139 lines
3.9 KiB
C
139 lines
3.9 KiB
C
/*
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* Small jpeg decoder library
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*
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* Copyright (c) 2006, Luc Saillard <luc@saillard.org>
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* All rights reserved.
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions are met:
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*
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* - Redistributions of source code must retain the above copyright notice,
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* this list of conditions and the following disclaimer.
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*
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* - Redistributions in binary form must reproduce the above copyright notice,
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* this list of conditions and the following disclaimer in the documentation
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* and/or other materials provided with the distribution.
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*
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* - Neither the name of the author nor the names of its contributors may be
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* used to endorse or promote products derived from this software without
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* specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
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* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
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* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
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* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
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* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
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* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
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* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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* POSSIBILITY OF SUCH DAMAGE.
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*
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*/
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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#include <stdint.h>
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#include "tinyjpeg.h"
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#include "tinyjpeg-internal.h"
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/*
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* Decode a 1x1 directly in 1 color
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*/
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static void decode_MCU_1x1_1plane(struct jdec_private *priv)
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{
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// Y
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tinyjpeg_process_Huffman_data_unit(priv, cY);
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IDCT(&priv->component_infos[cY], priv->Y, 8);
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// Cb
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tinyjpeg_process_Huffman_data_unit(priv, cCb);
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IDCT(&priv->component_infos[cCb], priv->Cb, 8);
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// Cr
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tinyjpeg_process_Huffman_data_unit(priv, cCr);
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IDCT(&priv->component_infos[cCr], priv->Cr, 8);
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}
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/*
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* Decode a 2x1
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* .-------.
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* | 1 | 2 |
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* `-------'
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*/
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static void decode_MCU_2x1_1plane(struct jdec_private *priv)
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{
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// Y
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tinyjpeg_process_Huffman_data_unit(priv, cY);
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IDCT(&priv->component_infos[cY], priv->Y, 16);
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tinyjpeg_process_Huffman_data_unit(priv, cY);
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IDCT(&priv->component_infos[cY], priv->Y+8, 16);
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// Cb
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tinyjpeg_process_Huffman_data_unit(priv, cCb);
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// Cr
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tinyjpeg_process_Huffman_data_unit(priv, cCr);
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}
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/*
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* Decode a 2x2 directly in GREY format (8bits)
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* .-------.
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* | 1 | 2 |
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* |---+---|
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* | 3 | 4 |
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* `-------'
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*/
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static void decode_MCU_2x2_1plane(struct jdec_private *priv)
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{
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// Y
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tinyjpeg_process_Huffman_data_unit(priv, cY);
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IDCT(&priv->component_infos[cY], priv->Y, 16);
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tinyjpeg_process_Huffman_data_unit(priv, cY);
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IDCT(&priv->component_infos[cY], priv->Y+8, 16);
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tinyjpeg_process_Huffman_data_unit(priv, cY);
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IDCT(&priv->component_infos[cY], priv->Y+64*2, 16);
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tinyjpeg_process_Huffman_data_unit(priv, cY);
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IDCT(&priv->component_infos[cY], priv->Y+64*2+8, 16);
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// Cb
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tinyjpeg_process_Huffman_data_unit(priv, cCb);
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// Cr
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tinyjpeg_process_Huffman_data_unit(priv, cCr);
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}
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/*
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* Decode a 1x2 mcu
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* .---.
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* | 1 |
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* |---|
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* | 2 |
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* `---'
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*/
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static void decode_MCU_1x2_1plane(struct jdec_private *priv)
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{
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// Y
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tinyjpeg_process_Huffman_data_unit(priv, cY);
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IDCT(&priv->component_infos[cY], priv->Y, 8);
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tinyjpeg_process_Huffman_data_unit(priv, cY);
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IDCT(&priv->component_infos[cY], priv->Y+64, 8);
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// Cb
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tinyjpeg_process_Huffman_data_unit(priv, cCb);
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// Cr
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tinyjpeg_process_Huffman_data_unit(priv, cCr);
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}
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const decode_MCU_fct tinyjpeg_decode_mcu_1comp_table[4] = {
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decode_MCU_1x1_1plane,
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decode_MCU_1x2_1plane,
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decode_MCU_2x1_1plane,
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decode_MCU_2x2_1plane,
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};
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