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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 <math.h>
#include <stdint.h>
#include <string.h>
#include <unistd.h>
/* Because the syntax for a function returning a function pointer is disgusting. */
typedef void (*process_func)(struct stream *left, struct stream *right, size_t n);
static void
usage(void)
{
eprintf("usage: %s operation right-hand-stream\n", argv0);
}
#define LIST_OPERATORS\
X(add, *lh += rh)\
X(sub, *lh -= rh)\
X(mul, *lh *= rh)\
X(div, *lh /= rh)\
X(exp, *lh = pow(*lh, rh))\
X(log, *lh = log(*lh) / log(rh))\
X(min, *lh = *lh < rh ? *lh : rh)\
X(max, *lh = *lh > rh ? *lh : rh)
#define X(NAME, ALGO)\
static void\
process_lf_##NAME(struct stream *left, struct stream *right, size_t n)\
{\
size_t i;\
double *lh, rh;\
for (i = 0; i < n; i += 4 * sizeof(double)) {\
lh = ((double *)(left->buf + i)) + 0, rh = ((double *)(right->buf + i))[0];\
ALGO;\
lh = ((double *)(left->buf + i)) + 1, rh = ((double *)(right->buf + i))[1];\
ALGO;\
lh = ((double *)(left->buf + i)) + 2, rh = ((double *)(right->buf + i))[2];\
ALGO;\
lh = ((double *)(left->buf + i)) + 3, rh = ((double *)(right->buf + i))[3];\
ALGO;\
}\
}
LIST_OPERATORS
#undef X
static process_func
get_lf_process(const char *operation)
{
#define X(NAME, ALGO)\
if (!strcmp(operation, #NAME)) return process_lf_##NAME;
LIST_OPERATORS
#undef X
eprintf("algorithm not recognised: %s\n", operation);
return NULL;
}
int
main(int argc, char *argv[])
{
struct stream left;
struct stream right;
ssize_t r;
size_t i, n;
process_func process = NULL;
ARGBEGIN {
default:
usage();
} ARGEND;
if (argc != 2)
usage();
left.file = "<stdin>";
left.fd = STDIN_FILENO;
einit_stream(&left);
right.file = argv[1];
right.fd = open(right.file, O_RDONLY);
if (right.fd < 0)
eprintf("open %s:", right.file);
einit_stream(&right);
if (left.width != right.width || left.height != right.height)
eprintf("videos do not have the same geometry\n");
if (left.pixel_size != right.pixel_size)
eprintf("videos use incompatible pixel formats\n");
if (!strcmp(left.pixfmt, "xyza"))
process = get_lf_process(argv[0]);
else
eprintf("pixel format %s is not supported, try xyza\n", left.pixfmt);
for (;;) {
if (left.ptr < sizeof(left.buf) && !eread_stream(&left, SIZE_MAX)) {
close(left.fd);
left.fd = -1;
break;
}
if (right.ptr < sizeof(right.buf) && !eread_stream(&right, SIZE_MAX)) {
close(right.fd);
right.fd = -1;
break;
}
n = left.ptr < right.ptr ? left.ptr : right.ptr;
n -= n % left.pixel_size;
left.ptr -= n;
right.ptr -= n;
process(&left, &right, n);
for (i = 0; i < n; i += (size_t)r) {
r = write(STDOUT_FILENO, left.buf + i, n - i);
if (r < 0)
eprintf("write <stdout>:");
}
if ((n & 3) || left.ptr != right.ptr) {
memmove(left.buf, left.buf + n, left.ptr);
memmove(right.buf, right.buf + n, right.ptr);
}
}
if (right.fd >= 0)
close(right.fd);
for (i = 0; i < left.ptr; i += (size_t)r) {
r = write(STDOUT_FILENO, left.buf + i, left.ptr - i);
if (r < 0)
eprintf("write <stdout>:");
}
if (left.fd >= 0) {
for (;;) {
left.ptr = 0;
if (!eread_stream(&left, SIZE_MAX)) {
close(left.fd);
left.fd = -1;
break;
}
for (i = 0; i < left.ptr; i += (size_t)r) {
r = write(STDOUT_FILENO, left.buf + i, left.ptr - i);
if (r < 0)
eprintf("write <stdout>:");
}
}
}
return 0;
}
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