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/* See LICENSE file for copyright and license details. */
#include "arg.h"
#include "stream.h"
#include "util.h"
#include <alloca.h>
#include <fcntl.h>
#include <inttypes.h>
#include <limits.h>
#include <string.h>
#include <unistd.h>
static void
usage(void)
{
eprintf("usage: %s (file end-point) ...\n", argv0);
}
int
main(int argc, char *argv[])
{
struct stream stream;
size_t *ends, i, parts, ptr, end, frame_size, max, ptw, n;
FILE *fp;
int fd;
ssize_t r;
ARGBEGIN {
default:
usage();
} ARGEND;
if (argc < 2 || argc % 2)
usage();
stream.file = "<stdin>";
stream.fd = STDIN_FILENO;
einit_stream(&stream);
if (stream.width > SIZE_MAX / stream.height)
eprintf("%s: video is too large\n", stream.file);
frame_size = stream.width * stream.height;
if (stream.frames > SSIZE_MAX / frame_size)
eprintf("%s: video is too large\n", stream.file);
parts = (size_t)argc / 2;
ends = alloca(parts * sizeof(*ends));
for (i = 0; i < parts; i++) {
if (!strcmp(argv[i * 2 + 1], "end"))
ends[i] = stream.frames;
else if (tozu(argv[i * 2 + 1], 0, SIZE_MAX, ends + i))
eprintf("the end point must be an integer in [0, %zu]\n", SIZE_MAX);
if (i && ends[i] <= ends[i - 1])
eprintf("the end points must be in strictly ascending order\n");
if (ends[i] > stream.frames)
eprintf("frame %zu is beyond the end of the video\n", ends[i]);
}
ptr = 0;
for (i = 0; i < parts; i++) {
fd = open(argv[i * 2], O_WRONLY);
if (fd < 0)
eprintf("open %s:", argv[i * 2]);
fp = fdopen(fd, "wb");
stream.frames = ends[i] - (i ? ends[i - 1] : 0);
fprint_stream_head(fp, &stream);
fflush(fp);
if (ferror(fp))
eprintf("%s:", argv[i * 2]);
for (end = ends[i] * frame_size; ptr < end; ptr += n) {
for (ptw = ptr; stream.ptr && ptw < end;) {
max = end - ptw;
max = max < stream.ptr ? max : stream.ptr;
r = write(fd, stream.buf, max);
if (r < 0)
eprintf("write %s:\n", argv[i * 2]);
memmove(stream.buf, stream.buf + r, stream.ptr - (size_t)r);
}
n = eread_stream(&stream, end - ptr);
if (n == 0)
eprintf("%s: file is shorter than expected\n", stream.file);
}
if (fclose(fp))
eprintf("%s:", argv[i * 2]);
close(fd);
}
return 0;
}
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