ quantptr = (ISLOW_MULT_TYPE *) compptr->dct_table; + outptr = output_buf[0] + output_col; /* Even part */ - tmp0 = DEQUANTIZE(coef_block[DCTSIZE*0], quantptr[DCTSIZE*0]); + tmp0 = DEQUANTIZE(coef_block[0], quantptr[0]); CLAMP_DC(tmp0); - /* Add range center and fudge factor for final descale and range-limit. */ - tmp0 += (((DCTELEM) RANGE_CENTER) << 3) + (1 << 2); + /* Add fudge factor here for final descale. */ + tmp0 += ONE << 2; /* Odd part */ - tmp1 = DEQUANTIZE(coef_block[DCTSIZE*1], quantptr[DCTSIZE*1]); + tmp1 = DEQUANTIZE(coef_block[1], quantptr[1]); /* Final output stage */ - output_buf[0][output_col] = - range_limit[(int) IRIGHT_SHIFT(tmp0 + tmp1, 3) & RANGE_MASK]; - output_buf[1][output_col] = - range_limit[(int) IRIGHT_SHIFT(tmp0 - tmp1, 3) & RANGE_MASK]; + outptr[0] = range_limit[(int) RIGHT_SHIFT(tmp0 + tmp1, 3) & RANGE_MASK]; + outptr[1] = range_limit[(int) RIGHT_SHIFT(tmp0 - tmp1, 3) & RANGE_MASK]; } #endif /* IDCT_SCALING_SUPPORTED */ |