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/* See LICENSE file for copyright and license details. */
#include "arg.h"
#include "stream.h"
#include "util.h"
#include <fcntl.h>
#include <inttypes.h>
#include <string.h>
#include <unistd.h>
static void
usage(void)
{
eprintf("usage: width height left top %s\n", argv0);
}
int
main(int argc, char *argv[])
{
struct stream stream;
char *buf, *image;
size_t width = 0, height = 0, left = 0, top = 0;
size_t off, y, irown, orown, ptr, n, m;
ssize_t r;
ARGBEGIN {
default:
usage();
} ARGEND;
if (argc != 4)
usage();
if (tozu(argv[0], 1, SIZE_MAX, &width))
eprintf("width be an integer in [1, %zu]\n", SIZE_MAX);
if (tozu(argv[1], 1, SIZE_MAX, &height))
eprintf("height be an integer in [1, %zu]\n", SIZE_MAX);
if (tozu(argv[2], 0, SIZE_MAX, &left))
eprintf("left position be an integer in [0, %zu]\n", SIZE_MAX);
if (tozu(argv[3], 0, SIZE_MAX, &top))
eprintf("top position be an integer in [0, %zu]\n", SIZE_MAX);
stream.file = "<stdin>";
stream.fd = STDIN_FILENO;
einit_stream(&stream);
if (left + width > stream.width || top + height > stream.height)
eprintf("crop area extends beyond original image\n");
n = stream.width, stream.width = width;
m = stream.height, stream.height = height;
fprint_stream_head(stdout, &stream);
stream.width = n;
stream.height = m;
fflush(stdout);
if (ferror(stdout))
eprintf("<stdout>:");
if (stream.width > SIZE_MAX / stream.pixel_size)
eprintf("<stdin>: video frame is too large\n");
n = irown = stream.width * stream.pixel_size;
if (n > SIZE_MAX / stream.height)
eprintf("<stdin>: video frame is too large\n");
n *= stream.height;
if (!(buf = malloc(n)))
eprintf("malloc:");
m = height * (orown = width * stream.pixel_size);
if (!(image = malloc(m)))
eprintf("malloc:");
off = top * irown + left * stream.pixel_size;
memcpy(buf, stream.buf, ptr = stream.ptr);
for (;;) {
for (; ptr < n; ptr += (size_t)r) {
r = read(stream.fd, buf + ptr, n - ptr);
if (r < 0) {
eprintf("read %s:", stream.file);
} else if (r == 0) {
if (!ptr)
break;
eprintf("%s: incomplete frame", stream.file);
}
}
if (!ptr)
break;
for (y = 0; y < height; y++)
memcpy(image + y * orown, buf + y * irown + off, orown);
for (ptr = 0; ptr < m; ptr += (size_t)r) {
r = write(STDOUT_FILENO, image + ptr, m - ptr);
if (r < 0)
eprintf("write <stdout>");
}
}
return 0;
}
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