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/* See LICENSE file for copyright and license details. */
#include <arpa/inet.h>
#include <errno.h>
#include <inttypes.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <jpeglib.h>
#include "arg.h"
#include "util.h"
static void
jpeg_error(j_common_ptr js)
{
fprintf(stderr, "%s: libjpeg: ", argv0);
(*js->err->output_message)(js);
exit(1);
}
static void
jpeg_setup_writer(struct jpeg_compress_struct *s, struct jpeg_error_mgr *e,
uint32_t w, uint32_t h, int quality, int opt)
{
jpeg_create_compress(s);
e->error_exit = jpeg_error;
s->err = jpeg_std_error(e);
jpeg_stdio_dest(s, stdout);
s->image_width = w;
s->image_height = h;
s->input_components = 3; /* color components per pixel */
s->in_color_space = JCS_RGB; /* output color space */
jpeg_set_defaults(s);
if (opt) {
s->optimize_coding = 1;
}
jpeg_set_quality(s, quality, 1);
jpeg_start_compress(s, 1);
}
static void
usage(void)
{
fprintf(stderr, "usage: %s [-b colour] [-o] [-q quality]\n", argv0);
exit(1);
}
int
main(int argc, char *argv[])
{
struct jpeg_compress_struct jcomp;
struct jpeg_error_mgr jerr;
size_t rowlen;
uint64_t a;
uint32_t width, height, i, j, k, l;
uint16_t *row, mask[3] = { 0xffff, 0xffff, 0xffff };
uint8_t *rowout;
int optimize = 0, quality = 85;
/* arguments */
ARGBEGIN {
case 'b':
if (parse_mask(EARGF(usage()), mask)) {
usage();
}
break;
case 'o':
optimize = 1;
break;
case 'q':
quality = estrtonum(EARGF(usage()), 0, 100);
break;
default:
usage();
} ARGEND
if (argc) {
usage();
}
/* prepare */
ff_read_header(&width, &height);
jpeg_setup_writer(&jcomp, &jerr, width, height, quality, optimize);
row = ereallocarray(NULL, width, (sizeof("RGBA") - 1) * sizeof(uint16_t));
rowlen = width * (sizeof("RGBA") - 1);
rowout = ereallocarray(NULL, width, (sizeof("RGB") - 1) * sizeof(uint8_t));
/* write data */
for (i = 0; i < height; ++i) {
if (fread(row, sizeof(uint16_t), rowlen, stdin) != rowlen) {
if (ferror(stdin)) {
fprintf(stderr, "%s: fread: %s\n", argv0,
strerror(errno));
} else {
fprintf(stderr, "%s: unexpected end of file\n",
argv0);
}
return 1;
}
for (j = 0, k = 0; j < rowlen; j += 4, k += 3) {
a = ntohs(row[j + 3]);
for (l = 0; l < 3; l++) {
/* alpha blending and 8-bit-reduction */
rowout[k + l] = (a * ntohs(row[j + l]) +
(UINT16_MAX - a) * mask[l]) /
(UINT16_MAX *
(UINT16_MAX / UINT8_MAX));
}
}
jpeg_write_scanlines(&jcomp, &rowout, 1);
}
/* clean up */
jpeg_finish_compress(&jcomp);
jpeg_destroy_compress(&jcomp);
return fshut(stdout, "<stdout>");
}
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