| 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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