cosmopolitan/dsp/mpeg/slowrgb.c

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2020-06-15 14:18:57 +00:00
/*-*- mode:c;indent-tabs-mode:t;c-basic-offset:4;tab-width:4;coding:utf-8 -*-│
vi: set et ft=c ts=4 sw=4 fenc=utf-8 :vi
PL_MPEG - MPEG1 Video decoder, MP2 Audio decoder, MPEG-PS demuxer
Dominic Szablewski - https://phoboslab.org │
The MIT License(MIT)
Copyright(c) 2019 Dominic Szablewski
Permission is hereby granted, free of charge, to any person obtaining
a copy of this software and associated documentation files(the
"Software"), to deal in the Software without restriction, including
without limitation the rights to use, copy, modify, merge, publish,
distribute, sublicense, and / or sell copies of the Software, and to
permit persons to whom the Software is furnished to do so, subject to
the following conditions:
The above copyright notice and this permission notice shall be
included in all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
NONINFRINGEMENT.IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.
*/
#include "dsp/mpeg/mpeg.h"
#include "libc/macros.h"
asm(".ident\t\"\\n\\n\
PL_MPEG (MIT License)\\n\
Copyright(c) 2019 Dominic Szablewski\\n\
https://phoboslab.org\"");
asm(".include \"libc/disclaimer.inc\"");
/**
* @see YCbCr2RGB() in tool/viz/lib/ycbcr2rgb.c
*/
void plm_frame_to_rgb(plm_frame_t *frame, uint8_t *rgb) {
// Chroma values are the same for each block of 4 pixels, so we proccess
// 2 lines at a time, 2 neighboring pixels each.
int w = frame->y.width, w2 = w >> 1;
int y_index1 = 0, y_index2 = w, y_next_2_lines = w + (w - frame->width);
int c_index = 0, c_next_line = w2 - (frame->width >> 1);
int rgb_index1 = 0, rgb_index2 = frame->width * 3,
rgb_next_2_lines = frame->width * 3;
int cols = frame->width >> 1, rows = frame->height >> 1;
int ccb, ccr, r, g, b;
uint8_t *y = frame->y.data, *cb = frame->cb.data, *cr = frame->cr.data;
for (int row = 0; row < rows; row++) {
for (int col = 0; col < cols; col++) {
ccb = cb[c_index];
ccr = cr[c_index];
c_index++;
r = (ccr + ((ccr * 103) >> 8)) - 179;
g = ((ccb * 88) >> 8) - 44 + ((ccr * 183) >> 8) - 91;
b = (ccb + ((ccb * 198) >> 8)) - 227;
// Line 1
int y1 = y[y_index1++];
int y2 = y[y_index1++];
rgb[rgb_index1 + 0] = MAX(0, MIN(255, y1 + r));
rgb[rgb_index1 + 1] = MAX(0, MIN(255, y1 - g));
rgb[rgb_index1 + 2] = MAX(0, MIN(255, y1 + b));
rgb[rgb_index1 + 3] = MAX(0, MIN(255, y2 + r));
rgb[rgb_index1 + 4] = MAX(0, MIN(255, y2 - g));
rgb[rgb_index1 + 5] = MAX(0, MIN(255, y2 + b));
rgb_index1 += 6;
// Line 2
int y3 = y[y_index2++];
int y4 = y[y_index2++];
rgb[rgb_index2 + 0] = MAX(0, MIN(255, y3 + r));
rgb[rgb_index2 + 1] = MAX(0, MIN(255, y3 - g));
rgb[rgb_index2 + 2] = MAX(0, MIN(255, y3 + b));
rgb[rgb_index2 + 3] = MAX(0, MIN(255, y4 + r));
rgb[rgb_index2 + 4] = MAX(0, MIN(255, y4 - g));
rgb[rgb_index2 + 5] = MAX(0, MIN(255, y4 + b));
rgb_index2 += 6;
}
y_index1 += y_next_2_lines;
y_index2 += y_next_2_lines;
rgb_index1 += rgb_next_2_lines;
rgb_index2 += rgb_next_2_lines;
c_index += c_next_line;
}
}