diff options
Diffstat (limited to 'media/libjpeg/jcapistd.c')
| -rw-r--r-- | media/libjpeg/jcapistd.c | 162 |
1 files changed, 162 insertions, 0 deletions
diff --git a/media/libjpeg/jcapistd.c b/media/libjpeg/jcapistd.c new file mode 100644 index 0000000000..aa2aad9f66 --- /dev/null +++ b/media/libjpeg/jcapistd.c @@ -0,0 +1,162 @@ +/* + * 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.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" + + +/* + * 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; +} |