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/*
* Copyright 2008 Sean Fox <dyntryx@gmail.com>
* Copyright 2008 James Bursa <james@netsurf-browser.org>
*
* This file is part of NetSurf's libnsgif, http://www.netsurf-browser.org/
* Licenced under the MIT License,
* http://www.opensource.org/licenses/mit-license.php
*/
#include <assert.h>
#include <errno.h>
#include <stdbool.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <sys/stat.h>
#include "../include/nsgif.h"
#define BYTES_PER_PIXEL 4
static void *bitmap_create(int width, int height)
{
/* Ensure a stupidly large bitmap is not created */
if (width > 4096 || height > 4096) {
return NULL;
}
return calloc(width * height, BYTES_PER_PIXEL);
}
static unsigned char *bitmap_get_buffer(void *bitmap)
{
return bitmap;
}
static void bitmap_destroy(void *bitmap)
{
free(bitmap);
}
static uint8_t *load_file(const char *path, size_t *data_size)
{
FILE *fd;
struct stat sb;
unsigned char *buffer;
size_t size;
size_t n;
fd = fopen(path, "rb");
if (!fd) {
perror(path);
exit(EXIT_FAILURE);
}
if (stat(path, &sb)) {
perror(path);
exit(EXIT_FAILURE);
}
size = sb.st_size;
buffer = malloc(size);
if (!buffer) {
fprintf(stderr, "Unable to allocate %lld bytes\n",
(long long) size);
exit(EXIT_FAILURE);
}
n = fread(buffer, 1, size, fd);
if (n != size) {
perror(path);
exit(EXIT_FAILURE);
}
fclose(fd);
*data_size = size;
return buffer;
}
static void warning(const char *context, nsgif_result gif_res)
{
fprintf(stderr, "%s failed: ", context);
switch (gif_res) {
case NSGIF_FRAME_DATA_ERROR:
fprintf(stderr, "NSGIF_FRAME_DATA_ERROR");
break;
case NSGIF_INSUFFICIENT_DATA:
fprintf(stderr, "NSGIF_INSUFFICIENT_DATA");
break;
case NSGIF_DATA_ERROR:
fprintf(stderr, "NSGIF_DATA_ERROR");
break;
case NSGIF_INSUFFICIENT_MEMORY:
fprintf(stderr, "NSGIF_INSUFFICIENT_MEMORY");
break;
default:
fprintf(stderr, "unknown code %i", gif_res);
break;
}
fprintf(stderr, "\n");
}
static void write_ppm(FILE* fh, const char *name, nsgif *gif, bool no_write)
{
nsgif_result gif_res;
uint32_t frame_prev = 0;
const nsgif_info_t *info;
info = nsgif_get_info(gif);
if (!no_write) {
fprintf(fh, "P3\n");
fprintf(fh, "# %s\n", name);
fprintf(fh, "# width %u \n", info->width);
fprintf(fh, "# height %u \n", info->height);
fprintf(fh, "# frame_count %u \n", info->frame_count);
fprintf(fh, "# loop_max %u \n", info->loop_max);
fprintf(fh, "%u %u 256\n", info->width,
info->height * info->frame_count);
}
/* decode the frames */
while (true) {
const uint32_t *buffer;
const uint8_t *image;
uint32_t frame_new;
uint32_t delay_cs;
nsgif_rect area;
gif_res = nsgif_frame_prepare(gif, &area,
&delay_cs, &frame_new);
if (gif_res != NSGIF_OK) {
warning("nsgif_frame_prepare", gif_res);
return;
}
if (frame_new < frame_prev) {
/* Must be an animation that loops. We only care about
* decoding each frame once. */
return;
}
frame_prev = frame_new;
gif_res = nsgif_frame_decode(gif, frame_new, &buffer);
if (gif_res != NSGIF_OK) {
warning("nsgif_decode_frame", gif_res);
return;
}
if (!no_write) {
fprintf(fh, "# frame %u:\n", frame_new);
image = (const uint8_t *) buffer;
for (uint32_t y = 0; y != info->height; y++) {
for (uint32_t x = 0; x != info->width; x++) {
size_t z = (y * info->width + x) * 4;
fprintf(fh, "%u %u %u ",
image[z],
image[z + 1],
image[z + 2]);
}
fprintf(fh, "\n");
}
}
}
}
int main(int argc, char *argv[])
{
const nsgif_bitmap_cb_vt bitmap_callbacks = {
.create = bitmap_create,
.destroy = bitmap_destroy,
.get_buffer = bitmap_get_buffer,
};
nsgif *gif;
size_t size;
uint8_t *data;
FILE *outf = stdout;
nsgif_result gif_res;
bool no_write = false;
if (argc < 2) {
fprintf(stderr, "Usage: %s image.gif [out]\n", argv[0]);
fprintf(stderr, "\n");
fprintf(stderr, "If [out] is NOWRITE, the gif will be docoded "
"but not output.\n");
fprintf(stderr, "Otherwise [out] is an output filename.\n");
fprintf(stderr, "When [out] is unset, output is to stdout.\n");
return 1;
}
if (argc > 2) {
if (strcmp(argv[2], "NOWRITE") == 0) {
no_write = true;
} else {
outf = fopen(argv[2], "w+");
if (outf == NULL) {
fprintf(stderr, "Unable to open %s for writing\n", argv[2]);
return 2;
}
}
}
/* create our gif animation */
gif_res = nsgif_create(&bitmap_callbacks, &gif);
if (gif_res != NSGIF_OK) {
return 1;
}
/* load file into memory */
data = load_file(argv[1], &size);
/* begin decoding */
do {
gif_res = nsgif_data_scan(gif, size, data);
if (gif_res != NSGIF_OK && gif_res != NSGIF_WORKING) {
warning("nsgif_data_scan", gif_res);
nsgif_destroy(gif);
free(data);
return 1;
}
} while (gif_res != NSGIF_OK);
write_ppm(outf, argv[1], gif, no_write);
if (argc > 2 && !no_write) {
fclose(outf);
}
/* clean up */
nsgif_destroy(gif);
free(data);
return 0;
}
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