/*
* 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"
/*
* Decode a 1x1 directly in 1 color
*/
static void decode_MCU_1x1_1plane(struct jdec_private *priv)
{
// Y
tinyjpeg_process_Huffman_data_unit(priv, cY);
IDCT(&priv->component_infos[cY], priv->Y, 8);
// Cb
tinyjpeg_process_Huffman_data_unit(priv, cCb);
IDCT(&priv->component_infos[cCb], priv->Cb, 8);
// Cr
tinyjpeg_process_Huffman_data_unit(priv, cCr);
IDCT(&priv->component_infos[cCr], priv->Cr, 8);
}
/*
* Decode a 2x1
* .-------.
* | 1 | 2 |
* `-------'
*/
static void decode_MCU_2x1_1plane(struct jdec_private *priv)
{
// Y
tinyjpeg_process_Huffman_data_unit(priv, cY);
IDCT(&priv->component_infos[cY], priv->Y, 16);
tinyjpeg_process_Huffman_data_unit(priv, cY);
IDCT(&priv->component_infos[cY], priv->Y+8, 16);
// Cb
tinyjpeg_process_Huffman_data_unit(priv, cCb);
// Cr
tinyjpeg_process_Huffman_data_unit(priv, cCr);
}
/*
* Decode a 2x2 directly in GREY format (8bits)
* .-------.
* | 1 | 2 |
* |---+---|
* | 3 | 4 |
* `-------'
*/
static void decode_MCU_2x2_1plane(struct jdec_private *priv)
{
// Y
tinyjpeg_process_Huffman_data_unit(priv, cY);
IDCT(&priv->component_infos[cY], priv->Y, 16);
tinyjpeg_process_Huffman_data_unit(priv, cY);
IDCT(&priv->component_infos[cY], priv->Y+8, 16);
tinyjpeg_process_Huffman_data_unit(priv, cY);
IDCT(&priv->component_infos[cY], priv->Y+64*2, 16);
tinyjpeg_process_Huffman_data_unit(priv, cY);
IDCT(&priv->component_infos[cY], priv->Y+64*2+8, 16);
// Cb
tinyjpeg_process_Huffman_data_unit(priv, cCb);
// Cr
tinyjpeg_process_Huffman_data_unit(priv, cCr);
}
/*
* Decode a 1x2 mcu
* .---.
* | 1 |
* |---|
* | 2 |
* `---'
*/
static void decode_MCU_1x2_1plane(struct jdec_private *priv)
{
// Y
tinyjpeg_process_Huffman_data_unit(priv, cY);
IDCT(&priv->component_infos[cY], priv->Y, 8);
tinyjpeg_process_Huffman_data_unit(priv, cY);
IDCT(&priv->component_infos[cY], priv->Y+64, 8);
// Cb
tinyjpeg_process_Huffman_data_unit(priv, cCb);
// Cr
tinyjpeg_process_Huffman_data_unit(priv, cCr);
}
const decode_MCU_fct tinyjpeg_decode_mcu_1comp_table[4] = {
decode_MCU_1x1_1plane,
decode_MCU_1x2_1plane,
decode_MCU_2x1_1plane,
decode_MCU_2x2_1plane,
};