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/* See LICENSE file for copyright and license details. */
#include "stream.h"
#include "util.h"
#include <fcntl.h>
#include <limits.h>
#include <stdint.h>
#include <string.h>
#include <unistd.h>
USAGE("start-point (end-point | 'end') file")
int
main(int argc, char *argv[])
{
struct stream stream;
size_t frame_size, start = 0, end = 0, ptr, max;
ssize_t r;
char buf[BUFSIZ];
int to_end = 0;
ENOFLAGS(argc != 3);
if (!strcmp(argv[0], "end"))
eprintf("refusing to create video with zero frames\n");
else
start = etozu_arg("the start point", argv[1], 0, SIZE_MAX);
if (!strcmp(argv[1], "end"))
to_end = 1;
else
end = etozu_arg("the end point", argv[1], 0, SIZE_MAX);
stream.file = argv[2];
stream.fd = eopen(stream.file, O_RDONLY);
einit_stream(&stream);
if (to_end)
end = stream.frames;
else if (end > stream.frames)
eprintf("end point is after end of video\n");
stream.frames = end - start;
fprint_stream_head(stdout, &stream);
efflush(stdout, "<stdout>");
echeck_frame_size(stream.width, stream.height, stream.pixel_size, 0, stream.file);
frame_size = stream.width * stream.height * stream.pixel_size;
if (stream.frames > SSIZE_MAX / frame_size)
eprintf("%s: video is too large\n", stream.file);
if (start >= end)
eprintf("%s\n", start > end ?
"start point is after end point" :
"refusing to create video with zero frames");
end = end * frame_size + stream.headlen;
start = start * frame_size + stream.headlen;
posix_fadvise(stream.fd, start, end - start, POSIX_FADV_SEQUENTIAL);
for (ptr = start; ptr < end; ptr += (size_t)r) {
max = end - ptr;
max = max < sizeof(buf) ? max : sizeof(buf);
r = pread(stream.fd, buf, max, ptr);
if (r < 0)
eprintf("pread %s:", stream.file);
if (r == 0)
eprintf("%s: file is shorter than expected\n", stream.file);
ewriteall(STDOUT_FILENO, buf, (size_t)r, "<stdout>");
}
close(stream.fd);
return 0;
}
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