Picture *Picture::yuv8_to_uyvy8(void) {
int i, j;
uint16_t u, v;
uint8_t y1, y2;
Picture *out = Picture::alloc(this->w, this->h, 2*this->w, UYVY8);
uint8_t *in_ptr, *out_ptr;
for (i = 0; i < this->h; i++) {
in_ptr = this->scanline(i);
out_ptr = out->scanline(i);
for (j = 0; j < this->w; j += 2) {
y1 = *in_ptr++;
u = *in_ptr++;
v = *in_ptr++;
y2 = *in_ptr++;
u += *in_ptr++;
v += *in_ptr++;
u /= 2;
v /= 2;
*out_ptr++ = u;
*out_ptr++ = y1;
*out_ptr++ = v;
*out_ptr++ = y2;
}
}
return out;
}
Picture *Picture::from_png(const char *filename) {
cairo_surface_t *pngs = cairo_image_surface_create_from_png(filename);
if (cairo_surface_status(pngs) != CAIRO_STATUS_SUCCESS) {
cairo_surface_destroy(pngs);
throw std::runtime_error("Failed to load PNG to Cairo surface");
}
cairo_format_t nf = cairo_image_surface_get_format(pngs);
if (nf != CAIRO_FORMAT_ARGB32 && nf != CAIRO_FORMAT_RGB24) {
cairo_surface_destroy(pngs);
throw std::runtime_error("PNG uses unsupported pixel format");
}
Picture *ret = Picture::alloc(
cairo_image_surface_get_width(pngs),
cairo_image_surface_get_height(pngs),
4*cairo_image_surface_get_width(pngs),
BGRA8
);
int xcopy = 4*ret->w;
int stride = cairo_image_surface_get_stride(pngs);
uint8_t *data = (uint8_t *)cairo_image_surface_get_data(pngs);
/* copy data */
for (int ycopy = 0; ycopy < ret->h; ++ycopy) {
memcpy(ret->scanline(ycopy), data + stride * ycopy, xcopy);
}
cairo_surface_destroy(pngs);
return ret;
}
Picture *Picture::uyvy8_to_yuv8(void) {
int i, j;
uint8_t u, y1, v, y2;
Picture *out = Picture::alloc(this->w, this->h, 3*this->w, YUV8);
uint8_t *in_ptr, *out_ptr;
for (i = 0; i < this->h; i++) {
in_ptr = this->scanline(i);
out_ptr = out->scanline(i);
for (j = 0; j < this->w; j+=2) {
u = *in_ptr++;
y1 = *in_ptr++;
v = *in_ptr++;
y2 = *in_ptr++;
*out_ptr++ = y1;
*out_ptr++ = u;
*out_ptr++ = v;
*out_ptr++ = y2;
*out_ptr++ = u;
*out_ptr++ = v;
}
}
return out;
}
Picture *Picture::bgra8_to_yuva8(void) {
int i, j;
uint8_t r, g, b, a;
uint16_t y, u, v;
Picture *out = Picture::alloc(this->w, this->h, 4*this->w, YUVA8);
uint8_t *pix_ptr, *out_ptr;
for (i = 0; i < this->h; i++) {
pix_ptr = this->scanline(i);
out_ptr = out->scanline(i);
for (j = 0; j < this->w; j++) {
b = *pix_ptr++;
g = *pix_ptr++;
r = *pix_ptr++;
a = *pix_ptr++;
y = 16 + (r * 66 + g * 129 + b * 25) / 256;
u = 128 + (b * 112 - g * 74 - r * 37) / 256;
v = 128 + (r * 112 - g * 94 - b * 18) / 256;
*out_ptr++ = y;
*out_ptr++ = u;
*out_ptr++ = v;
*out_ptr++ = a;
}
}
return out;
}
Picture *Picture::bgra8_to_rgb8(void) {
int i, j;
uint8_t r, g, b, a;
Picture *out = Picture::alloc(this->w, this->h, 3*this->w, RGB8);
uint8_t *pix_ptr, *out_ptr;
for (i = 0; i < this->h; i++) {
pix_ptr = this->scanline(i);
out_ptr = out->scanline(i);
for (j = 0; j < this->w; j++) {
b = *pix_ptr++;
g = *pix_ptr++;
r = *pix_ptr++;
a = *pix_ptr++;
*out_ptr++ = r;
*out_ptr++ = g;
*out_ptr++ = b;
}
}
return out;
}
Picture *Picture::rgb8_to_uyvy8(void) {
int i, j;
uint8_t r, g, b;
uint16_t y1, y2, u, v;
/* UYVY8 = 4 bytes/2 pixels (w must be even) */
assert(this->w % 2 == 0);
Picture *out = Picture::alloc(this->w, this->h, 2*this->w, UYVY8);
uint8_t *pix_ptr, *out_ptr;
for (i = 0; i < this->h; i++) {
pix_ptr = this->scanline(i);
out_ptr = out->scanline(i);
for (j = 0; j < this->w; j += 2) {
r = *pix_ptr++;
g = *pix_ptr++;
b = *pix_ptr++;
y1 = 16 + (r * 66 + g * 129 + b * 25) / 256;
u = 128 + (b * 112 - g * 74 - r * 37) / 256;
v = 128 + (r * 112 - g * 94 - b * 18) / 256;
r = *pix_ptr++;
g = *pix_ptr++;
b = *pix_ptr++;
y2 = 16 + (r * 66 + g * 129 + b * 25) / 256;
u += 128 + (b * 112 - g * 74 - r * 37) / 256;
v += 128 + (r * 112 - g * 94 - b * 18) / 256;
u >>= 1;
v >>= 1;
*out_ptr++ = u;
*out_ptr++ = y1;
*out_ptr++ = v;
*out_ptr++ = y2;
}
}
return out;
}
/* (maybe not anymore??) */
Picture *Picture::uyvy8_to_rgb8(void) {
int i, j;
int16_t r, g, b;
uint8_t u, y1, v, y2;
Picture *out = Picture::alloc(this->w, this->h, 3*this->w, RGB8);
uint8_t *in_ptr, *out_ptr;
for (i = 0; i < this->h; i++) {
in_ptr = this->scanline(i);
out_ptr = out->scanline(i);
for (j = 0; j < this->w; j += 2) {
u = *in_ptr++;
y1 = *in_ptr++;
v = *in_ptr++;
y2 = *in_ptr++;
r = (298 * y1 + 409 * v) / 256 - 223;
g = (298 * y1 - 100 * u - 208 * v) / 256 + 135;
b = (298 * y1 + 516 * u) / 256 - 277;
*out_ptr++ = SCLAMP(r);
*out_ptr++ = SCLAMP(g);
*out_ptr++ = SCLAMP(b);
r = (298 * y2 + 409 * v) / 256 - 223;
g = (298 * y2 - 100 * u - 208 * v) / 256 + 135;
b = (298 * y2 + 516 * u) / 256 - 277;
*out_ptr++ = SCLAMP(r);
*out_ptr++ = SCLAMP(g);
*out_ptr++ = SCLAMP(b);
}
}
return out;
}
