#if !defined(_FX_JPEG_TURBO_) | |
/* | |
* jcapistd.c | |
* | |
* Copyright (C) 1994-1996, Thomas G. Lane. | |
* This file is part of the Independent JPEG Group's software. | |
* For conditions of distribution and use, see the accompanying README file. | |
* | |
* This file contains application interface code for the compression half | |
* of the JPEG library. These are the "standard" API routines that are | |
* used in the normal full-compression case. They are not used by a | |
* transcoding-only application. Note that if an application links in | |
* jpeg_start_compress, it will end up linking in the entire compressor. | |
* We thus must separate this file from jcapimin.c to avoid linking the | |
* whole compression library into a transcoder. | |
*/ | |
#define JPEG_INTERNALS | |
#include "jinclude.h" | |
#include "jpeglib.h" | |
/* | |
* Compression initialization. | |
* Before calling this, all parameters and a data destination must be set up. | |
* | |
* We require a write_all_tables parameter as a failsafe check when writing | |
* multiple datastreams from the same compression object. Since prior runs | |
* will have left all the tables marked sent_table=TRUE, a subsequent run | |
* would emit an abbreviated stream (no tables) by default. This may be what | |
* is wanted, but for safety's sake it should not be the default behavior: | |
* programmers should have to make a deliberate choice to emit abbreviated | |
* images. Therefore the documentation and examples should encourage people | |
* to pass write_all_tables=TRUE; then it will take active thought to do the | |
* wrong thing. | |
*/ | |
GLOBAL(void) | |
jpeg_start_compress (j_compress_ptr cinfo, boolean write_all_tables) | |
{ | |
if (cinfo->global_state != CSTATE_START) | |
ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state); | |
if (write_all_tables) | |
jpeg_suppress_tables(cinfo, FALSE); /* mark all tables to be written */ | |
/* (Re)initialize error mgr and destination modules */ | |
(*cinfo->err->reset_error_mgr) ((j_common_ptr) cinfo); | |
(*cinfo->dest->init_destination) (cinfo); | |
/* Perform master selection of active modules */ | |
jinit_compress_master(cinfo); | |
/* Set up for the first pass */ | |
(*cinfo->master->prepare_for_pass) (cinfo); | |
/* Ready for application to drive first pass through jpeg_write_scanlines | |
* or jpeg_write_raw_data. | |
*/ | |
cinfo->next_scanline = 0; | |
cinfo->global_state = (cinfo->raw_data_in ? CSTATE_RAW_OK : CSTATE_SCANNING); | |
} | |
/* | |
* Write some scanlines of data to the JPEG compressor. | |
* | |
* The return value will be the number of lines actually written. | |
* This should be less than the supplied num_lines only in case that | |
* the data destination module has requested suspension of the compressor, | |
* or if more than image_height scanlines are passed in. | |
* | |
* Note: we warn about excess calls to jpeg_write_scanlines() since | |
* this likely signals an application programmer error. However, | |
* excess scanlines passed in the last valid call are *silently* ignored, | |
* so that the application need not adjust num_lines for end-of-image | |
* when using a multiple-scanline buffer. | |
*/ | |
GLOBAL(JDIMENSION) | |
jpeg_write_scanlines (j_compress_ptr cinfo, JSAMPARRAY scanlines, | |
JDIMENSION num_lines) | |
{ | |
JDIMENSION row_ctr, rows_left; | |
if (cinfo->global_state != CSTATE_SCANNING) | |
ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state); | |
if (cinfo->next_scanline >= cinfo->image_height) | |
WARNMS(cinfo, JWRN_TOO_MUCH_DATA); | |
/* Call progress monitor hook if present */ | |
if (cinfo->progress != NULL) { | |
cinfo->progress->pass_counter = (long) cinfo->next_scanline; | |
cinfo->progress->pass_limit = (long) cinfo->image_height; | |
(*cinfo->progress->progress_monitor) ((j_common_ptr) cinfo); | |
} | |
/* Give master control module another chance if this is first call to | |
* jpeg_write_scanlines. This lets output of the frame/scan headers be | |
* delayed so that application can write COM, etc, markers between | |
* jpeg_start_compress and jpeg_write_scanlines. | |
*/ | |
if (cinfo->master->call_pass_startup) | |
(*cinfo->master->pass_startup) (cinfo); | |
/* Ignore any extra scanlines at bottom of image. */ | |
rows_left = cinfo->image_height - cinfo->next_scanline; | |
if (num_lines > rows_left) | |
num_lines = rows_left; | |
row_ctr = 0; | |
(*cinfo->main->process_data) (cinfo, scanlines, &row_ctr, num_lines); | |
cinfo->next_scanline += row_ctr; | |
return row_ctr; | |
} | |
/* | |
* Alternate entry point to write raw data. | |
* Processes exactly one iMCU row per call, unless suspended. | |
*/ | |
GLOBAL(JDIMENSION) | |
jpeg_write_raw_data (j_compress_ptr cinfo, JSAMPIMAGE data, | |
JDIMENSION num_lines) | |
{ | |
JDIMENSION lines_per_iMCU_row; | |
if (cinfo->global_state != CSTATE_RAW_OK) | |
ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state); | |
if (cinfo->next_scanline >= cinfo->image_height) { | |
WARNMS(cinfo, JWRN_TOO_MUCH_DATA); | |
return 0; | |
} | |
/* Call progress monitor hook if present */ | |
if (cinfo->progress != NULL) { | |
cinfo->progress->pass_counter = (long) cinfo->next_scanline; | |
cinfo->progress->pass_limit = (long) cinfo->image_height; | |
(*cinfo->progress->progress_monitor) ((j_common_ptr) cinfo); | |
} | |
/* Give master control module another chance if this is first call to | |
* jpeg_write_raw_data. This lets output of the frame/scan headers be | |
* delayed so that application can write COM, etc, markers between | |
* jpeg_start_compress and jpeg_write_raw_data. | |
*/ | |
if (cinfo->master->call_pass_startup) | |
(*cinfo->master->pass_startup) (cinfo); | |
/* Verify that at least one iMCU row has been passed. */ | |
lines_per_iMCU_row = cinfo->max_v_samp_factor * DCTSIZE; | |
if (num_lines < lines_per_iMCU_row) | |
ERREXIT(cinfo, JERR_BUFFER_SIZE); | |
/* Directly compress the row. */ | |
if (! (*cinfo->coef->compress_data) (cinfo, data)) { | |
/* If compressor did not consume the whole row, suspend processing. */ | |
return 0; | |
} | |
/* OK, we processed one iMCU row. */ | |
cinfo->next_scanline += lines_per_iMCU_row; | |
return lines_per_iMCU_row; | |
} | |
#endif //_FX_JPEG_TURBO_ |