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/* See LICENSE file for copyright and license details. */
#include "stream.h"
#include "util.h"
#include <limits.h>
#include <unistd.h>
USAGE("[-i] file")
static void
to_stdout(struct stream *stream, size_t frame_size)
{
size_t ptr, end, n;
char buf[BUFSIZ];
ssize_t r;
while (stream->frames--) {
ptr = stream->frames * frame_size + stream->headlen;
end = ptr + frame_size;
while (ptr < end) {
if (!(r = epread(stream->fd, buf, MIN(sizeof(buf), end - ptr), ptr, stream->file)))
eprintf("%s: file is shorter than expected\n", stream->file);
ptr += n = (size_t)r;
ewriteall(STDOUT_FILENO, buf, n, "<stdout>");
}
}
}
static void
elseek_set(int fd, off_t offset, const char *fname)
{
off_t r = elseek(fd, offset, SEEK_SET, fname);
if (r != offset)
eprintf("%s: file is shorter than expected\n", fname);
}
static void
epread_frame(struct stream *stream, char *buf, off_t off, size_t n)
{
stream->ptr = stream->xptr = 0;
elseek_set(stream->fd, off, stream->file);
eread_frame(stream, buf, n);
}
static void
epwrite_frame(struct stream *stream, char *buf, off_t off, size_t n)
{
elseek_set(stream->fd, off, stream->file);
ewriteall(stream->fd, buf, n, stream->file);
}
static void
in_place(struct stream *stream, size_t frame_size)
{
size_t f, fm = stream->frames - 1;
off_t pa, pb;
char *bufa, *bufb;
bufa = emalloc(frame_size);
bufb = emalloc(frame_size);
for (f = 0; f < stream->frames >> 1; f++) {
pa = f * frame_size + stream->headlen;
pb = (fm - f) * frame_size + stream->headlen;
epread_frame(stream, bufa, pa, frame_size);
epread_frame(stream, bufb, pb, frame_size);
epwrite_frame(stream, bufa, pb, frame_size);
epwrite_frame(stream, bufb, pa, frame_size);
}
free(bufa);
free(bufb);
}
int
main(int argc, char *argv[])
{
struct stream stream;
size_t frame_size;
int inplace = 0;
ARGBEGIN {
case 'i':
inplace = 1;
break;
default:
usage();
} ARGEND;
if (argc != 1)
usage();
stream.file = argv[0];
stream.fd = eopen(stream.file, inplace ? O_RDWR : O_RDONLY);
einit_stream(&stream);
if (!inplace) {
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 > (size_t)SSIZE_MAX / frame_size ||
stream.frames * frame_size > (size_t)SSIZE_MAX - stream.headlen)
eprintf("%s: video is too large\n", stream.file);
#if defined(POSIX_FADV_RANDOM)
posix_fadvise(stream.fd, 0, 0, POSIX_FADV_RANDOM);
#endif
(inplace ? in_place : to_stdout)(&stream, frame_size);
close(stream.fd);
return 0;
}
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