| /* |
| * Small jpeg decoder library |
| * |
| * Copyright (c) 2006, Luc Saillard <luc@saillard.org> |
| * All rights reserved. |
| * Redistribution and use in source and binary forms, with or without |
| * modification, are permitted provided that the following conditions are met: |
| * |
| * - Redistributions of source code must retain the above copyright notice, |
| * this list of conditions and the following disclaimer. |
| * |
| * - Redistributions in binary form must reproduce the above copyright notice, |
| * this list of conditions and the following disclaimer in the documentation |
| * and/or other materials provided with the distribution. |
| * |
| * - Neither the name of the author nor the names of its contributors may be |
| * used to endorse or promote products derived from this software without |
| * specific prior written permission. |
| * |
| * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" |
| * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
| * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
| * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE |
| * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR |
| * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF |
| * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS |
| * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN |
| * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) |
| * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE |
| * POSSIBILITY OF SUCH DAMAGE. |
| * |
| */ |
| |
| #include <stdio.h> |
| #include <stdlib.h> |
| #include <string.h> |
| #include <stdint.h> |
| |
| #include "tinyjpeg.h" |
| #include "tinyjpeg-internal.h" |
| |
| /** |
| * YCrCb -> Grey (1x1, 1x2) |
| * .---. |
| * | 1 | |
| * `---' |
| */ |
| static void YCrCB_to_Grey_1xN(struct jdec_private *priv, int sx, int sy) |
| { |
| const unsigned char *y; |
| unsigned char *p; |
| unsigned int i; |
| int offset_to_next_row; |
| |
| p = priv->plane[0]; |
| y = priv->Y; |
| offset_to_next_row = priv->bytes_per_row[0]; |
| |
| for (i = sy; i > 0; i--) { |
| memcpy(p, y, sx); |
| y += 8; |
| p += offset_to_next_row; |
| } |
| } |
| |
| /** |
| * YCrCb -> Grey (2x1, 2x2) |
| * .-------. |
| * | 1 | 2 | |
| * `-------' |
| */ |
| static void YCrCB_to_Grey_2xN(struct jdec_private *priv, int sx, int sy) |
| { |
| const unsigned char *y; |
| unsigned char *p; |
| unsigned int i; |
| int offset_to_next_row; |
| |
| p = priv->plane[0]; |
| y = priv->Y; |
| offset_to_next_row = priv->bytes_per_row[0]; |
| |
| for (i = sy; i > 0; i--) { |
| memcpy(p, y, sx); |
| y += 16; |
| p += offset_to_next_row; |
| } |
| } |
| |
| static int initialize_grey(struct jdec_private *priv, |
| unsigned int *bytes_per_blocklines, |
| unsigned int *bytes_per_mcu) |
| { |
| if (!priv->bytes_per_row[0]) |
| priv->bytes_per_row[0] = priv->width; |
| if (!priv->components[0]) |
| priv->components[0] = malloc(priv->height * priv->bytes_per_row[0]); |
| |
| bytes_per_blocklines[0] = priv->bytes_per_row[0] << 3; |
| bytes_per_mcu[0] = 8; |
| |
| return !priv->components[0]; |
| } |
| |
| static const struct tinyjpeg_colorspace format_grey = |
| { |
| { |
| YCrCB_to_Grey_1xN, |
| YCrCB_to_Grey_1xN, |
| YCrCB_to_Grey_2xN, |
| YCrCB_to_Grey_2xN, |
| }, |
| tinyjpeg_decode_mcu_1comp_table, |
| initialize_grey |
| }; |
| |
| const tinyjpeg_colorspace_t TINYJPEG_FMT_GREY = &format_grey; |