yuv.h
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- /* ***** BEGIN LICENSE BLOCK *****
- * Version: RCSL 1.0/RPSL 1.0
- *
- * Portions Copyright (c) 1995-2002 RealNetworks, Inc. All Rights Reserved.
- *
- * The contents of this file, and the files included with this file, are
- * subject to the current version of the RealNetworks Public Source License
- * Version 1.0 (the "RPSL") available at
- * http://www.helixcommunity.org/content/rpsl unless you have licensed
- * the file under the RealNetworks Community Source License Version 1.0
- * (the "RCSL") available at http://www.helixcommunity.org/content/rcsl,
- * in which case the RCSL will apply. You may also obtain the license terms
- * directly from RealNetworks. You may not use this file except in
- * compliance with the RPSL or, if you have a valid RCSL with RealNetworks
- * applicable to this file, the RCSL. Please see the applicable RPSL or
- * RCSL for the rights, obligations and limitations governing use of the
- * contents of the file.
- *
- * This file is part of the Helix DNA Technology. RealNetworks is the
- * developer of the Original Code and owns the copyrights in the portions
- * it created.
- *
- * This file, and the files included with this file, is distributed and made
- * available on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
- * EXPRESS OR IMPLIED, AND REALNETWORKS HEREBY DISCLAIMS ALL SUCH WARRANTIES,
- * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, FITNESS
- * FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
- *
- * Technology Compatibility Kit Test Suite(s) Location:
- * http://www.helixcommunity.org/content/tck
- *
- * Contributor(s):
- *
- * ***** END LICENSE BLOCK ***** */
- #ifndef __YUV_H__
- #define __YUV_H__ 1
- #ifdef __cplusplus
- extern "C" {
- #endif
- /*
- * This header contains a number of data declarations that supposed
- * to be shared between several modules. There should be only one module
- * that would own these data (i.e. declare them locally as public data),
- * while the others just should be able to access them (i.e. they would
- * need to see them declared as "extern"). The following macros would
- * allow us to combine both types of data declarations in a single place.
- */
- #ifndef YUV_MAIN
- #define YUV_EXTERN extern
- #else
- #define YUV_EXTERN /**/
- #endif
- /*
- * CCIR Rec. 601-2 definition of YCrCb color space.
- *
- * Given a primary analogue RGB signal (R,G,and B components are in the
- * range of 0..1 volt), the luminance signal is defined as:
- * Y = 0.299 R + 0.587 G + 0.114 B.
- * Signals of color-defferences, are therefore:
- * (R-Y) = 0.701 R - 0.587 G - 0.114 B, and
- * (B-Y) = -0.299 R - 0.587 G + 0.886 B.
- * Using normalization (we want (R-Y) and (B-Y) to be in the range of
- * -0.5..0.5 volt), we will obtain:
- * Cr = 0.5/0.701 (R-Y), and
- * Cb = 0.5/0.886 (B-Y).
- * Finally, the quantized versions of Y,Cr,and Cb are defined as:
- * Y' = 219 Y + 16,
- * Cr' = 224 Cr + 128, and
- * Cb' = 224 Cb + 128.
- * For convenience, we will use the following names for these constants
- * (here and below: V = Cr, and U = Cb):
- */
- #define CCIR601_YRCOEF 0.299
- #define CCIR601_YGCOEF 0.587
- #define CCIR601_YBCOEF 0.114
- #define CCIR601_YMAX 219
- #define CCIR601_YMED ((double)CCIR601_YMAX/2.)
- #define CCIR601_YOFFSET 16
- #define CCIR601_VMAX 224
- #define CCIR601_VOFFSET 128
- #define CCIR601_UMAX 224
- #define CCIR601_UOFFSET 128
- /*
- * Also, we typically will deal with quantized R'G'B' signal, represented
- * by 8-bit quantities for R', G' and B' components:
- */
- #define RGB_MAX ((1U << 8) - 1)
- /*
- * Forward R'G'B'->Y'Cr'Cb' conversion:
- * a) calculate Y":
- * Y" = 0.299 R' + 0.587 G' + 0.114 B'; => 3 muls/lookups
- * b) calculate Y',Cr',Cb' values:
- * Y' = 219/255 Y" + 16; => 1 mul/lookup
- * Cr' = 224/255 * 0.5/0.701 (R'-Y") + 128; => 1 mul/lookup
- * Cb' = 224/255 * 0.5/0.886 (B'-Y") + 128; => 1 mul/lookup
- */
- #define YSCALE ((double)CCIR601_YMAX/RGB_MAX)
- #define VSCALE ((double)CCIR601_VMAX/RGB_MAX * 0.5/(1.-CCIR601_YRCOEF))
- #define USCALE ((double)CCIR601_UMAX/RGB_MAX * 0.5/(1.-CCIR601_YBCOEF))
- #define YMAX (RGB_MAX + 3) /* include max. rounding error */
- #define VMAX (int)((double)(1.-CCIR601_YRCOEF) * RGB_MAX + 1)
- #define VMIN VMAX
- #define UMAX (int)((double)(1.-CCIR601_YBCOEF) * RGB_MAX + 1)
- #define UMIN UMAX
- /* R'G'B' -> Y'Cr'Cb' conversion tables: */
- YUV_EXTERN int yrtab [RGB_MAX+1], ygtab [RGB_MAX+1], ybtab [RGB_MAX+1];
- YUV_EXTERN int yytab [YMAX+1], vrytab [VMIN+VMAX+1], ubytab [UMIN+UMAX+1];
- /*
- * Backward Y'Cr'Cb'->R'G'B' conversion:
- * a) calculate Y":
- * Y" = 1/(219/255) (Y'-16); => 1 mul/lookup
- * b) calculate R'B':
- * R' = Y" + 1/(224/255 * 0.5/0.701) (Cr'-128); => 1 mul/lookup
- * B' = Y" + 1/(224/255 * 0.5/0.886) (Cb'-128); => 1 mul/lookup
- * c) calculate G':
- * G' = 1/0.587 (Y" - 0.299 R' - 0.114 B') =
- * = Y" - 0.299/0.587/(224/255 * 0.5/0.701) (Cr'-128)
- * - 0.114/0.587/(224/255 * 0.5/0.886) (Cb'-128); => 2 muls/luts
- */
- #define YCOEF (1/YSCALE)
- #define RVCOEF (1/VSCALE)
- #define GVCOEF (-CCIR601_YRCOEF/CCIR601_YGCOEF/VSCALE)
- #define GUCOEF (-CCIR601_YBCOEF/CCIR601_YGCOEF/USCALE)
- #define BUCOEF (1/USCALE)
- /* Y'Cr'Cb'->R'G'B' conversion tables: */
- YUV_EXTERN int ytab [RGB_MAX+1], rvtab [RGB_MAX+1], gvtab [RGB_MAX+1];
- YUV_EXTERN int gutab [RGB_MAX+1], butab [RGB_MAX+1];
- YUV_EXTERN int rutab [RGB_MAX+1], bvtab [RGB_MAX+1]; /* alpha != 0 */
- /*
- * Color adjustments.
- * a) hue: in NTSC YUV color space, the hue adjustment is equivalent
- * to the UV axes rotation:
- * V' = V cos(alpha) - U sin(alpha);
- * U' = V sin(alpha) + U cos(alpha);
- * where:
- * V = (R-Y)/1.14;
- * U = (B-Y)/2.03;
- * In YCrCb color space, this will be equivalent to:
- * Cr' - 128 = (Cr - 128) cos(alpha) - zeta (Cb - 128) sin(alpha));.
- * Cb' - 128 = xi (Cr - 128) sin(alpha) + (Cb - 128) cos(alpha);
- * where:
- * xi = (1./(0.5/0.701)/1.14)/(1./(0.5/0.886)/2.03);
- * zeta = 1/xi;
- * b) saturation:
- * Cr' - 128 = beta (Cr - 128);
- * Cb' - 128 = beta (Cb - 128);
- * c) brightness:
- * Y' - 16 = gamma (Y - 16);
- * Cr' - 128 = gamma (Cr - 128);
- * Cb' - 128 = gamma (Cb - 128);
- * d) contrast:
- * Y' - 16 = lambda + kappa (Y - 16);
- * e) all together:
- * Y' - 16 = gamma (lambda + kappa (Y - 16));
- * Cr' - 128 = gamma beta ((Cr - 128) cos(alpha) - zeta (Cb - 128) sin(alpha));
- * Cb' - 128 = gamma beta (xi (Cr - 128) sin(alpha) + (Cb - 128) cos(alpha));
- */
- #define XI (((1.-CCIR601_YRCOEF)/0.5/1.14)/((1.-CCIR601_YBCOEF)/0.5/2.03))
- #define ZETA (1./XI)
- /* empirically choosen limits for color adjustments: */
- #define ALPHA_MAX (M_PI*3/4)
- #define ALPHA_MED 0. /* hue */
- #define ALPHA_MIN (-M_PI*3/4)
- #define BETA_MAX M_SQRT2
- #define BETA_MED 1. /* saturation */
- #define BETA_MIN (M_SQRT2/4)
- #define GAMMA_MAX M_SQRT2
- #define GAMMA_MED 1. /* brightness */
- #define GAMMA_MIN 0.5
- #define KAPPA_MIN 0.5
- #define KAPPA_MED 1. /* contrast */
- #define KAPPA_MAX 2.
- #define LAMBDA(kappa) (CCIR601_YMED * (1. - kappa))
- /* indicators of current color adjustment coefficients: */
- YUV_EXTERN int is_alpha, is_beta, is_gamma, is_kappa;
- /* Y'Cr'Cb'->Y'Cr'Cb' conversion tables: */
- YUV_EXTERN int _yytab [RGB_MAX+1], _uutab [RGB_MAX+1], _vvtab [RGB_MAX+1];
- YUV_EXTERN int _uvtab [RGB_MAX+1], _vutab [RGB_MAX+1]; /* alpha != 0: */
- /* chroma resampling mode: */
- YUV_EXTERN int chroma_resampling_mode;
- #ifdef __cplusplus
- }
- #endif
- #endif /* __YUV_H__ */