mozjpeg/simd/jsimd_mips.c

858 строки
20 KiB
C

/*
* jsimd_mips.c
*
* Copyright 2009 Pierre Ossman <ossman@cendio.se> for Cendio AB
* Copyright 2009-2011 D. R. Commander
* Copyright (C) 2013, MIPS Technologies, Inc., California
*
* Based on the x86 SIMD extension for IJG JPEG library,
* Copyright (C) 1999-2006, MIYASAKA Masaru.
* For conditions of distribution and use, see copyright notice in jsimdext.inc
*
* This file contains the interface between the "normal" portions
* of the library and the SIMD implementations when running on
* MIPS architecture.
*
* Based on the stubs from 'jsimd_none.c'
*/
#define JPEG_INTERNALS
#include "../jinclude.h"
#include "../jpeglib.h"
#include "../jsimd.h"
#include "../jdct.h"
#include "../jsimddct.h"
#include "jsimd.h"
#include <stdio.h>
#include <string.h>
#include <ctype.h>
static unsigned int simd_support = ~0;
#if defined(__linux__)
LOCAL(int)
parse_proc_cpuinfo(const char* search_string)
{
const char* file_name = "/proc/cpuinfo";
char cpuinfo_line[256];
FILE* f = NULL;
simd_support = 0;
if ((f = fopen(file_name, "r")) != NULL) {
while (fgets(cpuinfo_line, sizeof(cpuinfo_line), f) != NULL) {
if (strstr(cpuinfo_line, search_string) != NULL) {
fclose(f);
simd_support |= JSIMD_MIPS_DSPR2;
return 1;
}
}
fclose(f);
}
/* Did not find string in the proc file, or not Linux ELF. */
return 0;
}
#endif
/*
* Check what SIMD accelerations are supported.
*
* FIXME: This code is racy under a multi-threaded environment.
*/
LOCAL(void)
init_simd (void)
{
if (simd_support != ~0U)
return;
simd_support = 0;
#if defined(__mips__) && defined(__mips_dsp) && (__mips_dsp_rev >= 2)
simd_support |= JSIMD_MIPS_DSPR2;
#elif defined(__linux__)
/* We still have a chance to use MIPS DSPR2 regardless of globally used
* -mdspr2 options passed to gcc by performing runtime detection via
* /proc/cpuinfo parsing on linux */
if (!parse_proc_cpuinfo("MIPS 74K"))
return;
#endif
}
static const int mips_idct_ifast_coefs[4] = {
0x45404540, // FIX( 1.082392200 / 2) = 17734 = 0x4546
0x5A805A80, // FIX( 1.414213562 / 2) = 23170 = 0x5A82
0x76407640, // FIX( 1.847759065 / 2) = 30274 = 0x7642
0xAC60AC60 // FIX(-2.613125930 / 4) = -21407 = 0xAC61
};
GLOBAL(int)
jsimd_can_rgb_ycc (void)
{
init_simd();
/* The code is optimised for these values only */
if (BITS_IN_JSAMPLE != 8)
return 0;
if (sizeof(JDIMENSION) != 4)
return 0;
if ((RGB_PIXELSIZE != 3) && (RGB_PIXELSIZE != 4))
return 0;
if (simd_support & JSIMD_MIPS_DSPR2)
return 1;
return 0;
}
GLOBAL(int)
jsimd_can_rgb_gray (void)
{
init_simd();
/* The code is optimised for these values only */
if (BITS_IN_JSAMPLE != 8)
return 0;
if (sizeof(JDIMENSION) != 4)
return 0;
if ((RGB_PIXELSIZE != 3) && (RGB_PIXELSIZE != 4))
return 0;
if (simd_support & JSIMD_MIPS_DSPR2)
return 1;
return 0;
}
GLOBAL(int)
jsimd_can_ycc_rgb (void)
{
init_simd();
/* The code is optimised for these values only */
if (BITS_IN_JSAMPLE != 8)
return 0;
if (sizeof(JDIMENSION) != 4)
return 0;
if ((RGB_PIXELSIZE != 3) && (RGB_PIXELSIZE != 4))
return 0;
if (simd_support & JSIMD_MIPS_DSPR2)
return 1;
return 0;
}
GLOBAL(void)
jsimd_rgb_ycc_convert (j_compress_ptr cinfo,
JSAMPARRAY input_buf, JSAMPIMAGE output_buf,
JDIMENSION output_row, int num_rows)
{
void (*mipsdspr2fct)(JDIMENSION, JSAMPARRAY, JSAMPIMAGE, JDIMENSION, int);
switch(cinfo->in_color_space)
{
case JCS_EXT_RGB:
mipsdspr2fct=jsimd_extrgb_ycc_convert_mips_dspr2;
break;
case JCS_EXT_RGBX:
case JCS_EXT_RGBA:
mipsdspr2fct=jsimd_extrgbx_ycc_convert_mips_dspr2;
break;
case JCS_EXT_BGR:
mipsdspr2fct=jsimd_extbgr_ycc_convert_mips_dspr2;
break;
case JCS_EXT_BGRX:
case JCS_EXT_BGRA:
mipsdspr2fct=jsimd_extbgrx_ycc_convert_mips_dspr2;
break;
case JCS_EXT_XBGR:
case JCS_EXT_ABGR:
mipsdspr2fct=jsimd_extxbgr_ycc_convert_mips_dspr2;
break;
case JCS_EXT_XRGB:
case JCS_EXT_ARGB:
mipsdspr2fct=jsimd_extxrgb_ycc_convert_mips_dspr2;
break;
default:
mipsdspr2fct=jsimd_extrgb_ycc_convert_mips_dspr2;
break;
}
if (simd_support & JSIMD_MIPS_DSPR2)
mipsdspr2fct(cinfo->image_width, input_buf,
output_buf, output_row, num_rows);
}
GLOBAL(void)
jsimd_rgb_gray_convert (j_compress_ptr cinfo,
JSAMPARRAY input_buf, JSAMPIMAGE output_buf,
JDIMENSION output_row, int num_rows)
{
void (*mipsdspr2fct)(JDIMENSION, JSAMPARRAY, JSAMPIMAGE, JDIMENSION, int);
switch(cinfo->in_color_space)
{
case JCS_EXT_RGB:
mipsdspr2fct=jsimd_extrgb_gray_convert_mips_dspr2;
break;
case JCS_EXT_RGBX:
case JCS_EXT_RGBA:
mipsdspr2fct=jsimd_extrgbx_gray_convert_mips_dspr2;
break;
case JCS_EXT_BGR:
mipsdspr2fct=jsimd_extbgr_gray_convert_mips_dspr2;
break;
case JCS_EXT_BGRX:
case JCS_EXT_BGRA:
mipsdspr2fct=jsimd_extbgrx_gray_convert_mips_dspr2;
break;
case JCS_EXT_XBGR:
case JCS_EXT_ABGR:
mipsdspr2fct=jsimd_extxbgr_gray_convert_mips_dspr2;
break;
case JCS_EXT_XRGB:
case JCS_EXT_ARGB:
mipsdspr2fct=jsimd_extxrgb_gray_convert_mips_dspr2;
break;
default:
mipsdspr2fct=jsimd_extrgb_gray_convert_mips_dspr2;
break;
}
if (simd_support & JSIMD_MIPS_DSPR2)
mipsdspr2fct(cinfo->image_width, input_buf,
output_buf, output_row, num_rows);
}
GLOBAL(void)
jsimd_ycc_rgb_convert (j_decompress_ptr cinfo,
JSAMPIMAGE input_buf, JDIMENSION input_row,
JSAMPARRAY output_buf, int num_rows)
{
void (*mipsdspr2fct)(JDIMENSION, JSAMPIMAGE, JDIMENSION, JSAMPARRAY, int);
switch(cinfo->out_color_space)
{
case JCS_EXT_RGB:
mipsdspr2fct=jsimd_ycc_extrgb_convert_mips_dspr2;
break;
case JCS_EXT_RGBX:
case JCS_EXT_RGBA:
mipsdspr2fct=jsimd_ycc_extrgbx_convert_mips_dspr2;
break;
case JCS_EXT_BGR:
mipsdspr2fct=jsimd_ycc_extbgr_convert_mips_dspr2;
break;
case JCS_EXT_BGRX:
case JCS_EXT_BGRA:
mipsdspr2fct=jsimd_ycc_extbgrx_convert_mips_dspr2;
break;
case JCS_EXT_XBGR:
case JCS_EXT_ABGR:
mipsdspr2fct=jsimd_ycc_extxbgr_convert_mips_dspr2;
break;
case JCS_EXT_XRGB:
case JCS_EXT_ARGB:
mipsdspr2fct=jsimd_ycc_extxrgb_convert_mips_dspr2;
break;
default:
mipsdspr2fct=jsimd_ycc_extrgb_convert_mips_dspr2;
break;
}
if (simd_support & JSIMD_MIPS_DSPR2)
mipsdspr2fct(cinfo->output_width, input_buf,
input_row, output_buf, num_rows);
}
GLOBAL(int)
jsimd_can_h2v2_downsample (void)
{
init_simd();
/* The code is optimised for these values only */
if (BITS_IN_JSAMPLE != 8)
return 0;
if (sizeof(JDIMENSION) != 4)
return 0;
if (simd_support & JSIMD_MIPS_DSPR2)
return 1;
return 0;
}
GLOBAL(int)
jsimd_can_h2v1_downsample (void)
{
init_simd();
/* The code is optimised for these values only */
if (BITS_IN_JSAMPLE != 8)
return 0;
if (sizeof(JDIMENSION) != 4)
return 0;
if (simd_support & JSIMD_MIPS_DSPR2)
return 1;
return 0;
}
GLOBAL(void)
jsimd_h2v2_downsample (j_compress_ptr cinfo, jpeg_component_info * compptr,
JSAMPARRAY input_data, JSAMPARRAY output_data)
{
if (simd_support & JSIMD_MIPS_DSPR2)
jsimd_h2v2_downsample_mips_dspr2(cinfo->image_width,
cinfo->max_v_samp_factor, compptr->v_samp_factor,
compptr->width_in_blocks, input_data, output_data);
}
GLOBAL(void)
jsimd_h2v1_downsample (j_compress_ptr cinfo, jpeg_component_info * compptr,
JSAMPARRAY input_data, JSAMPARRAY output_data)
{
if (simd_support & JSIMD_MIPS_DSPR2)
jsimd_h2v1_downsample_mips_dspr2(cinfo->image_width,
cinfo->max_v_samp_factor, compptr->v_samp_factor,
compptr->width_in_blocks, input_data, output_data);
}
GLOBAL(int)
jsimd_can_h2v2_upsample (void)
{
init_simd();
/* The code is optimised for these values only */
if (BITS_IN_JSAMPLE != 8)
return 0;
if (sizeof(JDIMENSION) != 4)
return 0;
if (simd_support & JSIMD_MIPS_DSPR2)
return 1;
return 0;
}
GLOBAL(int)
jsimd_can_h2v1_upsample (void)
{
init_simd();
/* The code is optimised for these values only */
if (BITS_IN_JSAMPLE != 8)
return 0;
if (sizeof(JDIMENSION) != 4)
return 0;
if (simd_support & JSIMD_MIPS_DSPR2)
return 1;
return 0;
}
GLOBAL(void)
jsimd_h2v2_upsample (j_decompress_ptr cinfo,
jpeg_component_info * compptr,
JSAMPARRAY input_data,
JSAMPARRAY * output_data_ptr)
{
if (simd_support & JSIMD_MIPS_DSPR2)
jsimd_h2v2_upsample_mips_dspr2(cinfo->max_v_samp_factor,
cinfo->output_width, input_data, output_data_ptr);
}
GLOBAL(void)
jsimd_h2v1_upsample (j_decompress_ptr cinfo,
jpeg_component_info * compptr,
JSAMPARRAY input_data,
JSAMPARRAY * output_data_ptr)
{
if (simd_support & JSIMD_MIPS_DSPR2)
jsimd_h2v1_upsample_mips_dspr2(cinfo->max_v_samp_factor,
cinfo->output_width, input_data, output_data_ptr);
}
GLOBAL(int)
jsimd_can_h2v2_fancy_upsample (void)
{
init_simd();
/* The code is optimised for these values only */
if (BITS_IN_JSAMPLE != 8)
return 0;
if (sizeof(JDIMENSION) != 4)
return 0;
if (simd_support & JSIMD_MIPS_DSPR2)
return 1;
return 0;
}
GLOBAL(int)
jsimd_can_h2v1_fancy_upsample (void)
{
init_simd();
/* The code is optimised for these values only */
if (BITS_IN_JSAMPLE != 8)
return 0;
if (sizeof(JDIMENSION) != 4)
return 0;
if (simd_support & JSIMD_MIPS_DSPR2)
return 1;
return 0;
}
GLOBAL(void)
jsimd_h2v2_fancy_upsample (j_decompress_ptr cinfo,
jpeg_component_info * compptr,
JSAMPARRAY input_data,
JSAMPARRAY * output_data_ptr)
{
if (simd_support & JSIMD_MIPS_DSPR2)
jsimd_h2v2_fancy_upsample_mips_dspr2(cinfo->max_v_samp_factor,
compptr->downsampled_width, input_data, output_data_ptr);
}
GLOBAL(void)
jsimd_h2v1_fancy_upsample (j_decompress_ptr cinfo,
jpeg_component_info * compptr,
JSAMPARRAY input_data,
JSAMPARRAY * output_data_ptr)
{
if (simd_support & JSIMD_MIPS_DSPR2)
jsimd_h2v1_fancy_upsample_mips_dspr2(cinfo->max_v_samp_factor,
compptr->downsampled_width, input_data, output_data_ptr);
}
GLOBAL(int)
jsimd_can_h2v2_merged_upsample (void)
{
return 0;
}
GLOBAL(int)
jsimd_can_h2v1_merged_upsample (void)
{
return 0;
}
GLOBAL(void)
jsimd_h2v2_merged_upsample (j_decompress_ptr cinfo,
JSAMPIMAGE input_buf,
JDIMENSION in_row_group_ctr,
JSAMPARRAY output_buf)
{
}
GLOBAL(void)
jsimd_h2v1_merged_upsample (j_decompress_ptr cinfo,
JSAMPIMAGE input_buf,
JDIMENSION in_row_group_ctr,
JSAMPARRAY output_buf)
{
}
GLOBAL(int)
jsimd_can_convsamp (void)
{
init_simd();
/* The code is optimised for these values only */
if (DCTSIZE != 8)
return 0;
if (BITS_IN_JSAMPLE != 8)
return 0;
if (sizeof(JDIMENSION) != 4)
return 0;
if (sizeof(DCTELEM) != 2)
return 0;
if (simd_support & JSIMD_MIPS_DSPR2)
return 1;
return 0;
}
GLOBAL(int)
jsimd_can_convsamp_float (void)
{
init_simd();
/* The code is optimised for these values only */
if (DCTSIZE != 8)
return 0;
if (sizeof(JCOEF) != 2)
return 0;
if (BITS_IN_JSAMPLE != 8)
return 0;
if (sizeof(JDIMENSION) != 4)
return 0;
if (sizeof(ISLOW_MULT_TYPE) != 2)
return 0;
if ((simd_support & JSIMD_MIPS_DSPR2))
return 1;
return 0;
}
GLOBAL(void)
jsimd_convsamp (JSAMPARRAY sample_data, JDIMENSION start_col,
DCTELEM * workspace)
{
if (simd_support & JSIMD_MIPS_DSPR2)
jsimd_convsamp_mips_dspr2(sample_data, start_col, workspace);
}
GLOBAL(void)
jsimd_convsamp_float (JSAMPARRAY sample_data, JDIMENSION start_col,
FAST_FLOAT * workspace)
{
if ((simd_support & JSIMD_MIPS_DSPR2))
jsimd_convsamp_float_mips_dspr2(sample_data, start_col, workspace);
}
GLOBAL(int)
jsimd_can_fdct_islow (void)
{
init_simd();
/* The code is optimised for these values only */
if (DCTSIZE != 8)
return 0;
if (sizeof(DCTELEM) != 2)
return 0;
if (simd_support & JSIMD_MIPS_DSPR2)
return 1;
return 0;
}
GLOBAL(int)
jsimd_can_fdct_ifast (void)
{
init_simd();
/* The code is optimised for these values only */
if (DCTSIZE != 8)
return 0;
if (sizeof(DCTELEM) != 2)
return 0;
if (simd_support & JSIMD_MIPS_DSPR2)
return 1;
return 0;
}
GLOBAL(int)
jsimd_can_fdct_float (void)
{
return 0;
}
GLOBAL(void)
jsimd_fdct_islow (DCTELEM * data)
{
if (simd_support & JSIMD_MIPS_DSPR2)
jsimd_fdct_islow_mips_dspr2(data);
}
GLOBAL(void)
jsimd_fdct_ifast (DCTELEM * data)
{
if (simd_support & JSIMD_MIPS_DSPR2)
jsimd_fdct_ifast_mips_dspr2(data);
}
GLOBAL(void)
jsimd_fdct_float (FAST_FLOAT * data)
{
}
GLOBAL(int)
jsimd_can_quantize (void)
{
init_simd();
/* The code is optimised for these values only */
if (DCTSIZE != 8)
return 0;
if (sizeof(JCOEF) != 2)
return 0;
if (sizeof(DCTELEM) != 2)
return 0;
if (simd_support & JSIMD_MIPS_DSPR2)
return 1;
return 0;
}
GLOBAL(int)
jsimd_can_quantize_float (void)
{
init_simd();
/* The code is optimised for these values only */
if (DCTSIZE != 8)
return 0;
if (sizeof(JCOEF) != 2)
return 0;
if (BITS_IN_JSAMPLE != 8)
return 0;
if (sizeof(JDIMENSION) != 4)
return 0;
if (sizeof(ISLOW_MULT_TYPE) != 2)
return 0;
if ((simd_support & JSIMD_MIPS_DSPR2))
return 1;
return 0;
}
GLOBAL(void)
jsimd_quantize (JCOEFPTR coef_block, DCTELEM * divisors,
DCTELEM * workspace)
{
if (simd_support & JSIMD_MIPS_DSPR2)
jsimd_quantize_mips_dspr2(coef_block, divisors, workspace);
}
GLOBAL(void)
jsimd_quantize_float (JCOEFPTR coef_block, FAST_FLOAT * divisors,
FAST_FLOAT * workspace)
{
if ((simd_support & JSIMD_MIPS_DSPR2))
jsimd_quantize_float_mips_dspr2(coef_block, divisors, workspace);
}
GLOBAL(int)
jsimd_can_idct_2x2 (void)
{
init_simd();
/* The code is optimised for these values only */
if (DCTSIZE != 8)
return 0;
if (sizeof(JCOEF) != 2)
return 0;
if (BITS_IN_JSAMPLE != 8)
return 0;
if (sizeof(JDIMENSION) != 4)
return 0;
if (sizeof(ISLOW_MULT_TYPE) != 2)
return 0;
if ((simd_support & JSIMD_MIPS_DSPR2))
return 1;
return 0;
}
GLOBAL(int)
jsimd_can_idct_4x4 (void)
{
init_simd();
/* The code is optimised for these values only */
if (DCTSIZE != 8)
return 0;
if (sizeof(JCOEF) != 2)
return 0;
if (BITS_IN_JSAMPLE != 8)
return 0;
if (sizeof(JDIMENSION) != 4)
return 0;
if (sizeof(ISLOW_MULT_TYPE) != 2)
return 0;
if ((simd_support & JSIMD_MIPS_DSPR2))
return 1;
return 0;
}
GLOBAL(int)
jsimd_can_idct_6x6 (void)
{
init_simd();
/* The code is optimised for these values only */
if (DCTSIZE != 8)
return 0;
if (sizeof(JCOEF) != 2)
return 0;
if (BITS_IN_JSAMPLE != 8)
return 0;
if (sizeof(JDIMENSION) != 4)
return 0;
if (sizeof(ISLOW_MULT_TYPE) != 2)
return 0;
if ((simd_support & JSIMD_MIPS_DSPR2))
return 1;
return 0;
}
GLOBAL(int)
jsimd_can_idct_12x12 (void)
{
init_simd();
if (BITS_IN_JSAMPLE != 8)
return 0;
if (DCTSIZE != 8)
return 0;
if (sizeof(JCOEF) != 2)
return 0;
if (sizeof(JDIMENSION) != 4)
return 0;
if (sizeof(ISLOW_MULT_TYPE) != 2)
return 0;
if (simd_support & JSIMD_MIPS_DSPR2)
return 1;
return 0;
}
GLOBAL(void)
jsimd_idct_2x2 (j_decompress_ptr cinfo, jpeg_component_info * compptr,
JCOEFPTR coef_block, JSAMPARRAY output_buf,
JDIMENSION output_col)
{
if ((simd_support & JSIMD_MIPS_DSPR2))
jsimd_idct_2x2_mips_dspr2(compptr->dct_table, coef_block,
output_buf, output_col);
}
GLOBAL(void)
jsimd_idct_4x4 (j_decompress_ptr cinfo, jpeg_component_info * compptr,
JCOEFPTR coef_block, JSAMPARRAY output_buf,
JDIMENSION output_col)
{
if ((simd_support & JSIMD_MIPS_DSPR2))
{
int workspace[DCTSIZE*4]; /* buffers data between passes */
jsimd_idct_4x4_mips_dspr2(compptr->dct_table, coef_block,
output_buf, output_col, workspace);
}
}
GLOBAL(void)
jsimd_idct_6x6 (j_decompress_ptr cinfo, jpeg_component_info * compptr,
JCOEFPTR coef_block, JSAMPARRAY output_buf,
JDIMENSION output_col)
{
if ((simd_support & JSIMD_MIPS_DSPR2))
jsimd_idct_6x6_mips_dspr2(compptr->dct_table, coef_block,
output_buf, output_col);
}
GLOBAL(void)
jsimd_idct_12x12 (j_decompress_ptr cinfo, jpeg_component_info * compptr,
JCOEFPTR coef_block,
JSAMPARRAY output_buf, JDIMENSION output_col)
{
if (simd_support & JSIMD_MIPS_DSPR2) {
int workspace[96];
int output[12] = {
(int)(output_buf[0] + output_col),
(int)(output_buf[1] + output_col),
(int)(output_buf[2] + output_col),
(int)(output_buf[3] + output_col),
(int)(output_buf[4] + output_col),
(int)(output_buf[5] + output_col),
(int)(output_buf[6] + output_col),
(int)(output_buf[7] + output_col),
(int)(output_buf[8] + output_col),
(int)(output_buf[9] + output_col),
(int)(output_buf[10] + output_col),
(int)(output_buf[11] + output_col),
};
jsimd_idct_12x12_pass1_mips_dspr2(coef_block,
compptr->dct_table, workspace);
jsimd_idct_12x12_pass2_mips_dspr2(workspace, output);
}
}
GLOBAL(int)
jsimd_can_idct_islow (void)
{
return 0;
}
GLOBAL(int)
jsimd_can_idct_ifast (void)
{
init_simd();
/* The code is optimised for these values only */
if (DCTSIZE != 8)
return 0;
if (sizeof(JCOEF) != 2)
return 0;
if (BITS_IN_JSAMPLE != 8)
return 0;
if (sizeof(JDIMENSION) != 4)
return 0;
if (sizeof(IFAST_MULT_TYPE) != 2)
return 0;
if (IFAST_SCALE_BITS != 2)
return 0;
if ((simd_support & JSIMD_MIPS_DSPR2))
return 1;
return 0;
}
GLOBAL(int)
jsimd_can_idct_float (void)
{
return 0;
}
GLOBAL(void)
jsimd_idct_islow (j_decompress_ptr cinfo, jpeg_component_info * compptr,
JCOEFPTR coef_block, JSAMPARRAY output_buf,
JDIMENSION output_col)
{
}
GLOBAL(void)
jsimd_idct_ifast (j_decompress_ptr cinfo, jpeg_component_info * compptr,
JCOEFPTR coef_block, JSAMPARRAY output_buf,
JDIMENSION output_col)
{
if (simd_support & JSIMD_MIPS_DSPR2) {
JCOEFPTR inptr;
IFAST_MULT_TYPE * quantptr;
DCTELEM workspace[DCTSIZE2]; /* buffers data between passes */
/* Pass 1: process columns from input, store into work array. */
inptr = coef_block;
quantptr = (IFAST_MULT_TYPE *) compptr->dct_table;
jsimd_idct_ifast_cols_mips_dspr2(inptr, quantptr,
workspace, mips_idct_ifast_coefs);
/* Pass 2: process rows from work array, store into output array. */
/* Note that we must descale the results by a factor of 8 == 2**3, */
/* and also undo the PASS1_BITS scaling. */
jsimd_idct_ifast_rows_mips_dspr2(workspace, output_buf,
output_col, mips_idct_ifast_coefs);
}
}
GLOBAL(void)
jsimd_idct_float (j_decompress_ptr cinfo, jpeg_component_info * compptr,
JCOEFPTR coef_block, JSAMPARRAY output_buf,
JDIMENSION output_col)
{
}