The Independent JPEG Group's JPEG software v5
diff --git a/jcmaster.c b/jcmaster.c
index b192aae..d9b5c03 100644
--- a/jcmaster.c
+++ b/jcmaster.c
@@ -1,133 +1,387 @@
/*
* jcmaster.c
*
- * Copyright (C) 1991, 1992, Thomas G. Lane.
+ * Copyright (C) 1991-1994, 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 control for the JPEG compressor.
- * The system-dependent (user interface) code should call jpeg_compress()
- * after doing appropriate setup of the compress_info_struct parameter.
+ * This file contains master control logic for the JPEG compressor.
+ * These routines are concerned with selecting the modules to be executed
+ * and with determining the number of passes and the work to be done in each
+ * pass.
*/
+#define JPEG_INTERNALS
#include "jinclude.h"
+#include "jpeglib.h"
-METHODDEF void
-c_per_scan_method_selection (compress_info_ptr cinfo)
-/* Central point for per-scan method selection */
-{
- /* Edge expansion */
- jselexpand(cinfo);
- /* Downsampling of pixels */
- jseldownsample(cinfo);
- /* MCU extraction */
- jselcmcu(cinfo);
-}
+/* Private state */
+typedef struct {
+ struct jpeg_comp_master pub; /* public fields */
+
+ int pass_number; /* eventually need more complex state... */
+} my_comp_master;
+
+typedef my_comp_master * my_master_ptr;
+
+
+/*
+ * Support routines that do various essential calculations.
+ */
LOCAL void
-c_initial_method_selection (compress_info_ptr cinfo)
-/* Central point for initial method selection */
+initial_setup (j_compress_ptr cinfo)
+/* Do computations that are needed before master selection phase */
{
- /* Input image reading method selection is already done. */
- /* So is output file header formatting (both are done by user interface). */
-
- /* Gamma and color space conversion */
- jselccolor(cinfo);
- /* Entropy encoding: either Huffman or arithmetic coding. */
-#ifdef C_ARITH_CODING_SUPPORTED
- jselcarithmetic(cinfo);
-#else
- cinfo->arith_code = FALSE; /* force Huffman mode */
-#endif
- jselchuffman(cinfo);
- /* Pipeline control */
- jselcpipeline(cinfo);
- /* Overall control (that's me!) */
- cinfo->methods->c_per_scan_method_selection = c_per_scan_method_selection;
-}
-
-
-LOCAL void
-initial_setup (compress_info_ptr cinfo)
-/* Do computations that are needed before initial method selection */
-{
- short ci;
+ int ci;
jpeg_component_info *compptr;
+ long samplesperrow;
+ JDIMENSION jd_samplesperrow;
+
+ /* Sanity check on image dimensions */
+ if (cinfo->image_height <= 0 || cinfo->image_width <= 0
+ || cinfo->num_components <= 0 || cinfo->input_components <= 0)
+ ERREXIT(cinfo, JERR_EMPTY_IMAGE);
+
+ /* Make sure image isn't bigger than I can handle */
+ if ((long) cinfo->image_height > (long) JPEG_MAX_DIMENSION ||
+ (long) cinfo->image_width > (long) JPEG_MAX_DIMENSION)
+ ERREXIT1(cinfo, JERR_IMAGE_TOO_BIG, (unsigned int) JPEG_MAX_DIMENSION);
+
+ /* Width of an input scanline must be representable as JDIMENSION. */
+ samplesperrow = (long) cinfo->image_width * (long) cinfo->input_components;
+ jd_samplesperrow = (JDIMENSION) samplesperrow;
+ if ((long) jd_samplesperrow != samplesperrow)
+ ERREXIT(cinfo, JERR_WIDTH_OVERFLOW);
+
+ /* For now, precision must match compiled-in value... */
+ if (cinfo->data_precision != BITS_IN_JSAMPLE)
+ ERREXIT1(cinfo, JERR_BAD_PRECISION, cinfo->data_precision);
+
+ /* Check that number of components won't exceed internal array sizes */
+ if (cinfo->num_components > MAX_COMPONENTS)
+ ERREXIT2(cinfo, JERR_COMPONENT_COUNT, cinfo->num_components,
+ MAX_COMPONENTS);
/* Compute maximum sampling factors; check factor validity */
cinfo->max_h_samp_factor = 1;
cinfo->max_v_samp_factor = 1;
- for (ci = 0; ci < cinfo->num_components; ci++) {
- compptr = &cinfo->comp_info[ci];
+ for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
+ ci++, compptr++) {
if (compptr->h_samp_factor<=0 || compptr->h_samp_factor>MAX_SAMP_FACTOR ||
compptr->v_samp_factor<=0 || compptr->v_samp_factor>MAX_SAMP_FACTOR)
- ERREXIT(cinfo->emethods, "Bogus sampling factors");
+ ERREXIT(cinfo, JERR_BAD_SAMPLING);
cinfo->max_h_samp_factor = MAX(cinfo->max_h_samp_factor,
compptr->h_samp_factor);
cinfo->max_v_samp_factor = MAX(cinfo->max_v_samp_factor,
compptr->v_samp_factor);
-
}
- /* Compute logical downsampled dimensions of components */
- for (ci = 0; ci < cinfo->num_components; ci++) {
- compptr = &cinfo->comp_info[ci];
- compptr->true_comp_width = (cinfo->image_width * compptr->h_samp_factor
- + cinfo->max_h_samp_factor - 1)
- / cinfo->max_h_samp_factor;
- compptr->true_comp_height = (cinfo->image_height * compptr->v_samp_factor
- + cinfo->max_v_samp_factor - 1)
- / cinfo->max_v_samp_factor;
+ /* Compute dimensions of components */
+ for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
+ ci++, compptr++) {
+ /* For compression, we never do DCT scaling. */
+ compptr->DCT_scaled_size = DCTSIZE;
+ /* Size in DCT blocks */
+ compptr->width_in_blocks = (JDIMENSION)
+ jdiv_round_up((long) cinfo->image_width * (long) compptr->h_samp_factor,
+ (long) (cinfo->max_h_samp_factor * DCTSIZE));
+ compptr->height_in_blocks = (JDIMENSION)
+ jdiv_round_up((long) cinfo->image_height * (long) compptr->v_samp_factor,
+ (long) (cinfo->max_v_samp_factor * DCTSIZE));
+ /* Size in samples */
+ compptr->downsampled_width = (JDIMENSION)
+ jdiv_round_up((long) cinfo->image_width * (long) compptr->h_samp_factor,
+ (long) cinfo->max_h_samp_factor);
+ compptr->downsampled_height = (JDIMENSION)
+ jdiv_round_up((long) cinfo->image_height * (long) compptr->v_samp_factor,
+ (long) cinfo->max_v_samp_factor);
+ /* Mark component needed (this flag isn't actually used for compression) */
+ compptr->component_needed = TRUE;
+ }
+
+ /* Compute number of fully interleaved MCU rows (number of times that
+ * main controller will call coefficient controller).
+ */
+ cinfo->total_iMCU_rows = (JDIMENSION)
+ jdiv_round_up((long) cinfo->image_height,
+ (long) (cinfo->max_v_samp_factor*DCTSIZE));
+}
+
+
+LOCAL void
+per_scan_setup (j_compress_ptr cinfo)
+/* Do computations that are needed before processing a JPEG scan */
+/* cinfo->comps_in_scan and cinfo->cur_comp_info[] are already set */
+{
+ int ci, mcublks, tmp;
+ jpeg_component_info *compptr;
+
+ if (cinfo->comps_in_scan == 1) {
+
+ /* Noninterleaved (single-component) scan */
+ compptr = cinfo->cur_comp_info[0];
+
+ /* Overall image size in MCUs */
+ cinfo->MCUs_per_row = compptr->width_in_blocks;
+ cinfo->MCU_rows_in_scan = compptr->height_in_blocks;
+
+ /* For noninterleaved scan, always one block per MCU */
+ compptr->MCU_width = 1;
+ compptr->MCU_height = 1;
+ compptr->MCU_blocks = 1;
+ compptr->MCU_sample_width = DCTSIZE;
+ compptr->last_col_width = 1;
+ compptr->last_row_height = 1;
+
+ /* Prepare array describing MCU composition */
+ cinfo->blocks_in_MCU = 1;
+ cinfo->MCU_membership[0] = 0;
+
+ } else {
+
+ /* Interleaved (multi-component) scan */
+ if (cinfo->comps_in_scan <= 0 || cinfo->comps_in_scan > MAX_COMPS_IN_SCAN)
+ ERREXIT2(cinfo, JERR_COMPONENT_COUNT, cinfo->comps_in_scan,
+ MAX_COMPS_IN_SCAN);
+
+ /* Overall image size in MCUs */
+ cinfo->MCUs_per_row = (JDIMENSION)
+ jdiv_round_up((long) cinfo->image_width,
+ (long) (cinfo->max_h_samp_factor*DCTSIZE));
+ cinfo->MCU_rows_in_scan = (JDIMENSION)
+ jdiv_round_up((long) cinfo->image_height,
+ (long) (cinfo->max_v_samp_factor*DCTSIZE));
+
+ cinfo->blocks_in_MCU = 0;
+
+ for (ci = 0; ci < cinfo->comps_in_scan; ci++) {
+ compptr = cinfo->cur_comp_info[ci];
+ /* Sampling factors give # of blocks of component in each MCU */
+ compptr->MCU_width = compptr->h_samp_factor;
+ compptr->MCU_height = compptr->v_samp_factor;
+ compptr->MCU_blocks = compptr->MCU_width * compptr->MCU_height;
+ compptr->MCU_sample_width = compptr->MCU_width * DCTSIZE;
+ /* Figure number of non-dummy blocks in last MCU column & row */
+ tmp = (int) (compptr->width_in_blocks % compptr->MCU_width);
+ if (tmp == 0) tmp = compptr->MCU_width;
+ compptr->last_col_width = tmp;
+ tmp = (int) (compptr->height_in_blocks % compptr->MCU_height);
+ if (tmp == 0) tmp = compptr->MCU_height;
+ compptr->last_row_height = tmp;
+ /* Prepare array describing MCU composition */
+ mcublks = compptr->MCU_blocks;
+ if (cinfo->blocks_in_MCU + mcublks > MAX_BLOCKS_IN_MCU)
+ ERREXIT(cinfo, JERR_BAD_MCU_SIZE);
+ while (mcublks-- > 0) {
+ cinfo->MCU_membership[cinfo->blocks_in_MCU++] = ci;
+ }
+ }
+
+ }
+
+ /* Convert restart specified in rows to actual MCU count. */
+ /* Note that count must fit in 16 bits, so we provide limiting. */
+ if (cinfo->restart_in_rows > 0) {
+ long nominal = (long) cinfo->restart_in_rows * (long) cinfo->MCUs_per_row;
+ cinfo->restart_interval = (unsigned int) MIN(nominal, 65535L);
}
}
/*
- * This is the main entry point to the JPEG compressor.
+ * Master selection of compression modules.
+ * This is done once at the start of processing an image. We determine
+ * which modules will be used and give them appropriate initialization calls.
*/
+LOCAL void
+master_selection (j_compress_ptr cinfo)
+{
+ my_master_ptr master = (my_master_ptr) cinfo->master;
+
+ initial_setup(cinfo);
+ master->pass_number = 0;
+
+ /* There's not a lot of smarts here right now, but it'll get more
+ * complicated when we have multiple implementations available...
+ */
+
+ /* Preprocessing */
+ if (! cinfo->raw_data_in) {
+ jinit_color_converter(cinfo);
+ jinit_downsampler(cinfo);
+ jinit_c_prep_controller(cinfo, FALSE /* never need full buffer here */);
+ }
+ /* Forward DCT */
+ jinit_forward_dct(cinfo);
+ /* Entropy encoding: either Huffman or arithmetic coding. */
+ if (cinfo->arith_code) {
+#ifdef C_ARITH_CODING_SUPPORTED
+ jinit_arith_encoder(cinfo);
+#else
+ ERREXIT(cinfo, JERR_ARITH_NOTIMPL);
+#endif
+ } else
+ jinit_huff_encoder(cinfo);
+
+ /* For now, a full buffer is needed only for Huffman optimization. */
+ jinit_c_coef_controller(cinfo, cinfo->optimize_coding);
+ jinit_c_main_controller(cinfo, FALSE /* never need full buffer here */);
+
+ jinit_marker_writer(cinfo);
+
+ /* We can now tell the memory manager to allocate virtual arrays. */
+ (*cinfo->mem->realize_virt_arrays) ((j_common_ptr) cinfo);
+
+ /* Write the datastream header (SOI) immediately.
+ * Frame and scan headers are postponed till later.
+ * This lets application insert special markers after the SOI.
+ */
+ (*cinfo->marker->write_file_header) (cinfo);
+}
+
+
+/*
+ * Per-pass setup.
+ * This is called at the beginning of each pass. We determine which modules
+ * will be active during this pass and give them appropriate start_pass calls.
+ * We also set is_last_pass to indicate whether any more passes will be
+ * required.
+ */
+
+METHODDEF void
+prepare_for_pass (j_compress_ptr cinfo)
+{
+ my_master_ptr master = (my_master_ptr) cinfo->master;
+ int ci;
+ int npasses;
+
+ /* ???? JUST A QUICK CROCK FOR NOW ??? */
+
+ /* For now, handle only single interleaved output scan; */
+ /* we support two passes for Huffman optimization. */
+
+ /* Prepare for single scan containing all components */
+ if (cinfo->num_components > MAX_COMPS_IN_SCAN)
+ ERREXIT2(cinfo, JERR_COMPONENT_COUNT, cinfo->num_components,
+ MAX_COMPS_IN_SCAN);
+ cinfo->comps_in_scan = cinfo->num_components;
+ for (ci = 0; ci < cinfo->num_components; ci++) {
+ cinfo->cur_comp_info[ci] = &cinfo->comp_info[ci];
+ }
+
+ per_scan_setup(cinfo);
+
+ if (! cinfo->optimize_coding) {
+ /* Standard single-pass case */
+ npasses = 1;
+ master->pub.call_pass_startup = TRUE;
+ master->pub.is_last_pass = TRUE;
+ if (! cinfo->raw_data_in) {
+ (*cinfo->cconvert->start_pass) (cinfo);
+ (*cinfo->downsample->start_pass) (cinfo);
+ (*cinfo->prep->start_pass) (cinfo, JBUF_PASS_THRU);
+ }
+ (*cinfo->fdct->start_pass) (cinfo);
+ (*cinfo->entropy->start_pass) (cinfo, FALSE);
+ (*cinfo->coef->start_pass) (cinfo, JBUF_PASS_THRU);
+ (*cinfo->main->start_pass) (cinfo, JBUF_PASS_THRU);
+ } else {
+ npasses = 2;
+ switch (master->pass_number) {
+ case 0:
+ /* Huffman optimization: run all modules, gather statistics */
+ master->pub.call_pass_startup = FALSE;
+ master->pub.is_last_pass = FALSE;
+ if (! cinfo->raw_data_in) {
+ (*cinfo->cconvert->start_pass) (cinfo);
+ (*cinfo->downsample->start_pass) (cinfo);
+ (*cinfo->prep->start_pass) (cinfo, JBUF_PASS_THRU);
+ }
+ (*cinfo->fdct->start_pass) (cinfo);
+ (*cinfo->entropy->start_pass) (cinfo, TRUE);
+ (*cinfo->coef->start_pass) (cinfo, JBUF_SAVE_AND_PASS);
+ (*cinfo->main->start_pass) (cinfo, JBUF_PASS_THRU);
+ break;
+ case 1:
+ /* Second pass: reread data from coefficient buffer */
+ master->pub.is_last_pass = TRUE;
+ (*cinfo->entropy->start_pass) (cinfo, FALSE);
+ (*cinfo->coef->start_pass) (cinfo, JBUF_CRANK_DEST);
+ /* We emit frame/scan headers now */
+ (*cinfo->marker->write_frame_header) (cinfo);
+ (*cinfo->marker->write_scan_header) (cinfo);
+ break;
+ }
+ }
+
+ /* Set up progress monitor's pass info if present */
+ if (cinfo->progress != NULL) {
+ cinfo->progress->completed_passes = master->pass_number;
+ cinfo->progress->total_passes = npasses;
+ }
+
+ master->pass_number++;
+}
+
+
+/*
+ * Special start-of-pass hook.
+ * This is called by jpeg_write_scanlines if call_pass_startup is TRUE.
+ * In single-pass processing, we need this hook because we don't want to
+ * write frame/scan headers during jpeg_start_compress; we want to let the
+ * application write COM markers etc. between jpeg_start_compress and the
+ * jpeg_write_scanlines loop.
+ * In multi-pass processing, this routine is not used.
+ */
+
+METHODDEF void
+pass_startup (j_compress_ptr cinfo)
+{
+ cinfo->master->call_pass_startup = FALSE; /* reset flag so call only once */
+
+ (*cinfo->marker->write_frame_header) (cinfo);
+ (*cinfo->marker->write_scan_header) (cinfo);
+}
+
+
+/*
+ * Finish up at end of pass.
+ */
+
+METHODDEF void
+finish_pass_master (j_compress_ptr cinfo)
+{
+ /* More complex logic later ??? */
+
+ /* The entropy coder needs an end-of-pass call, either to analyze
+ * statistics or to flush its output buffer.
+ */
+ (*cinfo->entropy->finish_pass) (cinfo);
+}
+
+
+/*
+ * Initialize master compression control.
+ * This creates my own subrecord and also performs the master selection phase,
+ * which causes other modules to create their subrecords.
+ */
GLOBAL void
-jpeg_compress (compress_info_ptr cinfo)
+jinit_master_compress (j_compress_ptr cinfo)
{
- /* Init pass counts to 0 --- total_passes is adjusted in method selection */
- cinfo->total_passes = 0;
- cinfo->completed_passes = 0;
+ my_master_ptr master;
- /* Read the input file header: determine image size & component count.
- * NOTE: the user interface must have initialized the input_init method
- * pointer (eg, by calling jselrppm) before calling me.
- * The other file reading methods (get_input_row etc.) were probably
- * set at the same time, but could be set up by input_init itself,
- * or by c_ui_method_selection.
- */
- (*cinfo->methods->input_init) (cinfo);
+ master = (my_master_ptr)
+ (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
+ SIZEOF(my_comp_master));
+ cinfo->master = (struct jpeg_comp_master *) master;
+ master->pub.prepare_for_pass = prepare_for_pass;
+ master->pub.pass_startup = pass_startup;
+ master->pub.finish_pass = finish_pass_master;
- /* Give UI a chance to adjust compression parameters and select */
- /* output file format based on results of input_init. */
- (*cinfo->methods->c_ui_method_selection) (cinfo);
-
- /* Now select methods for compression steps. */
- initial_setup(cinfo);
- c_initial_method_selection(cinfo);
-
- /* Initialize the output file & other modules as needed */
- /* (entropy_encoder is inited by pipeline controller) */
-
- (*cinfo->methods->colorin_init) (cinfo);
- (*cinfo->methods->write_file_header) (cinfo);
-
- /* And let the pipeline controller do the rest. */
- (*cinfo->methods->c_pipeline_controller) (cinfo);
-
- /* Finish output file, release working storage, etc */
- (*cinfo->methods->write_file_trailer) (cinfo);
- (*cinfo->methods->colorin_term) (cinfo);
- (*cinfo->methods->input_term) (cinfo);
-
- (*cinfo->emethods->free_all) ();
-
- /* My, that was easy, wasn't it? */
+ master_selection(cinfo);
}