mirror of
https://github.com/opencv/opencv.git
synced 2024-11-29 22:00:25 +08:00
76 lines
2.1 KiB
C
76 lines
2.1 KiB
C
// Copyright 2010 Google Inc. All Rights Reserved.
|
|
//
|
|
// Use of this source code is governed by a BSD-style license
|
|
// that can be found in the COPYING file in the root of the source
|
|
// tree. An additional intellectual property rights grant can be found
|
|
// in the file PATENTS. All contributing project authors may
|
|
// be found in the AUTHORS file in the root of the source tree.
|
|
// -----------------------------------------------------------------------------
|
|
//
|
|
// YUV->RGB conversion function
|
|
//
|
|
// Author: Skal (pascal.massimino@gmail.com)
|
|
|
|
#include "./yuv.h"
|
|
|
|
#if defined(__cplusplus) || defined(c_plusplus)
|
|
extern "C" {
|
|
#endif
|
|
|
|
#ifdef WEBP_YUV_USE_TABLE
|
|
|
|
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;
|
|
}
|
|
#ifndef USE_YUVj
|
|
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);
|
|
}
|
|
#else
|
|
for (i = 0; i < 256; ++i) {
|
|
VP8kVToR[i] = (91881 * (i - 128) + YUV_HALF) >> YUV_FIX;
|
|
VP8kUToG[i] = -22554 * (i - 128) + YUV_HALF;
|
|
VP8kVToG[i] = -46802 * (i - 128);
|
|
VP8kUToB[i] = (116130 * (i - 128) + YUV_HALF) >> YUV_FIX;
|
|
}
|
|
for (i = YUV_RANGE_MIN; i < YUV_RANGE_MAX; ++i) {
|
|
const int k = i;
|
|
VP8kClip[i - YUV_RANGE_MIN] = clip(k, 255);
|
|
VP8kClip4Bits[i - YUV_RANGE_MIN] = clip((k + 8) >> 4, 15);
|
|
}
|
|
#endif
|
|
|
|
done = 1;
|
|
}
|
|
|
|
#else
|
|
|
|
void VP8YUVInit(void) {}
|
|
|
|
#endif // WEBP_YUV_USE_TABLE
|
|
|
|
#if defined(__cplusplus) || defined(c_plusplus)
|
|
} // extern "C"
|
|
#endif
|