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1 /*
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2 * jcinit.c
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3 *
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4 * Copyright (C) 1991-1997, Thomas G. Lane.
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5 * This file is part of the Independent JPEG Group's software.
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6 * For conditions of distribution and use, see the accompanying README file.
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7 *
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8 * This file contains initialization logic for the JPEG compressor.
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9 * This routine is in charge of selecting the modules to be executed and
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10 * making an initialization call to each one.
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11 *
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12 * Logically, this code belongs in jcmaster.c. It's split out because
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13 * linking this routine implies linking the entire compression library.
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14 * For a transcoding-only application, we want to be able to use jcmaster.c
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15 * without linking in the whole library.
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16 */
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17
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18 #define JPEG_INTERNALS
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19 #include "jinclude.h"
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20 #include "jpeglib.h"
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21
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22
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23 /*
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24 * Master selection of compression modules.
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25 * This is done once at the start of processing an image. We determine
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26 * which modules will be used and give them appropriate initialization calls.
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27 */
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28
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29 GLOBAL(void)
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30 jinit_compress_master (j_compress_ptr cinfo)
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31 {
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32 /* Initialize master control (includes parameter checking/processing) */
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33 jinit_c_master_control(cinfo, FALSE /* full compression */);
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34
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35 /* Preprocessing */
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36 if (! cinfo->raw_data_in) {
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37 jinit_color_converter(cinfo);
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38 jinit_downsampler(cinfo);
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39 jinit_c_prep_controller(cinfo, FALSE /* never need full buffer here */);
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40 }
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41 /* Forward DCT */
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42 jinit_forward_dct(cinfo);
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43 /* Entropy encoding: either Huffman or arithmetic coding. */
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44 if (cinfo->arith_code) {
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45 ERREXIT(cinfo, JERR_ARITH_NOTIMPL);
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46 } else {
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47 if (cinfo->progressive_mode) {
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48 #ifdef C_PROGRESSIVE_SUPPORTED
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49 jinit_phuff_encoder(cinfo);
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50 #else
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51 ERREXIT(cinfo, JERR_NOT_COMPILED);
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52 #endif
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53 } else
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54 jinit_huff_encoder(cinfo);
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55 }
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56
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57 /* Need a full-image coefficient buffer in any multi-pass mode. */
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58 jinit_c_coef_controller(cinfo,
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59 (boolean) (cinfo->num_scans > 1 || cinfo->optimize_coding));
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60 jinit_c_main_controller(cinfo, FALSE /* never need full buffer here */);
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61
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62 jinit_marker_writer(cinfo);
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63
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64 /* We can now tell the memory manager to allocate virtual arrays. */
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65 (*cinfo->mem->realize_virt_arrays) ((j_common_ptr) cinfo);
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66
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67 /* Write the datastream header (SOI) immediately.
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68 * Frame and scan headers are postponed till later.
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69 * This lets application insert special markers after the SOI.
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70 */
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71 (*cinfo->marker->write_file_header) (cinfo);
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72 }
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