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Diffstat (limited to 'converter/ppm/ppmtompeg/rgbtoycc.c')
| -rw-r--r-- | converter/ppm/ppmtompeg/rgbtoycc.c | 204 |
1 files changed, 204 insertions, 0 deletions
diff --git a/converter/ppm/ppmtompeg/rgbtoycc.c b/converter/ppm/ppmtompeg/rgbtoycc.c new file mode 100644 index 00000000..766b8902 --- /dev/null +++ b/converter/ppm/ppmtompeg/rgbtoycc.c @@ -0,0 +1,204 @@ +/*===========================================================================* + * rgbtoycc.c * + * * + * Procedures to convert from RGB space to YUV space * + * * + * EXPORTED PROCEDURES: * + * PNMtoYUV * + * PPMtoYUV * + * * + *===========================================================================*/ + +/* + * Copyright (c) 1995 The Regents of the University of California. + * All rights reserved. + * + * Permission to use, copy, modify, and distribute this software and its + * documentation for any purpose, without fee, and without written agreement is + * hereby granted, provided that the above copyright notice and the following + * two paragraphs appear in all copies of this software. + * + * IN NO EVENT SHALL THE UNIVERSITY OF CALIFORNIA BE LIABLE TO ANY PARTY FOR + * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES ARISING OUT + * OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN IF THE UNIVERSITY OF + * CALIFORNIA HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + * + * THE UNIVERSITY OF CALIFORNIA SPECIFICALLY DISCLAIMS ANY WARRANTIES, + * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY + * AND FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS + * ON AN "AS IS" BASIS, AND THE UNIVERSITY OF CALIFORNIA HAS NO OBLIGATION TO + * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS. + */ + +/*==============* + * HEADER FILES * + *==============*/ + +#include "pnm.h" +#include "all.h" +#include "frame.h" +#include "rgbtoycc.h" + + +static float *mult299, *mult587, *mult114, *mult16874, *mult33126, + *mult5, *mult41869, *mult08131; /* malloc'ed */ + /* These are tables we use for fast arithmetic */ +static pixval table_maxval = 0; + /* The maxval used to compute the above arrays. Zero means + the above arrays don't exist yet + */ + +static void +compute_mult_tables(const pixval maxval) { + + /* For speed, we do the arithmetic with eight tables that reduce a + bunch of multiplications and divisions to a simple table lookup. + + Because a large maxval could require a significant amount of + table space, we allocate the space dynamically. + + If we had to compute the tables for every frame, it wouldn't be + fast at all, but since all the frames normally have the same + maxval, we only need to compute them once. But just in case, + we check each frame to see if it has a different maxval and + recompute the tables if so. + */ + + if (table_maxval != maxval) { + /* We need to compute or re-compute the multiplication tables */ + if (table_maxval != 0) { + free(mult299); free(mult587); free(mult114); free(mult16874); + free(mult33126); free(mult5); free(mult41869); free(mult08131); + } + table_maxval = maxval; + + mult299 = malloc((table_maxval+1)*sizeof(float)); + mult587 = malloc((table_maxval+1)*sizeof(float)); + mult114 = malloc((table_maxval+1)*sizeof(float)); + mult16874 = malloc((table_maxval+1)*sizeof(float)); + mult33126 = malloc((table_maxval+1)*sizeof(float)); + mult5 = malloc((table_maxval+1)*sizeof(float)); + mult41869 = malloc((table_maxval+1)*sizeof(float)); + mult08131 = malloc((table_maxval+1)*sizeof(float)); + + if (mult299 == NULL || mult587 == NULL || mult114 == NULL || + mult16874 == NULL || mult33126 == NULL || mult5 == NULL || + mult41869 == NULL || mult08131 == NULL) + pm_error("Unable to allocate storage for arithmetic tables.\n" + "We need %d bytes, which is the maxval of the input " + "image, plus 1,\n" + "times the storage size of a floating point value.", + 8 * (table_maxval+1)*sizeof(float)); + + { + int index; + + for (index = 0; index <= table_maxval; index++ ) { + mult299[index] = index*0.29900 * 255 / table_maxval; + mult587[index] = index*0.58700 * 255 / table_maxval; + mult114[index] = index*0.11400 * 255 / table_maxval; + mult16874[index] = -0.16874*index * 255 / table_maxval; + mult33126[index] = -0.33126*index * 255 / table_maxval; + mult5[index] = index*0.50000 * 255 / table_maxval; + mult41869[index] = -0.41869*index * 255 / table_maxval; + mult08131[index] = -0.08131*index * 255 / table_maxval; + } + } + } +} + + +/*=====================* + * EXPORTED PROCEDURES * + *=====================*/ + + +void +PNMtoYUV(MpegFrame * const frameP, + xel ** const xels, + unsigned int const cols, + unsigned int const rows, + xelval const maxval) { +/*---------------------------------------------------------------------------- + Set the raster of the MPEG frame *frameP from the libnetpbm input + 'xels'. Note that the raster information in a MpegFrame is in YUV + form. +-----------------------------------------------------------------------------*/ + int x, y; + uint8 *dy0, *dy1; + uint8 *dcr, *dcb; + pixel *src0, *src1; + + compute_mult_tables(maxval); /* This sets up mult299[], etc. */ + + Frame_AllocYCC(frameP); + + /* + * okay. Now, convert everything into YCbCr space. (the specific + * numbers come from the JPEG source, jccolor.c) The conversion + * equations to be implemented are therefore + * + * Y = 0.29900 * R + 0.58700 * G + 0.11400 * B + * Cb = -0.16874 * R - 0.33126 * G + 0.50000 * B + * Cr = 0.50000 * R - 0.41869 * G - 0.08131 * B + * + * With Y, Cb, and Cr then normalized to the range 0 - 255. + */ + + for (y = 0; y < rows; y += 2) { + for (x = 0, src0 = xels[y], src1 = xels[y + 1], + dy0 = frameP->orig_y[y], dy1 = frameP->orig_y[y + 1], + dcr = frameP->orig_cr[y >> 1], dcb = frameP->orig_cb[y >> 1]; + x < cols; + x += 2, dy0 += 2, dy1 += 2, dcr++, + dcb++, src0 += 2, src1 += 2) { + + *dy0 = (mult299[PPM_GETR(*src0)] + + mult587[PPM_GETG(*src0)] + + mult114[PPM_GETB(*src0)]); + + *dy1 = (mult299[PPM_GETR(*src1)] + + mult587[PPM_GETG(*src1)] + + mult114[PPM_GETB(*src1)]); + + dy0[1] = (mult299[PPM_GETR(src0[1])] + + mult587[PPM_GETG(src0[1])] + + mult114[PPM_GETB(src0[1])]); + + dy1[1] = (mult299[PPM_GETR(src1[1])] + + mult587[PPM_GETG(src1[1])] + + mult114[PPM_GETB(src1[1])]); + + *dcb = ((mult16874[PPM_GETR(*src0)] + + mult33126[PPM_GETG(*src0)] + + mult5[PPM_GETB(*src0)] + + mult16874[PPM_GETR(*src1)] + + mult33126[PPM_GETG(*src1)] + + mult5[PPM_GETB(*src1)] + + mult16874[PPM_GETR(src0[1])] + + mult33126[PPM_GETG(src0[1])] + + mult5[PPM_GETB(src0[1])] + + mult16874[PPM_GETR(src1[1])] + + mult33126[PPM_GETG(src1[1])] + + mult5[PPM_GETB(src1[1])]) / 4) + 128; + + *dcr = ((mult5[PPM_GETR(*src0)] + + mult41869[PPM_GETG(*src0)] + + mult08131[PPM_GETB(*src0)] + + mult5[PPM_GETR(*src1)] + + mult41869[PPM_GETG(*src1)] + + mult08131[PPM_GETB(*src1)] + + mult5[PPM_GETR(src0[1])] + + mult41869[PPM_GETG(src0[1])] + + mult08131[PPM_GETB(src0[1])] + + mult5[PPM_GETR(src1[1])] + + mult41869[PPM_GETG(src1[1])] + + mult08131[PPM_GETB(src1[1])]) / 4) + 128; + + DBG_PRINT(("%3d,%3d: (%3d,%3d,%3d) --> (%3d,%3d,%3d)\n", + x, y, + PPM_GETR(*src0), PPM_GETG(*src0), PPM_GETB(*src0), + *dy0, *dcb, *dcr)); + } + } +} |