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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 } |