Doxygen Source Code Documentation
jdtrans.c File Reference
#include "jinclude.h"#include "jpeglib.h"Go to the source code of this file.
Defines | |
| #define | JPEG_INTERNALS |
Functions | |
| LOCAL (void) transdecode_master_selection JPP((j_decompress_ptr cinfo)) | |
| jpeg_read_coefficients (j_decompress_ptr cinfo) | |
| transdecode_master_selection (j_decompress_ptr cinfo) | |
Define Documentation
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Function Documentation
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Definition at line 45 of file jdtrans.c. References jpeg_decompress_struct::buffered_image, jpeg_decompress_struct::coef, jpeg_d_coef_controller::coef_arrays, DSTATE_BUFIMAGE, DSTATE_RDCOEFS, DSTATE_READY, DSTATE_STOPPING, ERREXIT1, jpeg_decompress_struct::inputctl, JPEG_REACHED_EOI, JPEG_REACHED_SOS, JPEG_ROW_COMPLETED, JPEG_SUSPENDED, retcode, jpeg_decompress_struct::total_iMCU_rows, and transdecode_master_selection(). Referenced by main().
00046 {
00047 if (cinfo->global_state == DSTATE_READY) {
00048 /* First call: initialize active modules */
00049 transdecode_master_selection(cinfo);
00050 cinfo->global_state = DSTATE_RDCOEFS;
00051 }
00052 if (cinfo->global_state == DSTATE_RDCOEFS) {
00053 /* Absorb whole file into the coef buffer */
00054 for (;;) {
00055 int retcode;
00056 /* Call progress monitor hook if present */
00057 if (cinfo->progress != NULL)
00058 (*cinfo->progress->progress_monitor) ((j_common_ptr) cinfo);
00059 /* Absorb some more input */
00060 retcode = (*cinfo->inputctl->consume_input) (cinfo);
00061 if (retcode == JPEG_SUSPENDED)
00062 return NULL;
00063 if (retcode == JPEG_REACHED_EOI)
00064 break;
00065 /* Advance progress counter if appropriate */
00066 if (cinfo->progress != NULL &&
00067 (retcode == JPEG_ROW_COMPLETED || retcode == JPEG_REACHED_SOS)) {
00068 if (++cinfo->progress->pass_counter >= cinfo->progress->pass_limit) {
00069 /* startup underestimated number of scans; ratchet up one scan */
00070 cinfo->progress->pass_limit += (long) cinfo->total_iMCU_rows;
00071 }
00072 }
00073 }
00074 /* Set state so that jpeg_finish_decompress does the right thing */
00075 cinfo->global_state = DSTATE_STOPPING;
00076 }
00077 /* At this point we should be in state DSTATE_STOPPING if being used
00078 * standalone, or in state DSTATE_BUFIMAGE if being invoked to get access
00079 * to the coefficients during a full buffered-image-mode decompression.
00080 */
00081 if ((cinfo->global_state == DSTATE_STOPPING ||
00082 cinfo->global_state == DSTATE_BUFIMAGE) && cinfo->buffered_image) {
00083 return cinfo->coef->coef_arrays;
00084 }
00085 /* Oops, improper usage */
00086 ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
00087 return NULL; /* keep compiler happy */
00088 }
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Definition at line 97 of file jdtrans.c. References jpeg_decompress_struct::arith_code, jpeg_decompress_struct::buffered_image, ERREXIT, jpeg_input_controller::has_multiple_scans, jpeg_decompress_struct::inputctl, JERR_ARITH_NOTIMPL, jinit_d_coef_controller(), jinit_huff_decoder(), jinit_phuff_decoder(), L, jpeg_decompress_struct::num_components, jpeg_decompress_struct::progressive_mode, and jpeg_decompress_struct::total_iMCU_rows. Referenced by jpeg_read_coefficients().
00098 {
00099 /* This is effectively a buffered-image operation. */
00100 cinfo->buffered_image = TRUE;
00101
00102 /* Entropy decoding: either Huffman or arithmetic coding. */
00103 if (cinfo->arith_code) {
00104 ERREXIT(cinfo, JERR_ARITH_NOTIMPL);
00105 } else {
00106 if (cinfo->progressive_mode) {
00107 #ifdef D_PROGRESSIVE_SUPPORTED
00108 jinit_phuff_decoder(cinfo);
00109 #else
00110 ERREXIT(cinfo, JERR_NOT_COMPILED);
00111 #endif
00112 } else
00113 jinit_huff_decoder(cinfo);
00114 }
00115
00116 /* Always get a full-image coefficient buffer. */
00117 jinit_d_coef_controller(cinfo, TRUE);
00118
00119 /* We can now tell the memory manager to allocate virtual arrays. */
00120 (*cinfo->mem->realize_virt_arrays) ((j_common_ptr) cinfo);
00121
00122 /* Initialize input side of decompressor to consume first scan. */
00123 (*cinfo->inputctl->start_input_pass) (cinfo);
00124
00125 /* Initialize progress monitoring. */
00126 if (cinfo->progress != NULL) {
00127 int nscans;
00128 /* Estimate number of scans to set pass_limit. */
00129 if (cinfo->progressive_mode) {
00130 /* Arbitrarily estimate 2 interleaved DC scans + 3 AC scans/component. */
00131 nscans = 2 + 3 * cinfo->num_components;
00132 } else if (cinfo->inputctl->has_multiple_scans) {
00133 /* For a nonprogressive multiscan file, estimate 1 scan per component. */
00134 nscans = cinfo->num_components;
00135 } else {
00136 nscans = 1;
00137 }
00138 cinfo->progress->pass_counter = 0L;
00139 cinfo->progress->pass_limit = (long) cinfo->total_iMCU_rows * nscans;
00140 cinfo->progress->completed_passes = 0;
00141 cinfo->progress->total_passes = 1;
00142 }
00143 }
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