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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>
#define HEADER "farbfeld########"
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 png_row_len, j;
uint32_t width, height, i;
uint16_t tmp16, *png_row;
uint8_t hdr[16];
argv0 = argv[0], argc--, argv++;
if (argc) {
fprintf(stderr, "usage: %s\n", argv0);
return 1;
}
/* header */
if (fread(hdr, 1, strlen(HEADER), stdin) != strlen(HEADER)) {
fprintf(stderr, "%s: incomplete header\n", argv0);
return 1;
}
if (memcmp("farbfeld", hdr, strlen("farbfeld"))) {
fprintf(stderr, "%s: invalid magic value\n", argv0);
return 1;
}
width = ntohl(*((uint32_t *)(hdr + 8)));
height = ntohl(*((uint32_t *)(hdr + 12)));
/* 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 */
png_row_len = strlen("RGBA") * width * sizeof(uint16_t);
if (!(png_row = malloc(png_row_len))) {
fprintf(stderr, "%s: malloc: out of memory\n", argv0);
return 1;
}
for (i = 0; i < height; ++i) {
for (j = 0; j < png_row_len / sizeof(uint16_t); ++j) {
if (fread(&tmp16, sizeof(uint16_t), 1, stdin) != 1) {
fprintf(stderr, "%s: unexpected EOF\n", argv0);
return 1;
}
png_row[j] = tmp16;
}
png_write_row(pngs, (uint8_t *)png_row);
}
png_write_end(pngs, NULL);
png_destroy_write_struct(&pngs, NULL);
return 0;
}
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