mirror of https://github.com/opencv/opencv.git
Open Source Computer Vision Library
https://opencv.org/
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
53 lines
1.5 KiB
53 lines
1.5 KiB
12 years ago
|
// Copyright 2010 Google Inc. All Rights Reserved.
|
||
|
|
//
|
||
|
|
// This code is licensed under the same terms as WebM:
|
||
|
|
// Software License Agreement: http://www.webmproject.org/license/software/
|
||
|
|
// Additional IP Rights Grant: http://www.webmproject.org/license/additional/
|
||
|
|
// -----------------------------------------------------------------------------
|
||
|
|
//
|
||
|
|
// YUV->RGB conversion function
|
||
|
|
//
|
||
|
|
// Author: Skal (pascal.massimino@gmail.com)
|
||
|
|
|
||
|
|
#include "./yuv.h"
|
||
|
|
|
||
|
|
#if defined(__cplusplus) || defined(c_plusplus)
|
||
|
|
extern "C" {
|
||
|
|
#endif
|
||
|
|
|
||
|
|
enum { YUV_HALF = 1 << (YUV_FIX - 1) };
|
||
|
|
|
||
|
|
int16_t VP8kVToR[256], VP8kUToB[256];
|
||
|
|
int32_t VP8kVToG[256], VP8kUToG[256];
|
||
|
|
uint8_t VP8kClip[YUV_RANGE_MAX - YUV_RANGE_MIN];
|
||
|
|
uint8_t VP8kClip4Bits[YUV_RANGE_MAX - YUV_RANGE_MIN];
|
||
|
|
|
||
|
|
static int done = 0;
|
||
|
|
|
||
|
|
static WEBP_INLINE uint8_t clip(int v, int max_value) {
|
||
|
|
return v < 0 ? 0 : v > max_value ? max_value : v;
|
||
|
|
}
|
||
|
|
|
||
|
|
void VP8YUVInit(void) {
|
||
|
|
int i;
|
||
|
|
if (done) {
|
||
|
|
return;
|
||
|
|
}
|
||
|
|
for (i = 0; i < 256; ++i) {
|
||
|
|
VP8kVToR[i] = (89858 * (i - 128) + YUV_HALF) >> YUV_FIX;
|
||
|
|
VP8kUToG[i] = -22014 * (i - 128) + YUV_HALF;
|
||
|
|
VP8kVToG[i] = -45773 * (i - 128);
|
||
|
|
VP8kUToB[i] = (113618 * (i - 128) + YUV_HALF) >> YUV_FIX;
|
||
|
|
}
|
||
|
|
for (i = YUV_RANGE_MIN; i < YUV_RANGE_MAX; ++i) {
|
||
|
|
const int k = ((i - 16) * 76283 + YUV_HALF) >> YUV_FIX;
|
||
|
|
VP8kClip[i - YUV_RANGE_MIN] = clip(k, 255);
|
||
|
|
VP8kClip4Bits[i - YUV_RANGE_MIN] = clip((k + 8) >> 4, 15);
|
||
|
|
}
|
||
|
|
done = 1;
|
||
|
|
}
|
||
|
|
|
||
|
|
#if defined(__cplusplus) || defined(c_plusplus)
|
||
|
|
} // extern "C"
|
||
|
|
#endif
|