grafX2/tools/gifanalyzer/gifanalyzer.c
2018-01-30 13:50:14 +01:00

109 lines
2.8 KiB
C

/* vim:expandtab:ts=2 sw=2:
*/
/* Grafx2 - The Ultimate 256-color bitmap paint program
* Gif Analyzer tool
Copyright 2010 Adrien Destugues
Grafx2 is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License
as published by the Free Software Foundation; version 2
of the License.
Grafx2 is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with Grafx2; if not, see <http://www.gnu.org/licenses/>
*/
#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
#include <math.h>
int main(int argc, char* argv[])
{
FILE* theFile;
uint8_t buffer[256];
uint16_t w,h;
uint16_t x,y;
if(argc < 2)
{
printf("%s file.gif\n",argv[0]);
exit(-1);
}
theFile = fopen(argv[1], "r");
if (theFile == NULL)
{
fprintf(stderr, "Failed to open file '%s'.\n", argv[1]);
exit(1);
}
fread(buffer, 1, 6, theFile);
buffer[6] = 0;
printf("Signature: %6s\n", buffer);
fread(&w,2,1,theFile);
fread(&h,2,1,theFile);
printf("Resolution: %dx%d\n",w,h);
fread(buffer,1,3,theFile);
int colors = 1 << (((buffer[0] & 0x70)>>4)+1); // 0x70 == 0b01110000
int color_table_size = 1 << ((buffer[0]&0x7)+1);
printf("Color palette: 0x%02x\n",buffer[0]&0xFF);
if (buffer[0] & 0x80) { // 0x80 == 0b10000000
printf("\tGlobal palette");
if(buffer[0] & 0x08) // 0x08 == 0b00001000
printf(" SORTED");
printf("\n");
}
printf("\tColor count: %d\n", colors);
printf("\tSize of color table : %d\t", color_table_size);
printf("Index of background color: %d\n",buffer[1]);
printf("pixel aspect ratio = %d\n",buffer[2]);
if(buffer[2] != 0) printf("\t aspect ratio = %d/64\n", 15 + buffer[2]);
printf("Color palette:\n");
for (int i = 0; i < color_table_size; i++)
{
fread(buffer,1,3,theFile);
/*printf("\t%d: %u %u %u\t",i,buffer[0], buffer[1], buffer[2]);*/
printf(" %3d: #%02x%02x%02x",i,buffer[0], buffer[1], buffer[2]);
if ((i+1)%8 ==0)puts("");
}
int i = 0;
do {
fread(buffer,1,1,theFile);
i++;
} while (buffer[0] != ',');
if (i > 1)
printf("Skipped %d meaningless bytes before image descriptor\n",i);
fread(&x,2,1,theFile);
fread(&y,2,1,theFile);
fread(&w,2,1,theFile);
fread(&h,2,1,theFile);
fread(buffer,1,1,theFile);
printf("Image descriptor\n");
printf("\tx=%d y=%d w=%d h=%d\n",x,y,w,h);
printf("\t%sLocal Color Table (%d colors) %sSorted, %s\n",
(buffer[0]&0x80)?"":"No ", 1 << ((buffer[0]&0x07)+1),
(buffer[0]&0x20)?"":"Not ",
(buffer[0]&0x40)?"Interlaced":"Progressive");
fclose(theFile);
}