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