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Diffstat (limited to 'media/libjpeg/jcmainct.c')
| -rw-r--r-- | media/libjpeg/jcmainct.c | 162 |
1 files changed, 162 insertions, 0 deletions
diff --git a/media/libjpeg/jcmainct.c b/media/libjpeg/jcmainct.c new file mode 100644 index 000000000..d01f46364 --- /dev/null +++ b/media/libjpeg/jcmainct.c @@ -0,0 +1,162 @@ +/* + * jcmainct.c + * + * This file was part of the Independent JPEG Group's software: + * Copyright (C) 1994-1996, Thomas G. Lane. + * It was modified by The libjpeg-turbo Project to include only code relevant + * to libjpeg-turbo. + * For conditions of distribution and use, see the accompanying README.ijg + * file. + * + * This file contains the main buffer controller for compression. + * The main buffer lies between the pre-processor and the JPEG + * compressor proper; it holds downsampled data in the JPEG colorspace. + */ + +#define JPEG_INTERNALS +#include "jinclude.h" +#include "jpeglib.h" + + +/* Private buffer controller object */ + +typedef struct { + struct jpeg_c_main_controller pub; /* public fields */ + + JDIMENSION cur_iMCU_row; /* number of current iMCU row */ + JDIMENSION rowgroup_ctr; /* counts row groups received in iMCU row */ + boolean suspended; /* remember if we suspended output */ + J_BUF_MODE pass_mode; /* current operating mode */ + + /* If using just a strip buffer, this points to the entire set of buffers + * (we allocate one for each component). In the full-image case, this + * points to the currently accessible strips of the virtual arrays. + */ + JSAMPARRAY buffer[MAX_COMPONENTS]; +} my_main_controller; + +typedef my_main_controller *my_main_ptr; + + +/* Forward declarations */ +METHODDEF(void) process_data_simple_main + (j_compress_ptr cinfo, JSAMPARRAY input_buf, JDIMENSION *in_row_ctr, + JDIMENSION in_rows_avail); + + +/* + * Initialize for a processing pass. + */ + +METHODDEF(void) +start_pass_main (j_compress_ptr cinfo, J_BUF_MODE pass_mode) +{ + my_main_ptr main_ptr = (my_main_ptr) cinfo->main; + + /* Do nothing in raw-data mode. */ + if (cinfo->raw_data_in) + return; + + if (pass_mode != JBUF_PASS_THRU) + ERREXIT(cinfo, JERR_BAD_BUFFER_MODE); + + main_ptr->cur_iMCU_row = 0; /* initialize counters */ + main_ptr->rowgroup_ctr = 0; + main_ptr->suspended = FALSE; + main_ptr->pass_mode = pass_mode; /* save mode for use by process_data */ + main_ptr->pub.process_data = process_data_simple_main; +} + + +/* + * Process some data. + * This routine handles the simple pass-through mode, + * where we have only a strip buffer. + */ + +METHODDEF(void) +process_data_simple_main (j_compress_ptr cinfo, + JSAMPARRAY input_buf, JDIMENSION *in_row_ctr, + JDIMENSION in_rows_avail) +{ + my_main_ptr main_ptr = (my_main_ptr) cinfo->main; + + while (main_ptr->cur_iMCU_row < cinfo->total_iMCU_rows) { + /* Read input data if we haven't filled the main buffer yet */ + if (main_ptr->rowgroup_ctr < DCTSIZE) + (*cinfo->prep->pre_process_data) (cinfo, + input_buf, in_row_ctr, in_rows_avail, + main_ptr->buffer, &main_ptr->rowgroup_ctr, + (JDIMENSION) DCTSIZE); + + /* If we don't have a full iMCU row buffered, return to application for + * more data. Note that preprocessor will always pad to fill the iMCU row + * at the bottom of the image. + */ + if (main_ptr->rowgroup_ctr != DCTSIZE) + return; + + /* Send the completed row to the compressor */ + if (! (*cinfo->coef->compress_data) (cinfo, main_ptr->buffer)) { + /* If compressor did not consume the whole row, then we must need to + * suspend processing and return to the application. In this situation + * we pretend we didn't yet consume the last input row; otherwise, if + * it happened to be the last row of the image, the application would + * think we were done. + */ + if (! main_ptr->suspended) { + (*in_row_ctr)--; + main_ptr->suspended = TRUE; + } + return; + } + /* We did finish the row. Undo our little suspension hack if a previous + * call suspended; then mark the main buffer empty. + */ + if (main_ptr->suspended) { + (*in_row_ctr)++; + main_ptr->suspended = FALSE; + } + main_ptr->rowgroup_ctr = 0; + main_ptr->cur_iMCU_row++; + } +} + + +/* + * Initialize main buffer controller. + */ + +GLOBAL(void) +jinit_c_main_controller (j_compress_ptr cinfo, boolean need_full_buffer) +{ + my_main_ptr main_ptr; + int ci; + jpeg_component_info *compptr; + + main_ptr = (my_main_ptr) + (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE, + sizeof(my_main_controller)); + cinfo->main = (struct jpeg_c_main_controller *) main_ptr; + main_ptr->pub.start_pass = start_pass_main; + + /* We don't need to create a buffer in raw-data mode. */ + if (cinfo->raw_data_in) + return; + + /* Create the buffer. It holds downsampled data, so each component + * may be of a different size. + */ + if (need_full_buffer) { + ERREXIT(cinfo, JERR_BAD_BUFFER_MODE); + } else { + /* Allocate a strip buffer for each component */ + for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components; + ci++, compptr++) { + main_ptr->buffer[ci] = (*cinfo->mem->alloc_sarray) + ((j_common_ptr) cinfo, JPOOL_IMAGE, + compptr->width_in_blocks * DCTSIZE, + (JDIMENSION) (compptr->v_samp_factor * DCTSIZE)); + } + } +} |