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/* See LICENSE file for copyright and license details. */
#include <arpa/inet.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <png.h>
#define HEADER_FORMAT "farbfeld########"
int
main(int argc, char *argv[])
{
png_structp png_struct_p;
png_infop png_info_p;
uint8_t hdr[16];
uint16_t tmp16, *png_row;
png_uint_32 width, height, i;
png_size_t png_row_len, j;
if (argc > 1) {
fprintf(stderr, "usage: %s\n", argv[0]);
return 1;
}
/* header */
if (fread(hdr, 1, strlen(HEADER_FORMAT), stdin) != strlen(HEADER_FORMAT)) {
fprintf(stderr, "failed to read from stdin or input too short\n");
return 1;
}
if (memcmp("farbfeld", hdr, strlen("farbfeld"))) {
fprintf(stderr, "invalid magic in header\n");
return 1;
}
width = ntohl(*((uint32_t *)(hdr + 8)));
height = ntohl(*((uint32_t *)(hdr + 12)));
/* load png */
png_struct_p = png_create_write_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
png_info_p = png_create_info_struct(png_struct_p);
if (!png_struct_p || !png_info_p || setjmp(png_jmpbuf(png_struct_p))) {
fprintf(stderr, "failed to initialize libpng\n");
return 1;
}
png_init_io(png_struct_p, stdout);
png_set_IHDR(png_struct_p, png_info_p, width, height, 16, PNG_COLOR_TYPE_RGB_ALPHA,
PNG_INTERLACE_NONE, PNG_COMPRESSION_TYPE_BASE, PNG_FILTER_TYPE_BASE);
png_write_info(png_struct_p, png_info_p);
/* write rows */
png_row_len = strlen("RGBA") * width * sizeof(uint16_t);
png_row = malloc(png_row_len);
if (!png_row) {
fprintf(stderr, "failed to allocate row-buffer\n");
return 1;
}
for (i = 0; i < height; ++i) {
for (j = 0; j < png_row_len / sizeof(uint16_t); ++j) {
if (fread(&tmp16, 1, sizeof(uint16_t), stdin) != sizeof(uint16_t)) {
fprintf(stderr, "unexpected EOF or row-skew\n");
return 1;
}
png_row[j] = tmp16;
}
png_write_row(png_struct_p, (uint8_t *)png_row);
}
png_write_end(png_struct_p, NULL);
/* clean up */
png_free_data(png_struct_p, png_info_p, PNG_FREE_ALL, -1);
png_destroy_write_struct(&png_struct_p, NULL);
free(png_row);
return 0;
}
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