| /* |
| * jcapistd.c |
| * |
| * This file was part of the Independent JPEG Group's software: |
| * Copyright (C) 1994-1996, Thomas G. Lane. |
| * libjpeg-turbo Modifications: |
| * Copyright (C) 2022, D. R. Commander. |
| * For conditions of distribution and use, see the accompanying README.ijg |
| * 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" |
| #include "jsamplecomp.h" |
| |
| |
| #if BITS_IN_JSAMPLE == 8 |
| |
| /* |
| * 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); |
| } |
| |
| #endif |
| |
| |
| /* |
| * 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) |
| { |
| #if BITS_IN_JSAMPLE != 16 || defined(C_LOSSLESS_SUPPORTED) |
| JDIMENSION row_ctr, rows_left; |
| |
| if (cinfo->data_precision != BITS_IN_JSAMPLE) |
| ERREXIT1(cinfo, JERR_BAD_PRECISION, cinfo->data_precision); |
| |
| 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; |
| #else |
| ERREXIT1(cinfo, JERR_BAD_PRECISION, cinfo->data_precision); |
| return 0; |
| #endif |
| } |
| |
| |
| #if BITS_IN_JSAMPLE != 16 |
| |
| /* |
| * 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->data_precision != BITS_IN_JSAMPLE) |
| ERREXIT1(cinfo, JERR_BAD_PRECISION, cinfo->data_precision); |
| |
| if (cinfo->master->lossless) |
| ERREXIT(cinfo, JERR_NOTIMPL); |
| |
| 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 /* BITS_IN_JSAMPLE != 16 */ |