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- /* Copyright (C) 1994, 1995, 1997, 1998, 1999 Aladdin Enterprises. All rights reserved.
-
- This file is part of AFPL Ghostscript.
-
- AFPL Ghostscript is distributed with NO WARRANTY OF ANY KIND. No author or
- distributor accepts any responsibility for the consequences of using it, or
- for whether it serves any particular purpose or works at all, unless he or
- she says so in writing. Refer to the Aladdin Free Public License (the
- "License") for full details.
-
- Every copy of AFPL Ghostscript must include a copy of the License, normally
- in a plain ASCII text file named PUBLIC. The License grants you the right
- to copy, modify and redistribute AFPL Ghostscript, but only under certain
- conditions described in the License. Among other things, the License
- requires that the copyright notice and this notice be preserved on all
- copies.
- */
-
- /*$Id: sdctd.c,v 1.2 2000/09/19 19:00:49 lpd Exp $ */
- /* DCT decoding filter stream */
- #include "memory_.h"
- #include "stdio_.h"
- #include "jpeglib_.h"
- #include "jerror_.h"
- #include "gdebug.h"
- #include "gsmemory.h" /* for gsmalloc.h */
- #include "gsmalloc.h" /* for gs_memory_default */
- #include "strimpl.h"
- #include "sdct.h"
- #include "sjpeg.h"
-
- /* ------ DCTDecode ------ */
-
- /* JPEG source manager procedures */
- private void
- dctd_init_source(j_decompress_ptr dinfo)
- {
- }
- static const JOCTET fake_eoi[2] =
- {0xFF, JPEG_EOI};
- private boolean
- dctd_fill_input_buffer(j_decompress_ptr dinfo)
- {
- jpeg_decompress_data *jddp =
- (jpeg_decompress_data *) ((char *)dinfo -
- offset_of(jpeg_decompress_data, dinfo));
-
- if (!jddp->input_eod)
- return FALSE; /* normal case: suspend processing */
- /* Reached end of source data without finding EOI */
- WARNMS(dinfo, JWRN_JPEG_EOF);
- /* Insert a fake EOI marker */
- dinfo->src->next_input_byte = fake_eoi;
- dinfo->src->bytes_in_buffer = 2;
- jddp->faked_eoi = true; /* so process routine doesn't use next_input_byte */
- return TRUE;
- }
- private void
- dctd_skip_input_data(j_decompress_ptr dinfo, long num_bytes)
- {
- struct jpeg_source_mgr *src = dinfo->src;
- jpeg_decompress_data *jddp =
- (jpeg_decompress_data *) ((char *)dinfo -
- offset_of(jpeg_decompress_data, dinfo));
-
- if (num_bytes > 0) {
- if (num_bytes > src->bytes_in_buffer) {
- jddp->skip += num_bytes - src->bytes_in_buffer;
- src->next_input_byte += src->bytes_in_buffer;
- src->bytes_in_buffer = 0;
- return;
- }
- src->next_input_byte += num_bytes;
- src->bytes_in_buffer -= num_bytes;
- }
- }
- private void
- dctd_term_source(j_decompress_ptr dinfo)
- {
- }
-
- /* Set the defaults for the DCTDecode filter. */
- private void
- s_DCTD_set_defaults(stream_state * st)
- {
- s_DCT_set_defaults(st);
- }
-
- /* Initialize DCTDecode filter */
- private int
- s_DCTD_init(stream_state * st)
- {
- stream_DCT_state *const ss = (stream_DCT_state *) st;
- struct jpeg_source_mgr *src = &ss->data.decompress->source;
-
- src->init_source = dctd_init_source;
- src->fill_input_buffer = dctd_fill_input_buffer;
- src->skip_input_data = dctd_skip_input_data;
- src->term_source = dctd_term_source;
- src->resync_to_restart = jpeg_resync_to_restart; /* use default method */
- ss->data.common->memory = ss->jpeg_memory;
- ss->data.decompress->dinfo.src = src;
- ss->data.decompress->skip = 0;
- ss->data.decompress->input_eod = false;
- ss->data.decompress->faked_eoi = false;
- ss->phase = 0;
- return 0;
- }
-
- /* Process a buffer */
- private int
- s_DCTD_process(stream_state * st, stream_cursor_read * pr,
- stream_cursor_write * pw, bool last)
- {
- stream_DCT_state *const ss = (stream_DCT_state *) st;
- jpeg_decompress_data *jddp = ss->data.decompress;
- struct jpeg_source_mgr *src = jddp->dinfo.src;
- int code;
-
- if_debug3('w', "[wdd]process avail=%u, skip=%u, last=%d\n",
- (uint) (pr->limit - pr->ptr), (uint) jddp->skip, last);
- if (jddp->skip != 0) {
- long avail = pr->limit - pr->ptr;
-
- if (avail < jddp->skip) {
- jddp->skip -= avail;
- pr->ptr = pr->limit;
- if (!last)
- return 0; /* need more data */
- jddp->skip = 0; /* don't skip past input EOD */
- }
- pr->ptr += jddp->skip;
- jddp->skip = 0;
- }
- src->next_input_byte = pr->ptr + 1;
- src->bytes_in_buffer = pr->limit - pr->ptr;
- jddp->input_eod = last;
- switch (ss->phase) {
- case 0: /* not initialized yet */
- /*
- * Adobe implementations seem to ignore leading garbage bytes,
- * even though neither the standard nor Adobe's own
- * documentation mention this.
- */
- while (pr->ptr < pr->limit && pr->ptr[1] != 0xff)
- pr->ptr++;
- if (pr->ptr == pr->limit)
- return 0;
- src->next_input_byte = pr->ptr + 1;
- src->bytes_in_buffer = pr->limit - pr->ptr;
- ss->phase = 1;
- /* falls through */
- case 1: /* reading header markers */
- if ((code = gs_jpeg_read_header(ss, TRUE)) < 0)
- return ERRC;
- pr->ptr =
- (jddp->faked_eoi ? pr->limit : src->next_input_byte - 1);
- switch (code) {
- case JPEG_SUSPENDED:
- return 0;
- /*case JPEG_HEADER_OK: */
- }
- /* If we have a ColorTransform parameter, and it's not
- * overridden by an Adobe marker in the data, set colorspace.
- */
- if (ss->ColorTransform >= 0 &&
- !jddp->dinfo.saw_Adobe_marker) {
- switch (jddp->dinfo.num_components) {
- case 3:
- jddp->dinfo.jpeg_color_space =
- (ss->ColorTransform ? JCS_YCbCr : JCS_RGB);
- /* out_color_space will default to JCS_RGB */
- break;
- case 4:
- jddp->dinfo.jpeg_color_space =
- (ss->ColorTransform ? JCS_YCCK : JCS_CMYK);
- /* out_color_space will default to JCS_CMYK */
- break;
- }
- }
- ss->phase = 2;
- /* falls through */
- case 2: /* start_decompress */
- if ((code = gs_jpeg_start_decompress(ss)) < 0)
- return ERRC;
- pr->ptr =
- (jddp->faked_eoi ? pr->limit : src->next_input_byte - 1);
- if (code == 0)
- return 0;
- ss->scan_line_size =
- jddp->dinfo.output_width * jddp->dinfo.output_components;
- if_debug4('w', "[wdd]width=%u, components=%d, scan_line_size=%u, min_out_size=%u\n",
- jddp->dinfo.output_width,
- jddp->dinfo.output_components,
- ss->scan_line_size, jddp->template.min_out_size);
- if (ss->scan_line_size > (uint) jddp->template.min_out_size) {
- /* Create a spare buffer for oversize scanline */
- jddp->scanline_buffer =
- gs_alloc_bytes_immovable(jddp->memory,
- ss->scan_line_size,
- "s_DCTD_process(scanline_buffer)");
- if (jddp->scanline_buffer == NULL)
- return ERRC;
- }
- jddp->bytes_in_scanline = 0;
- ss->phase = 3;
- /* falls through */
- case 3: /* reading data */
- dumpbuffer:
- if (jddp->bytes_in_scanline != 0) {
- uint avail = pw->limit - pw->ptr;
- uint tomove = min(jddp->bytes_in_scanline,
- avail);
-
- if_debug2('w', "[wdd]moving %u/%u\n",
- tomove, avail);
- memcpy(pw->ptr + 1, jddp->scanline_buffer +
- (ss->scan_line_size - jddp->bytes_in_scanline),
- tomove);
- pw->ptr += tomove;
- jddp->bytes_in_scanline -= tomove;
- if (jddp->bytes_in_scanline != 0)
- return 1; /* need more room */
- }
- while (jddp->dinfo.output_height > jddp->dinfo.output_scanline) {
- int read;
- byte *samples;
-
- if (jddp->scanline_buffer != NULL)
- samples = jddp->scanline_buffer;
- else {
- if ((uint) (pw->limit - pw->ptr) < ss->scan_line_size)
- return 1; /* need more room */
- samples = pw->ptr + 1;
- }
- read = gs_jpeg_read_scanlines(ss, &samples, 1);
- if (read < 0)
- return ERRC;
- if_debug3('w', "[wdd]read returns %d, used=%u, faked_eoi=%d\n",
- read,
- (uint) (src->next_input_byte - 1 - pr->ptr),
- (int)jddp->faked_eoi);
- pr->ptr =
- (jddp->faked_eoi ? pr->limit : src->next_input_byte - 1);
- if (!read)
- return 0; /* need more data */
- if (jddp->scanline_buffer != NULL) {
- jddp->bytes_in_scanline = ss->scan_line_size;
- goto dumpbuffer;
- }
- pw->ptr += ss->scan_line_size;
- }
- ss->phase = 4;
- /* falls through */
- case 4: /* end of image; scan for EOI */
- if ((code = gs_jpeg_finish_decompress(ss)) < 0)
- return ERRC;
- pr->ptr =
- (jddp->faked_eoi ? pr->limit : src->next_input_byte - 1);
- if (code == 0)
- return 0;
- ss->phase = 5;
- /* falls through */
- case 5: /* we are DONE */
- return EOFC;
- }
- /* Default case can't happen.... */
- return ERRC;
- }
-
- /* Release the stream */
- private void
- s_DCTD_release(stream_state * st)
- {
- stream_DCT_state *const ss = (stream_DCT_state *) st;
-
- gs_jpeg_destroy(ss);
- if (ss->data.decompress->scanline_buffer != NULL)
- gs_free_object(ss->data.common->memory,
- ss->data.decompress->scanline_buffer,
- "s_DCTD_release(scanline_buffer)");
- gs_free_object(ss->data.common->memory, ss->data.decompress,
- "s_DCTD_release");
- /* Switch the template pointer back in case we still need it. */
- st->template = &s_DCTD_template;
- }
-
- /* Stream template */
- const stream_template s_DCTD_template =
- {&st_DCT_state, s_DCTD_init, s_DCTD_process, 2000, 4000, s_DCTD_release,
- s_DCTD_set_defaults
- };
-