On Mon, 14 Jul 2014 14:54:42 -0400
Charlie Murphy <cmsmur...@gmail.com> wrote:
> I'm looking for something like this[1] but with conversion tools for
> other formats.
Now, let's take a look at the proposition:
Bytes Description
9 ASCII string: "imagefile"
1 Blank
9 Right-justified, blank-padded ASCII string containing width.
1 Blank
9 Right-justified, blank-padded ASCII string containing height.
1 Blank
The given example-implementation leaves a lot to ask for. Here's my
approach:
char *
readimage(int fd, int *w, int *h)
{
size_t total;
uint8_t *data;
data = malloc(30);
if (!data || read(fd, buf, 30) != 30 || strcmp(buf, "imagefile") != 0) {
free(data);
return NULL;
}
buf[9] = buf[19] = buf[29] = '\0';
*w = atoi(buf+10);
*h = atoi(buf+20);
total = (*w) * (*h) * 4;
data = realloc(data, total);
if (!data || read(fd, data, total) != total) {
free(data);
return NULL;
}
return data;
}
The writing-function is rather trivial.
Now, what puzzles me is why no explanation is given on how the data
itself should be stored. It says RGBA, so I suppose he meant
| 8 bit | 8 bit | 8 bit | 8 bit |
| red | green | blue | alpha |
for each pixel. This is rather trivial then, given an unsigned
8-bit-integer can be expressed with his according ASCII-char, basically
turning this image file-format into a string:
imagefile 2 1 5%4&4"31
Let me know what you think. I suppose anything more complex than that will
limit our possibilities and the flexiblity and simplicity of this format.
Cheers
FRIGN
--
FRIGN <d...@frign.de>
