diff options
Diffstat (limited to 'src/jpeg-8c/jcmainct.c')
| -rw-r--r-- | src/jpeg-8c/jcmainct.c | 293 |
1 files changed, 293 insertions, 0 deletions
diff --git a/src/jpeg-8c/jcmainct.c b/src/jpeg-8c/jcmainct.c new file mode 100644 index 00000000..b9f525b2 --- /dev/null +++ b/src/jpeg-8c/jcmainct.c @@ -0,0 +1,293 @@ +/* + * jcmainct.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 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" + + +/* Note: currently, there is no operating mode in which a full-image buffer + * is needed at this step. If there were, that mode could not be used with + * "raw data" input, since this module is bypassed in that case. However, + * we've left the code here for possible use in special applications. + */ +#undef FULL_MAIN_BUFFER_SUPPORTED + + +/* 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]; + +#ifdef FULL_MAIN_BUFFER_SUPPORTED + /* If using full-image storage, this array holds pointers to virtual-array + * control blocks for each component. Unused if not full-image storage. + */ + jvirt_sarray_ptr whole_image[MAX_COMPONENTS]; +#endif +} my_main_controller; + +typedef my_main_controller * my_main_ptr; + + +/* Forward declarations */ +METHODDEF(void) process_data_simple_main + JPP((j_compress_ptr cinfo, JSAMPARRAY input_buf, + JDIMENSION *in_row_ctr, JDIMENSION in_rows_avail)); +#ifdef FULL_MAIN_BUFFER_SUPPORTED +METHODDEF(void) process_data_buffer_main + JPP((j_compress_ptr cinfo, JSAMPARRAY input_buf, + JDIMENSION *in_row_ctr, JDIMENSION in_rows_avail)); +#endif + + +/* + * 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; + + 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 */ + + switch (pass_mode) { + case JBUF_PASS_THRU: +#ifdef FULL_MAIN_BUFFER_SUPPORTED + if (main_ptr->whole_image[0] != NULL) + ERREXIT(cinfo, JERR_BAD_BUFFER_MODE); +#endif + main_ptr->pub.process_data = process_data_simple_main; + break; +#ifdef FULL_MAIN_BUFFER_SUPPORTED + case JBUF_SAVE_SOURCE: + case JBUF_CRANK_DEST: + case JBUF_SAVE_AND_PASS: + if (main_ptr->whole_image[0] == NULL) + ERREXIT(cinfo, JERR_BAD_BUFFER_MODE); + main_ptr->pub.process_data = process_data_buffer_main; + break; +#endif + default: + ERREXIT(cinfo, JERR_BAD_BUFFER_MODE); + break; + } +} + + +/* + * 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 < (JDIMENSION) cinfo->min_DCT_v_scaled_size) + (*cinfo->prep->pre_process_data) (cinfo, + input_buf, in_row_ctr, in_rows_avail, + main_ptr->buffer, &main_ptr->rowgroup_ctr, + (JDIMENSION) cinfo->min_DCT_v_scaled_size); + + /* 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 != (JDIMENSION) cinfo->min_DCT_v_scaled_size) + 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++; + } +} + + +#ifdef FULL_MAIN_BUFFER_SUPPORTED + +/* + * Process some data. + * This routine handles all of the modes that use a full-size buffer. + */ + +METHODDEF(void) +process_data_buffer_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; + int ci; + jpeg_component_info *compptr; + boolean writing = (main_ptr->pass_mode != JBUF_CRANK_DEST); + + while (main_ptr->cur_iMCU_row < cinfo->total_iMCU_rows) { + /* Realign the virtual buffers if at the start of an iMCU row. */ + if (main_ptr->rowgroup_ctr == 0) { + for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components; + ci++, compptr++) { + main_ptr->buffer[ci] = (*cinfo->mem->access_virt_sarray) + ((j_common_ptr) cinfo, main_ptr->whole_image[ci], + main_ptr->cur_iMCU_row * (compptr->v_samp_factor * DCTSIZE), + (JDIMENSION) (compptr->v_samp_factor * DCTSIZE), writing); + } + /* In a read pass, pretend we just read some source data. */ + if (! writing) { + *in_row_ctr += cinfo->max_v_samp_factor * DCTSIZE; + main_ptr->rowgroup_ctr = DCTSIZE; + } + } + + /* If a write pass, read input data until the current iMCU row is full. */ + /* Note: preprocessor will pad if necessary to fill the last iMCU row. */ + if (writing) { + (*cinfo->prep->pre_process_data) (cinfo, + input_buf, in_row_ctr, in_rows_avail, + main_ptr->buffer, &main_ptr->rowgroup_ctr, + (JDIMENSION) DCTSIZE); + /* Return to application if we need more data to fill the iMCU row. */ + if (main_ptr->rowgroup_ctr < DCTSIZE) + return; + } + + /* Emit data, unless this is a sink-only pass. */ + if (main_ptr->pass_mode != JBUF_SAVE_SOURCE) { + 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; + } + } + + /* If get here, we are done with this iMCU row. Mark buffer empty. */ + main_ptr->rowgroup_ctr = 0; + main_ptr->cur_iMCU_row++; + } +} + +#endif /* FULL_MAIN_BUFFER_SUPPORTED */ + + +/* + * 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) { +#ifdef FULL_MAIN_BUFFER_SUPPORTED + /* Allocate a full-image virtual array for each component */ + /* Note we pad the bottom to a multiple of the iMCU height */ + for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components; + ci++, compptr++) { + main_ptr->whole_image[ci] = (*cinfo->mem->request_virt_sarray) + ((j_common_ptr) cinfo, JPOOL_IMAGE, FALSE, + compptr->width_in_blocks * compptr->DCT_h_scaled_size, + (JDIMENSION) jround_up((long) compptr->height_in_blocks, + (long) compptr->v_samp_factor) * DCTSIZE, + (JDIMENSION) (compptr->v_samp_factor * compptr->DCT_v_scaled_size)); + } +#else + ERREXIT(cinfo, JERR_BAD_BUFFER_MODE); +#endif + } else { +#ifdef FULL_MAIN_BUFFER_SUPPORTED + main_ptr->whole_image[0] = NULL; /* flag for no virtual arrays */ +#endif + /* 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 * compptr->DCT_h_scaled_size, + (JDIMENSION) (compptr->v_samp_factor * compptr->DCT_v_scaled_size)); + } + } +} |