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/* See LICENSE file for copyright and license details. */
#ifndef TYPE
#include "common.h"
USAGE("key-stream")
#define FILE "blind-chroma-key.c"
#include "define-functions.h"
int
main(int argc, char *argv[])
{
struct stream stream, key;
void (*process)(struct stream *stream, struct stream *key);
UNOFLAGS(argc != 1);
eopen_stream(&stream, NULL);
eopen_stream(&key, argv[0]);
SELECT_PROCESS_FUNCTION(&stream);
CHECK_ALPHA_CHAN(&stream);
CHECK_N_CHAN(&stream, 4, 4);
if (strcmp(stream.pixfmt, key.pixfmt))
eprintf("videos use incompatible pixel formats\n");
if (key.width > 2 || key.height > 2 || key.width * key.height != 2)
eprintf("%s: each frame must contain exactly 2 pixels\n", key.file);
fprint_stream_head(stdout, &stream);
efflush(stdout, "<stdout>");
process(&stream, &key);
return 0;
}
#else
static void
PROCESS(struct stream *stream, struct stream *key)
{
size_t i, n, m = 0;
TYPE x1, y1, z1, a1, a2, variance2, *keyxyza;
TYPE x, y, z, d;
do {
if (!m) {
m = stream->frame_size;
while (key->ptr < key->frame_size)
if (!eread_stream(key, key->frame_size - key->ptr))
return;
keyxyza = (TYPE *)(key->buf);
x1 = keyxyza[0];
y1 = keyxyza[1];
z1 = keyxyza[2];
a1 = keyxyza[3];
x = x1 - keyxyza[4];
y = y1 - keyxyza[5];
z = z1 - keyxyza[6];
a2 = keyxyza[7];
variance2 = x * x + y * y + z * z;
/* TODO add more formulae: https://en.wikipedia.org/wiki/Color_difference */
if (a2 > a1) {
a1 = 1 - a1;
a2 = 1 - a2;
}
memmove(key->buf, key->buf + key->frame_size,
key->ptr -= key->frame_size);
}
n = MIN(stream->ptr, m) / stream->pixel_size;
for (i = 0; i < n; i++) {
x = ((TYPE *)(stream->buf))[4 * i + 0] - x1;
y = ((TYPE *)(stream->buf))[4 * i + 1] - y1;
z = ((TYPE *)(stream->buf))[4 * i + 2] - z1;
d = x * x + y * y + z * z;
if (d <= variance2) {
if (a1 == a2)
d = 0;
else
d = sqrt(d / variance2) * (a1 - a2) + a2;
((TYPE *)(stream->buf))[4 * i + 3] *= d;
}
}
n *= stream->pixel_size;
m -= n;
ewriteall(STDOUT_FILENO, stream->buf, n, "<stdout>");
memmove(stream->buf, stream->buf + n, stream->ptr -= n);
} while (eread_stream(stream, SIZE_MAX));
if (stream->ptr)
eprintf("%s: incomplete frame\n", stream->file);
}
#endif
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