1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/media/libpng/pngwtran.c Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,572 @@
1.4 +
1.5 +/* pngwtran.c - transforms the data in a row for PNG writers
1.6 + *
1.7 + * Last changed in libpng 1.6.9 [February 6, 2014]
1.8 + * Copyright (c) 1998-2014 Glenn Randers-Pehrson
1.9 + * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
1.10 + * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
1.11 + *
1.12 + * This code is released under the libpng license.
1.13 + * For conditions of distribution and use, see the disclaimer
1.14 + * and license in png.h
1.15 + */
1.16 +
1.17 +#include "pngpriv.h"
1.18 +
1.19 +#ifdef PNG_WRITE_SUPPORTED
1.20 +#ifdef PNG_WRITE_TRANSFORMS_SUPPORTED
1.21 +
1.22 +#ifdef PNG_WRITE_PACK_SUPPORTED
1.23 +/* Pack pixels into bytes. Pass the true bit depth in bit_depth. The
1.24 + * row_info bit depth should be 8 (one pixel per byte). The channels
1.25 + * should be 1 (this only happens on grayscale and paletted images).
1.26 + */
1.27 +static void
1.28 +png_do_pack(png_row_infop row_info, png_bytep row, png_uint_32 bit_depth)
1.29 +{
1.30 + png_debug(1, "in png_do_pack");
1.31 +
1.32 + if (row_info->bit_depth == 8 &&
1.33 + row_info->channels == 1)
1.34 + {
1.35 + switch ((int)bit_depth)
1.36 + {
1.37 + case 1:
1.38 + {
1.39 + png_bytep sp, dp;
1.40 + int mask, v;
1.41 + png_uint_32 i;
1.42 + png_uint_32 row_width = row_info->width;
1.43 +
1.44 + sp = row;
1.45 + dp = row;
1.46 + mask = 0x80;
1.47 + v = 0;
1.48 +
1.49 + for (i = 0; i < row_width; i++)
1.50 + {
1.51 + if (*sp != 0)
1.52 + v |= mask;
1.53 +
1.54 + sp++;
1.55 +
1.56 + if (mask > 1)
1.57 + mask >>= 1;
1.58 +
1.59 + else
1.60 + {
1.61 + mask = 0x80;
1.62 + *dp = (png_byte)v;
1.63 + dp++;
1.64 + v = 0;
1.65 + }
1.66 + }
1.67 +
1.68 + if (mask != 0x80)
1.69 + *dp = (png_byte)v;
1.70 +
1.71 + break;
1.72 + }
1.73 +
1.74 + case 2:
1.75 + {
1.76 + png_bytep sp, dp;
1.77 + int shift, v;
1.78 + png_uint_32 i;
1.79 + png_uint_32 row_width = row_info->width;
1.80 +
1.81 + sp = row;
1.82 + dp = row;
1.83 + shift = 6;
1.84 + v = 0;
1.85 +
1.86 + for (i = 0; i < row_width; i++)
1.87 + {
1.88 + png_byte value;
1.89 +
1.90 + value = (png_byte)(*sp & 0x03);
1.91 + v |= (value << shift);
1.92 +
1.93 + if (shift == 0)
1.94 + {
1.95 + shift = 6;
1.96 + *dp = (png_byte)v;
1.97 + dp++;
1.98 + v = 0;
1.99 + }
1.100 +
1.101 + else
1.102 + shift -= 2;
1.103 +
1.104 + sp++;
1.105 + }
1.106 +
1.107 + if (shift != 6)
1.108 + *dp = (png_byte)v;
1.109 +
1.110 + break;
1.111 + }
1.112 +
1.113 + case 4:
1.114 + {
1.115 + png_bytep sp, dp;
1.116 + int shift, v;
1.117 + png_uint_32 i;
1.118 + png_uint_32 row_width = row_info->width;
1.119 +
1.120 + sp = row;
1.121 + dp = row;
1.122 + shift = 4;
1.123 + v = 0;
1.124 +
1.125 + for (i = 0; i < row_width; i++)
1.126 + {
1.127 + png_byte value;
1.128 +
1.129 + value = (png_byte)(*sp & 0x0f);
1.130 + v |= (value << shift);
1.131 +
1.132 + if (shift == 0)
1.133 + {
1.134 + shift = 4;
1.135 + *dp = (png_byte)v;
1.136 + dp++;
1.137 + v = 0;
1.138 + }
1.139 +
1.140 + else
1.141 + shift -= 4;
1.142 +
1.143 + sp++;
1.144 + }
1.145 +
1.146 + if (shift != 4)
1.147 + *dp = (png_byte)v;
1.148 +
1.149 + break;
1.150 + }
1.151 +
1.152 + default:
1.153 + break;
1.154 + }
1.155 +
1.156 + row_info->bit_depth = (png_byte)bit_depth;
1.157 + row_info->pixel_depth = (png_byte)(bit_depth * row_info->channels);
1.158 + row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth,
1.159 + row_info->width);
1.160 + }
1.161 +}
1.162 +#endif
1.163 +
1.164 +#ifdef PNG_WRITE_SHIFT_SUPPORTED
1.165 +/* Shift pixel values to take advantage of whole range. Pass the
1.166 + * true number of bits in bit_depth. The row should be packed
1.167 + * according to row_info->bit_depth. Thus, if you had a row of
1.168 + * bit depth 4, but the pixels only had values from 0 to 7, you
1.169 + * would pass 3 as bit_depth, and this routine would translate the
1.170 + * data to 0 to 15.
1.171 + */
1.172 +static void
1.173 +png_do_shift(png_row_infop row_info, png_bytep row,
1.174 + png_const_color_8p bit_depth)
1.175 +{
1.176 + png_debug(1, "in png_do_shift");
1.177 +
1.178 + if (row_info->color_type != PNG_COLOR_TYPE_PALETTE)
1.179 + {
1.180 + int shift_start[4], shift_dec[4];
1.181 + int channels = 0;
1.182 +
1.183 + if (row_info->color_type & PNG_COLOR_MASK_COLOR)
1.184 + {
1.185 + shift_start[channels] = row_info->bit_depth - bit_depth->red;
1.186 + shift_dec[channels] = bit_depth->red;
1.187 + channels++;
1.188 +
1.189 + shift_start[channels] = row_info->bit_depth - bit_depth->green;
1.190 + shift_dec[channels] = bit_depth->green;
1.191 + channels++;
1.192 +
1.193 + shift_start[channels] = row_info->bit_depth - bit_depth->blue;
1.194 + shift_dec[channels] = bit_depth->blue;
1.195 + channels++;
1.196 + }
1.197 +
1.198 + else
1.199 + {
1.200 + shift_start[channels] = row_info->bit_depth - bit_depth->gray;
1.201 + shift_dec[channels] = bit_depth->gray;
1.202 + channels++;
1.203 + }
1.204 +
1.205 + if (row_info->color_type & PNG_COLOR_MASK_ALPHA)
1.206 + {
1.207 + shift_start[channels] = row_info->bit_depth - bit_depth->alpha;
1.208 + shift_dec[channels] = bit_depth->alpha;
1.209 + channels++;
1.210 + }
1.211 +
1.212 + /* With low row depths, could only be grayscale, so one channel */
1.213 + if (row_info->bit_depth < 8)
1.214 + {
1.215 + png_bytep bp = row;
1.216 + png_size_t i;
1.217 + unsigned int mask;
1.218 + png_size_t row_bytes = row_info->rowbytes;
1.219 +
1.220 + if (bit_depth->gray == 1 && row_info->bit_depth == 2)
1.221 + mask = 0x55;
1.222 +
1.223 + else if (row_info->bit_depth == 4 && bit_depth->gray == 3)
1.224 + mask = 0x11;
1.225 +
1.226 + else
1.227 + mask = 0xff;
1.228 +
1.229 + for (i = 0; i < row_bytes; i++, bp++)
1.230 + {
1.231 + int j;
1.232 + unsigned int v, out;
1.233 +
1.234 + v = *bp;
1.235 + out = 0;
1.236 +
1.237 + for (j = shift_start[0]; j > -shift_dec[0]; j -= shift_dec[0])
1.238 + {
1.239 + if (j > 0)
1.240 + out |= v << j;
1.241 +
1.242 + else
1.243 + out |= (v >> (-j)) & mask;
1.244 + }
1.245 +
1.246 + *bp = (png_byte)(out & 0xff);
1.247 + }
1.248 + }
1.249 +
1.250 + else if (row_info->bit_depth == 8)
1.251 + {
1.252 + png_bytep bp = row;
1.253 + png_uint_32 i;
1.254 + png_uint_32 istop = channels * row_info->width;
1.255 +
1.256 + for (i = 0; i < istop; i++, bp++)
1.257 + {
1.258 +
1.259 + const unsigned int c = i%channels;
1.260 + int j;
1.261 + unsigned int v, out;
1.262 +
1.263 + v = *bp;
1.264 + out = 0;
1.265 +
1.266 + for (j = shift_start[c]; j > -shift_dec[c]; j -= shift_dec[c])
1.267 + {
1.268 + if (j > 0)
1.269 + out |= v << j;
1.270 +
1.271 + else
1.272 + out |= v >> (-j);
1.273 + }
1.274 +
1.275 + *bp = (png_byte)(out & 0xff);
1.276 + }
1.277 + }
1.278 +
1.279 + else
1.280 + {
1.281 + png_bytep bp;
1.282 + png_uint_32 i;
1.283 + png_uint_32 istop = channels * row_info->width;
1.284 +
1.285 + for (bp = row, i = 0; i < istop; i++)
1.286 + {
1.287 + const unsigned int c = i%channels;
1.288 + int j;
1.289 + unsigned int value, v;
1.290 +
1.291 + v = png_get_uint_16(bp);
1.292 + value = 0;
1.293 +
1.294 + for (j = shift_start[c]; j > -shift_dec[c]; j -= shift_dec[c])
1.295 + {
1.296 + if (j > 0)
1.297 + value |= v << j;
1.298 +
1.299 + else
1.300 + value |= v >> (-j);
1.301 + }
1.302 + *bp++ = (png_byte)((value >> 8) & 0xff);
1.303 + *bp++ = (png_byte)(value & 0xff);
1.304 + }
1.305 + }
1.306 + }
1.307 +}
1.308 +#endif
1.309 +
1.310 +#ifdef PNG_WRITE_SWAP_ALPHA_SUPPORTED
1.311 +static void
1.312 +png_do_write_swap_alpha(png_row_infop row_info, png_bytep row)
1.313 +{
1.314 + png_debug(1, "in png_do_write_swap_alpha");
1.315 +
1.316 + {
1.317 + if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
1.318 + {
1.319 + if (row_info->bit_depth == 8)
1.320 + {
1.321 + /* This converts from ARGB to RGBA */
1.322 + png_bytep sp, dp;
1.323 + png_uint_32 i;
1.324 + png_uint_32 row_width = row_info->width;
1.325 +
1.326 + for (i = 0, sp = dp = row; i < row_width; i++)
1.327 + {
1.328 + png_byte save = *(sp++);
1.329 + *(dp++) = *(sp++);
1.330 + *(dp++) = *(sp++);
1.331 + *(dp++) = *(sp++);
1.332 + *(dp++) = save;
1.333 + }
1.334 + }
1.335 +
1.336 +#ifdef PNG_WRITE_16BIT_SUPPORTED
1.337 + else
1.338 + {
1.339 + /* This converts from AARRGGBB to RRGGBBAA */
1.340 + png_bytep sp, dp;
1.341 + png_uint_32 i;
1.342 + png_uint_32 row_width = row_info->width;
1.343 +
1.344 + for (i = 0, sp = dp = row; i < row_width; i++)
1.345 + {
1.346 + png_byte save[2];
1.347 + save[0] = *(sp++);
1.348 + save[1] = *(sp++);
1.349 + *(dp++) = *(sp++);
1.350 + *(dp++) = *(sp++);
1.351 + *(dp++) = *(sp++);
1.352 + *(dp++) = *(sp++);
1.353 + *(dp++) = *(sp++);
1.354 + *(dp++) = *(sp++);
1.355 + *(dp++) = save[0];
1.356 + *(dp++) = save[1];
1.357 + }
1.358 + }
1.359 +#endif /* PNG_WRITE_16BIT_SUPPORTED */
1.360 + }
1.361 +
1.362 + else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
1.363 + {
1.364 + if (row_info->bit_depth == 8)
1.365 + {
1.366 + /* This converts from AG to GA */
1.367 + png_bytep sp, dp;
1.368 + png_uint_32 i;
1.369 + png_uint_32 row_width = row_info->width;
1.370 +
1.371 + for (i = 0, sp = dp = row; i < row_width; i++)
1.372 + {
1.373 + png_byte save = *(sp++);
1.374 + *(dp++) = *(sp++);
1.375 + *(dp++) = save;
1.376 + }
1.377 + }
1.378 +
1.379 +#ifdef PNG_WRITE_16BIT_SUPPORTED
1.380 + else
1.381 + {
1.382 + /* This converts from AAGG to GGAA */
1.383 + png_bytep sp, dp;
1.384 + png_uint_32 i;
1.385 + png_uint_32 row_width = row_info->width;
1.386 +
1.387 + for (i = 0, sp = dp = row; i < row_width; i++)
1.388 + {
1.389 + png_byte save[2];
1.390 + save[0] = *(sp++);
1.391 + save[1] = *(sp++);
1.392 + *(dp++) = *(sp++);
1.393 + *(dp++) = *(sp++);
1.394 + *(dp++) = save[0];
1.395 + *(dp++) = save[1];
1.396 + }
1.397 + }
1.398 +#endif /* PNG_WRITE_16BIT_SUPPORTED */
1.399 + }
1.400 + }
1.401 +}
1.402 +#endif
1.403 +
1.404 +#ifdef PNG_WRITE_INVERT_ALPHA_SUPPORTED
1.405 +static void
1.406 +png_do_write_invert_alpha(png_row_infop row_info, png_bytep row)
1.407 +{
1.408 + png_debug(1, "in png_do_write_invert_alpha");
1.409 +
1.410 + {
1.411 + if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
1.412 + {
1.413 + if (row_info->bit_depth == 8)
1.414 + {
1.415 + /* This inverts the alpha channel in RGBA */
1.416 + png_bytep sp, dp;
1.417 + png_uint_32 i;
1.418 + png_uint_32 row_width = row_info->width;
1.419 +
1.420 + for (i = 0, sp = dp = row; i < row_width; i++)
1.421 + {
1.422 + /* Does nothing
1.423 + *(dp++) = *(sp++);
1.424 + *(dp++) = *(sp++);
1.425 + *(dp++) = *(sp++);
1.426 + */
1.427 + sp+=3; dp = sp;
1.428 + *(dp++) = (png_byte)(255 - *(sp++));
1.429 + }
1.430 + }
1.431 +
1.432 +#ifdef PNG_WRITE_16BIT_SUPPORTED
1.433 + else
1.434 + {
1.435 + /* This inverts the alpha channel in RRGGBBAA */
1.436 + png_bytep sp, dp;
1.437 + png_uint_32 i;
1.438 + png_uint_32 row_width = row_info->width;
1.439 +
1.440 + for (i = 0, sp = dp = row; i < row_width; i++)
1.441 + {
1.442 + /* Does nothing
1.443 + *(dp++) = *(sp++);
1.444 + *(dp++) = *(sp++);
1.445 + *(dp++) = *(sp++);
1.446 + *(dp++) = *(sp++);
1.447 + *(dp++) = *(sp++);
1.448 + *(dp++) = *(sp++);
1.449 + */
1.450 + sp+=6; dp = sp;
1.451 + *(dp++) = (png_byte)(255 - *(sp++));
1.452 + *(dp++) = (png_byte)(255 - *(sp++));
1.453 + }
1.454 + }
1.455 +#endif /* PNG_WRITE_16BIT_SUPPORTED */
1.456 + }
1.457 +
1.458 + else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
1.459 + {
1.460 + if (row_info->bit_depth == 8)
1.461 + {
1.462 + /* This inverts the alpha channel in GA */
1.463 + png_bytep sp, dp;
1.464 + png_uint_32 i;
1.465 + png_uint_32 row_width = row_info->width;
1.466 +
1.467 + for (i = 0, sp = dp = row; i < row_width; i++)
1.468 + {
1.469 + *(dp++) = *(sp++);
1.470 + *(dp++) = (png_byte)(255 - *(sp++));
1.471 + }
1.472 + }
1.473 +
1.474 +#ifdef PNG_WRITE_16BIT_SUPPORTED
1.475 + else
1.476 + {
1.477 + /* This inverts the alpha channel in GGAA */
1.478 + png_bytep sp, dp;
1.479 + png_uint_32 i;
1.480 + png_uint_32 row_width = row_info->width;
1.481 +
1.482 + for (i = 0, sp = dp = row; i < row_width; i++)
1.483 + {
1.484 + /* Does nothing
1.485 + *(dp++) = *(sp++);
1.486 + *(dp++) = *(sp++);
1.487 + */
1.488 + sp+=2; dp = sp;
1.489 + *(dp++) = (png_byte)(255 - *(sp++));
1.490 + *(dp++) = (png_byte)(255 - *(sp++));
1.491 + }
1.492 + }
1.493 +#endif /* PNG_WRITE_16BIT_SUPPORTED */
1.494 + }
1.495 + }
1.496 +}
1.497 +#endif
1.498 +
1.499 +/* Transform the data according to the user's wishes. The order of
1.500 + * transformations is significant.
1.501 + */
1.502 +void /* PRIVATE */
1.503 +png_do_write_transformations(png_structrp png_ptr, png_row_infop row_info)
1.504 +{
1.505 + png_debug(1, "in png_do_write_transformations");
1.506 +
1.507 + if (png_ptr == NULL)
1.508 + return;
1.509 +
1.510 +#ifdef PNG_WRITE_USER_TRANSFORM_SUPPORTED
1.511 + if (png_ptr->transformations & PNG_USER_TRANSFORM)
1.512 + if (png_ptr->write_user_transform_fn != NULL)
1.513 + (*(png_ptr->write_user_transform_fn)) /* User write transform
1.514 + function */
1.515 + (png_ptr, /* png_ptr */
1.516 + row_info, /* row_info: */
1.517 + /* png_uint_32 width; width of row */
1.518 + /* png_size_t rowbytes; number of bytes in row */
1.519 + /* png_byte color_type; color type of pixels */
1.520 + /* png_byte bit_depth; bit depth of samples */
1.521 + /* png_byte channels; number of channels (1-4) */
1.522 + /* png_byte pixel_depth; bits per pixel (depth*channels) */
1.523 + png_ptr->row_buf + 1); /* start of pixel data for row */
1.524 +#endif
1.525 +
1.526 +#ifdef PNG_WRITE_FILLER_SUPPORTED
1.527 + if (png_ptr->transformations & PNG_FILLER)
1.528 + png_do_strip_channel(row_info, png_ptr->row_buf + 1,
1.529 + !(png_ptr->flags & PNG_FLAG_FILLER_AFTER));
1.530 +#endif
1.531 +
1.532 +#ifdef PNG_WRITE_PACKSWAP_SUPPORTED
1.533 + if (png_ptr->transformations & PNG_PACKSWAP)
1.534 + png_do_packswap(row_info, png_ptr->row_buf + 1);
1.535 +#endif
1.536 +
1.537 +#ifdef PNG_WRITE_PACK_SUPPORTED
1.538 + if (png_ptr->transformations & PNG_PACK)
1.539 + png_do_pack(row_info, png_ptr->row_buf + 1,
1.540 + (png_uint_32)png_ptr->bit_depth);
1.541 +#endif
1.542 +
1.543 +#ifdef PNG_WRITE_SWAP_SUPPORTED
1.544 + if (png_ptr->transformations & PNG_SWAP_BYTES)
1.545 + png_do_swap(row_info, png_ptr->row_buf + 1);
1.546 +#endif
1.547 +
1.548 +#ifdef PNG_WRITE_SHIFT_SUPPORTED
1.549 + if (png_ptr->transformations & PNG_SHIFT)
1.550 + png_do_shift(row_info, png_ptr->row_buf + 1,
1.551 + &(png_ptr->shift));
1.552 +#endif
1.553 +
1.554 +#ifdef PNG_WRITE_SWAP_ALPHA_SUPPORTED
1.555 + if (png_ptr->transformations & PNG_SWAP_ALPHA)
1.556 + png_do_write_swap_alpha(row_info, png_ptr->row_buf + 1);
1.557 +#endif
1.558 +
1.559 +#ifdef PNG_WRITE_INVERT_ALPHA_SUPPORTED
1.560 + if (png_ptr->transformations & PNG_INVERT_ALPHA)
1.561 + png_do_write_invert_alpha(row_info, png_ptr->row_buf + 1);
1.562 +#endif
1.563 +
1.564 +#ifdef PNG_WRITE_BGR_SUPPORTED
1.565 + if (png_ptr->transformations & PNG_BGR)
1.566 + png_do_bgr(row_info, png_ptr->row_buf + 1);
1.567 +#endif
1.568 +
1.569 +#ifdef PNG_WRITE_INVERT_SUPPORTED
1.570 + if (png_ptr->transformations & PNG_INVERT_MONO)
1.571 + png_do_invert(row_info, png_ptr->row_buf + 1);
1.572 +#endif
1.573 +}
1.574 +#endif /* PNG_WRITE_TRANSFORMS_SUPPORTED */
1.575 +#endif /* PNG_WRITE_SUPPORTED */
