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/* See LICENSE file for copyright and license details. */
#include <arpa/inet.h>
#include <errno.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <png.h>
static char *argv0;
void
pngerr(png_structp pngs, const char *msg)
{
fprintf(stderr, "%s: libpng: %s\n", argv0, msg);
exit(1);
}
int
main(int argc, char *argv[])
{
png_structp pngs;
png_infop pngi;
size_t rowlen;
uint32_t hdr[4], width, height, i;
uint16_t *row;
argv0 = argv[0], argc--, argv++;
if (argc) {
fprintf(stderr, "usage: %s\n", argv0);
return 1;
}
/* header */
if (fread(hdr, sizeof(*hdr), 4, stdin) != 4) {
goto readerr;
}
if (memcmp("farbfeld", hdr, sizeof("farbfeld") - 1)) {
fprintf(stderr, "%s: invalid magic value\n", argv0);
return 1;
}
width = ntohl(hdr[2]);
height = ntohl(hdr[3]);
/* load png */
pngs = png_create_write_struct(PNG_LIBPNG_VER_STRING, NULL, pngerr,
NULL);
pngi = png_create_info_struct(pngs);
if (!pngs || !pngi) {
fprintf(stderr, "%s: failed to initialize libpng\n", argv0);
return 1;
}
png_init_io(pngs, stdout);
png_set_IHDR(pngs, pngi, width, height, 16, PNG_COLOR_TYPE_RGB_ALPHA,
PNG_INTERLACE_NONE, PNG_COMPRESSION_TYPE_BASE,
PNG_FILTER_TYPE_BASE);
png_write_info(pngs, pngi);
/* write rows */
if (width > SIZE_MAX / ((sizeof("RGBA") - 1) * sizeof(uint16_t))) {
fprintf(stderr, "%s: row length integer overflow\n", argv0);
return 1;
}
rowlen = width * (sizeof("RGBA") - 1);
if (!(row = malloc(rowlen * sizeof(uint16_t)))) {
fprintf(stderr, "%s: malloc: out of memory\n", argv0);
return 1;
}
for (i = 0; i < height; ++i) {
if (fread(row, sizeof(uint16_t), rowlen, stdin) != rowlen) {
goto readerr;
}
png_write_row(pngs, (uint8_t *)row);
}
png_write_end(pngs, NULL);
png_destroy_write_struct(&pngs, NULL);
return 0;
readerr:
if (ferror(stdin)) {
fprintf(stderr, "%s: fread: %s\n", argv0, strerror(errno));
} else {
fprintf(stderr, "%s: unexpected end of file\n", argv0);
}
return 1;
}
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