obs-studio/plugins/win-dshow/tiny-nv12-scale.c

208 lines
5.1 KiB
C

#include <string.h>
#include "tiny-nv12-scale.h"
/* TODO: optimize this stuff later, or replace with something better. it's
* kind of garbage. although normally it shouldn't be called that often. plus
* it's nearest neighbor so not really a huge deal. at the very least it
* should be sse2 at some point. */
void nv12_scale_init(nv12_scale_t *s, enum target_format format, int dst_cx,
int dst_cy, int src_cx, int src_cy)
{
s->format = format;
s->src_cx = src_cx;
s->src_cy = src_cy;
s->dst_cx = dst_cx;
s->dst_cy = dst_cy;
}
static void nv12_scale_nearest(nv12_scale_t *s, uint8_t *dst_start,
const uint8_t *src)
{
register uint8_t *dst = dst_start;
const int src_cx = s->src_cx;
const int src_cy = s->src_cy;
const int dst_cx = s->dst_cx;
const int dst_cy = s->dst_cy;
/* lum */
for (int y = 0; y < dst_cy; y++) {
const int src_line = y * src_cy / dst_cy * s->src_cx;
for (int x = 0; x < dst_cx; x++) {
const int src_x = x * src_cx / dst_cx;
*(dst++) = src[src_line + src_x];
}
}
src += src_cx * src_cy;
/* uv */
const int dst_cx_d2 = dst_cx / 2;
const int dst_cy_d2 = dst_cy / 2;
for (int y = 0; y < dst_cy_d2; y++) {
const int src_line = y * src_cy / dst_cy * src_cx;
for (int x = 0; x < dst_cx_d2; x++) {
const int src_x = x * src_cx / dst_cx * 2;
const int pos = src_line + src_x;
*(dst++) = src[pos];
*(dst++) = src[pos + 1];
}
}
}
static void nv12_scale_nearest_to_i420(nv12_scale_t *s, uint8_t *dst_start,
const uint8_t *src)
{
register uint8_t *dst = dst_start;
const int src_cx = s->src_cx;
const int src_cy = s->src_cy;
const int dst_cx = s->dst_cx;
const int dst_cy = s->dst_cy;
const int size = src_cx * src_cy;
/* lum */
for (int y = 0; y < dst_cy; y++) {
const int src_line = y * src_cy / dst_cy * s->src_cx;
for (int x = 0; x < dst_cx; x++) {
const int src_x = x * src_cx / dst_cx;
*(dst++) = src[src_line + src_x];
}
}
src += size;
/* uv */
const int dst_cx_d2 = dst_cx / 2;
const int dst_cy_d2 = dst_cy / 2;
register uint8_t *dst2 = dst + dst_cx * dst_cy / 4;
for (int y = 0; y < dst_cy_d2; y++) {
const int src_line = y * src_cy / dst_cy * src_cx;
for (int x = 0; x < dst_cx_d2; x++) {
const int src_x = x * src_cx / dst_cx * 2;
const int pos = src_line + src_x;
*(dst++) = src[pos];
*(dst2++) = src[pos + 1];
}
}
}
static void nv12_convert_to_i420(nv12_scale_t *s, uint8_t *dst_start,
const uint8_t *src_start)
{
const int size = s->src_cx * s->src_cy;
const int size_d4 = size / 4;
memcpy(dst_start, src_start, size);
register uint8_t *dst1 = dst_start + size;
register uint8_t *dst2 = dst1 + size_d4;
register uint8_t *dst_end = dst2 + size_d4;
register const uint8_t *src = src_start + size;
while (dst2 < dst_end) {
*(dst1++) = *(src++);
*(dst2++) = *(src++);
}
}
static void nv12_scale_nearest_to_yuy2(nv12_scale_t *s, uint8_t *dst_start,
const uint8_t *src)
{
register uint8_t *dst = dst_start;
const int src_cx = s->src_cx;
const int src_cy = s->src_cy;
const int dst_cx = s->dst_cx;
const int dst_cy = s->dst_cy;
const int src_cx_d2 = src_cx / 2;
const int src_cy_d2 = src_cy / 2;
const int dst_cx_d2 = dst_cx / 2;
const int dst_cy_d2 = dst_cy / 2;
const int size = src_cx * src_cy;
const uint8_t *src_uv = src + size;
register int uv_flip = 0;
for (int y = 0; y < dst_cy; y++) {
const int src_line = y * src_cy / dst_cy * s->src_cx;
const int src_line_d2 =
y / 2 * src_cy_d2 / dst_cy_d2 * s->src_cx;
for (int x = 0; x < dst_cx; x++) {
const int src_x = x * src_cx / dst_cx;
const int src_x_d2 = x / 2 * src_cx_d2 / dst_cx_d2;
const int pos = src_line + src_x;
const int pos_uv = src_line_d2 + src_x_d2 * 2 + uv_flip;
*(dst++) = src[pos];
*(dst++) = src_uv[pos_uv];
uv_flip ^= 1;
}
}
}
static void nv12_convert_to_yuy2(nv12_scale_t *s, uint8_t *dst_start,
const uint8_t *src_start)
{
const int size = s->src_cx * s->src_cy;
const int size_dst_line = s->src_cx * 4;
register const uint8_t *src_y = src_start;
register const uint8_t *src_uv = src_y + size;
register uint8_t *dst = dst_start;
register uint8_t *dst_end = dst + size * 2;
while (dst < dst_end) {
register uint8_t *dst_line_end = dst + size_dst_line;
const uint8_t *src_uv_start = src_uv;
while (dst < dst_line_end) {
*(dst++) = *(src_y++);
*(dst++) = *(src_uv++);
*(dst++) = *(src_y++);
*(dst++) = *(src_uv++);
}
dst_line_end = dst + size_dst_line;
src_uv = src_uv_start;
while (dst < dst_line_end) {
*(dst++) = *(src_y++);
*(dst++) = *(src_uv++);
*(dst++) = *(src_y++);
*(dst++) = *(src_uv++);
}
}
}
void nv12_do_scale(nv12_scale_t *s, uint8_t *dst, const uint8_t *src)
{
if (s->src_cx == s->dst_cx && s->src_cy == s->dst_cy) {
if (s->format == TARGET_FORMAT_I420)
nv12_convert_to_i420(s, dst, src);
else if (s->format == TARGET_FORMAT_YUY2)
nv12_convert_to_yuy2(s, dst, src);
else
memcpy(dst, src, s->src_cx * s->src_cy * 3 / 2);
} else {
if (s->format == TARGET_FORMAT_I420)
nv12_scale_nearest_to_i420(s, dst, src);
else if (s->format == TARGET_FORMAT_YUY2)
nv12_scale_nearest_to_yuy2(s, dst, src);
else
nv12_scale_nearest(s, dst, src);
}
}