start_input_pass (j_decompress_ptr cinfo)
{
per_scan_setup(cinfo);
(*cinfo->codec->start_input_pass) (cinfo);
cinfo->inputctl->consume_input = cinfo->codec->consume_data;
}
jpeg_decompress_per_scan_setup(j_decompress_ptr cinfo)
{
per_scan_setup(cinfo);
}
prepare_for_pass (j_compress_ptr cinfo)
{
my_master_ptr master = (my_master_ptr) cinfo->master;
switch (master->pass_type) {
case main_pass:
/* Initial pass: will collect input data, and do either Huffman
* optimization or data output for the first scan.
*/
select_scan_parameters(cinfo);
per_scan_setup(cinfo);
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, cinfo->optimize_coding);
(*cinfo->coef->start_pass) (cinfo,
(master->total_passes > 1 ?
JBUF_SAVE_AND_PASS : JBUF_PASS_THRU));
(*cinfo->main->start_pass) (cinfo, JBUF_PASS_THRU);
if (cinfo->optimize_coding) {
/* No immediate data output; postpone writing frame/scan headers */
master->pub.call_pass_startup = FALSE;
} else {
/* Will write frame/scan headers at first jpeg_write_scanlines call */
master->pub.call_pass_startup = TRUE;
}
break;
#ifdef ENTROPY_OPT_SUPPORTED
case huff_opt_pass:
/* Do Huffman optimization for a scan after the first one. */
select_scan_parameters(cinfo);
per_scan_setup(cinfo);
if (cinfo->Ss != 0 || cinfo->Ah == 0 || cinfo->arith_code) {
(*cinfo->entropy->start_pass) (cinfo, TRUE);
(*cinfo->coef->start_pass) (cinfo, JBUF_CRANK_DEST);
master->pub.call_pass_startup = FALSE;
break;
}
/* Special case: Huffman DC refinement scans need no Huffman table
* and therefore we can skip the optimization pass for them.
*/
master->pass_type = output_pass;
master->pass_number++;
/*FALLTHROUGH*/
#endif
case output_pass:
/* Do a data-output pass. */
/* We need not repeat per-scan setup if prior optimization pass did it. */
if (! cinfo->optimize_coding) {
select_scan_parameters(cinfo);
per_scan_setup(cinfo);
}
if (cinfo->optimize_scans) {
master->saved_dest = cinfo->dest;
cinfo->dest = NULL;
master->scan_size[master->scan_number] = 0;
jpeg_mem_dest(cinfo, &master->scan_buffer[master->scan_number], &master->scan_size[master->scan_number]);
(*cinfo->dest->init_destination)(cinfo);
}
(*cinfo->entropy->start_pass) (cinfo, FALSE);
(*cinfo->coef->start_pass) (cinfo, JBUF_CRANK_DEST);
/* We emit frame/scan headers now */
if (master->scan_number == 0)
(*cinfo->marker->write_frame_header) (cinfo);
(*cinfo->marker->write_scan_header) (cinfo);
master->pub.call_pass_startup = FALSE;
break;
default:
ERREXIT(cinfo, JERR_NOT_COMPILED);
}
master->pub.is_last_pass = (master->pass_number == master->total_passes-1);
/* Set up progress monitor's pass info if present */
if (cinfo->progress != NULL) {
cinfo->progress->completed_passes = master->pass_number;
cinfo->progress->total_passes = master->total_passes;
}
}
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++;
}
