192 lines
5.4 KiB
C
192 lines
5.4 KiB
C
/* ****************************************************************************
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* file/decode/std/picture.c -- decode a picture file.
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* Copyright (C) 2017 Thomas "Cakeisalie5" Touhey <thomas@touhey.fr>
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*
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* This file is part of libcasio.
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* libcasio is free software; you can redistribute it and/or modify it
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* under the terms of the GNU Lesser General Public License as published by
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* the Free Software Foundation; either version 3.0 of the License,
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* or (at your option) any later version.
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*
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* libcasio is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
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* See the GNU Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public License
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* along with libcasio; if not, see <http://www.gnu.org/licenses/>.
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* ************************************************************************* */
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#include "../decode.h"
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#include <zlib.h>
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/* ---
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* Obfuscation-related functions.
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* --- */
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/**
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* g3p_deobfuscate:
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* De-obfuscate the image data.
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*
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* @arg buf the buffer.
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* @arg n the buffer size.
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*/
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CASIO_LOCAL void g3p_deobfuscate(unsigned char *buf, size_t n)
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{
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while (n--) {
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unsigned char byte = ~*buf;
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*buf++ = (byte << 5) | (byte >> 3);
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}
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}
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/* ---
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* Prizm Picture decoding function.
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* --- */
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/**
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* casio_decode_std_g3p:
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* Decode a G3P file.
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*
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* @arg handle the handle.
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* @arg buffer the buffer to read from.
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* @arg std the standard header.
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* @arg pic the standard picture header.
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* @return the error code (0 if ok).
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*/
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int CASIO_EXPORT casio_decode_std_g3p(casio_file_t **h, casio_stream_t *buffer,
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casio_standard_header_t *std, casio_standard_picheader_t *pic)
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{
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int err = casio_error_alloc, z_err;
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casio_prizm_picture_subheader_t ihd;
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unsigned int width, height; casio_uint16_t gen;
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casio_uint16_t rawcol; const char *coldesc; size_t rawsize;
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uLong inflated_size, adl;
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size_t deflated_size; casio_uint32_t checksum;
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casio_pictureformat_t picfmt;
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casio_uint8_t *defbuf = NULL, *infbuf = NULL;
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casio_file_t *handle;
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*h = NULL;
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(void)pic;
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/* Read the image header. */
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DREAD(ihd)
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width = be16toh(ihd.casio_prizm_picture_subheader_width);
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height = be16toh(ihd.casio_prizm_picture_subheader_height);
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msg((ll_info, "Width: %upx, height: %upx", width, height));
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rawcol = be16toh(ihd.casio_prizm_picture_subheader_color_depth);
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switch (rawcol) {
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case g3p_color_4bit: picfmt = casio_pictureformat_4bit_code;
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coldesc = "4-bit"; break;
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case g3p_color_16bit: picfmt = casio_pictureformat_16bit;
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coldesc = "16-bit"; break;
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default:
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msg((ll_error, "Unknown picture format: 0x%04" CASIO_PRIX16,
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rawcol));
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err = casio_error_magic; goto fail;
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}
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msg((ll_info, "Picture format: %s", coldesc));
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gen = be16toh(ihd.casio_prizm_picture_subheader_generator_id);
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msg((ll_info, "Generator ID: 0x%04X", gen));
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msg((ll_info, "-"));
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/* Read the deflated image. */
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deflated_size = be32toh(ihd.casio_prizm_picture_subheader_data_size)
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- 6; /* FIXME: dangerous */
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msg((ll_info, "Reading %" CASIO_PRIuSIZE "B of deflated data",
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deflated_size));
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err = casio_error_alloc;
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if (!(defbuf = casio_alloc(deflated_size, 1)))
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goto fail;
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READ(defbuf, deflated_size)
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/* Unobfuscate if required. */
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if (std->casio_standard_header_obfuscated0) {
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msg((ll_info, "Is obfuscated, let's deobfuscate!"));
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g3p_deobfuscate(defbuf, deflated_size);
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}
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/* Make the destination buffer. */
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rawsize = casio_get_picture_size(NULL, picfmt, width, height);
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err = casio_error_alloc;
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if (!(infbuf = casio_alloc(rawsize, 1)))
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goto fail;
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/* uncompress */
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inflated_size = (uLong)rawsize;
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z_err = uncompress(infbuf, &inflated_size, defbuf, (uLong)deflated_size);
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if (z_err) {
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msg((ll_fatal, "Zlib error %d: %s", z_err, zError(err)));
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err = casio_error_magic;
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goto fail;
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}
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casio_free(defbuf); defbuf = NULL;
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/* check the checksum */
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READ(&checksum, sizeof(casio_uint32_t))
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if (std->casio_standard_header_obfuscated0)
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g3p_deobfuscate((void*)&checksum, sizeof(casio_uint32_t));
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checksum = be32toh(checksum);
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adl = adler32(0, infbuf, inflated_size);
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if (adl != (uLong)checksum) {
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msg((ll_fatal, "Incorrect Adler32 checksum!"));
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msg((ll_fatal, "Expected 0x%08" CASIO_PRIX32 ", got 0x%08lX",
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checksum, adl));
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err = casio_error_csum;
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goto fail;
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}
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/* make the handle */
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err = casio_make_picture(h, ihd.casio_prizm_picture_subheader_width,
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ihd.casio_prizm_picture_subheader_height);
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if (err) goto fail;
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handle = *h;
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/* then store it */
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casio_decode_picture(handle->casio_file_pixels, infbuf,
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picfmt, handle->casio_file_width, handle->casio_file_height);
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casio_free(infbuf); infbuf = NULL;
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/* TODO: footers? */
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/* no error */
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return (0);
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fail:
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casio_free_file(*h); *h = NULL;
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casio_free(infbuf); casio_free(defbuf);
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return (err);
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}
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/* ---
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* Classpad Picture decoding function.
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* --- */
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/**
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* casio_decode_std_c2p:
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* Decode Classpad images.
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*
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* @arg handle the handle.
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* @arg buffer the buffer to read from.
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* @arg std the standard header.
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* @arg pic the standard picture header.
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* @return the error code (0 if ok).
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*/
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int CASIO_EXPORT casio_decode_std_c2p(casio_file_t **h, casio_stream_t *buffer,
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casio_standard_header_t *std, casio_standard_picheader_t *pic)
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{
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(void)h; (void)buffer;
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(void)std; (void)pic;
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/* TODO */
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msg((ll_info, "C2P files are not managed yet."));
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/* no error */
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return (casio_error_magic);
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}
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