/src/gdal/build/frmts/jpeg/libjpeg12/jdpostct12.c

Source (jump to first uncovered line)
/*
 * jdpostct.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 decompression postprocessing controller.
 * This controller manages the upsampling, color conversion, and color
 * quantization/reduction steps; specifically, it controls the buffering
 * between upsample/color conversion and color quantization/reduction.
 *
 * If no color quantization/reduction is required, then this module has no
 * work to do, and it just hands off to the upsample/color conversion code.
 * An integrated upsample/convert/quantize process would replace this module
 * entirely.
 */

#define JPEG_INTERNALS
#include "jinclude.h"
#include "jpeglib.h"

#include "cpl_port.h"

/* Private buffer controller object */

typedef struct {
  struct jpeg_d_post_controller pub; /* public fields */

  /* Color quantization source buffer: this holds output data from
   * the upsample/color conversion step to be passed to the quantizer.
   * For two-pass color quantization, we need a full-image buffer;
   * for one-pass operation, a strip buffer is sufficient.
   */
  jvirt_sarray_ptr whole_image; /* virtual array, or NULL if one-pass */
  JSAMPARRAY buffer;    /* strip buffer, or current strip of virtual */
  JDIMENSION strip_height;  /* buffer size in rows */
  /* for two-pass mode only: */
  JDIMENSION starting_row;  /* row # of first row in current strip */
  JDIMENSION next_row;    /* index of next row to fill/empty in strip */
} my_post_controller;

typedef my_post_controller * my_post_ptr;


/* Forward declarations */
METHODDEF(void) post_process_1pass
  JPP((j_decompress_ptr cinfo,
       JSAMPIMAGE input_buf, JDIMENSION *in_row_group_ctr,
       JDIMENSION in_row_groups_avail,
       JSAMPARRAY output_buf, JDIMENSION *out_row_ctr,
       JDIMENSION out_rows_avail));
#ifdef QUANT_2PASS_SUPPORTED
METHODDEF(void) post_process_prepass
  JPP((j_decompress_ptr cinfo,
       JSAMPIMAGE input_buf, JDIMENSION *in_row_group_ctr,
       JDIMENSION in_row_groups_avail,
       JSAMPARRAY output_buf, JDIMENSION *out_row_ctr,
       JDIMENSION out_rows_avail));
METHODDEF(void) post_process_2pass
  JPP((j_decompress_ptr cinfo,
       JSAMPIMAGE input_buf, JDIMENSION *in_row_group_ctr,
       JDIMENSION in_row_groups_avail,
       JSAMPARRAY output_buf, JDIMENSION *out_row_ctr,
       JDIMENSION out_rows_avail));
#endif


/*
 * Initialize for a processing pass.
 */

METHODDEF(void)
start_pass_dpost (j_decompress_ptr cinfo, J_BUF_MODE pass_mode)
{
  my_post_ptr post = (my_post_ptr) cinfo->post;

  switch (pass_mode) {
  case JBUF_PASS_THRU:
    if (cinfo->quantize_colors) {
      /* Single-pass processing with color quantization. */
      post->pub.post_process_data = post_process_1pass;
      /* We could be doing buffered-image output before starting a 2-pass
       * color quantization; in that case, jinit_d_post_controller did not
       * allocate a strip buffer.  Use the virtual-array buffer as workspace.
       */
      if (post->buffer == NULL) {
  post->buffer = (*cinfo->mem->access_virt_sarray)
    ((j_common_ptr) cinfo, post->whole_image,
     (JDIMENSION) 0, post->strip_height, TRUE);
      }
    } else {
      /* For single-pass processing without color quantization,
       * I have no work to do; just call the upsampler directly.
       */
      post->pub.post_process_data = cinfo->upsample->upsample;
    }
    break;
#ifdef QUANT_2PASS_SUPPORTED
  case JBUF_SAVE_AND_PASS:
    /* First pass of 2-pass quantization */
    if (post->whole_image == NULL)
      ERREXIT(cinfo, JERR_BAD_BUFFER_MODE);
    post->pub.post_process_data = post_process_prepass;
    break;
  case JBUF_CRANK_DEST:
    /* Second pass of 2-pass quantization */
    if (post->whole_image == NULL)
      ERREXIT(cinfo, JERR_BAD_BUFFER_MODE);
    post->pub.post_process_data = post_process_2pass;
    break;
#endif /* QUANT_2PASS_SUPPORTED */
  default:
    ERREXIT(cinfo, JERR_BAD_BUFFER_MODE);
    break;
  }
  post->starting_row = post->next_row = 0;
}


/*
 * Process some data in the one-pass (strip buffer) case.
 * This is used for color precision reduction as well as one-pass quantization.
 */

METHODDEF(void)
post_process_1pass (j_decompress_ptr cinfo,
        JSAMPIMAGE input_buf, JDIMENSION *in_row_group_ctr,
        JDIMENSION in_row_groups_avail,
        JSAMPARRAY output_buf, JDIMENSION *out_row_ctr,
        JDIMENSION out_rows_avail)
{
  my_post_ptr post = (my_post_ptr) cinfo->post;
  JDIMENSION num_rows, max_rows;

  /* Fill the buffer, but not more than what we can dump out in one go. */
  /* Note we rely on the upsampler to detect bottom of image. */
  max_rows = out_rows_avail - *out_row_ctr;
  if (max_rows > post->strip_height)
    max_rows = post->strip_height;
  num_rows = 0;
  (*cinfo->upsample->upsample) (cinfo,
    input_buf, in_row_group_ctr, in_row_groups_avail,
    post->buffer, &num_rows, max_rows);
  /* Quantize and emit data. */
  (*cinfo->cquantize->color_quantize) (cinfo,
    post->buffer, output_buf + *out_row_ctr, (int) num_rows);
  *out_row_ctr += num_rows;
}


#ifdef QUANT_2PASS_SUPPORTED

/*
 * Process some data in the first pass of 2-pass quantization.
 */

METHODDEF(void)
post_process_prepass (j_decompress_ptr cinfo,
          JSAMPIMAGE input_buf, JDIMENSION *in_row_group_ctr,
          JDIMENSION in_row_groups_avail,
          CPL_UNUSED JSAMPARRAY output_buf, JDIMENSION *out_row_ctr,
          CPL_UNUSED JDIMENSION out_rows_avail)
{
  my_post_ptr post = (my_post_ptr) cinfo->post;
  JDIMENSION old_next_row, num_rows;

  /* Reposition virtual buffer if at start of strip. */
  if (post->next_row == 0) {
    post->buffer = (*cinfo->mem->access_virt_sarray)
  ((j_common_ptr) cinfo, post->whole_image,
   post->starting_row, post->strip_height, TRUE);
  }

  /* Upsample some data (up to a strip height's worth). */
  old_next_row = post->next_row;
  (*cinfo->upsample->upsample) (cinfo,
    input_buf, in_row_group_ctr, in_row_groups_avail,
    post->buffer, &post->next_row, post->strip_height);

  /* Allow quantizer to scan new data.  No data is emitted, */
  /* but we advance out_row_ctr so outer loop can tell when we're done. */
  if (post->next_row > old_next_row) {
    num_rows = post->next_row - old_next_row;
    (*cinfo->cquantize->color_quantize) (cinfo, post->buffer + old_next_row,
           (JSAMPARRAY) NULL, (int) num_rows);
    *out_row_ctr += num_rows;
  }

  /* Advance if we filled the strip. */
  if (post->next_row >= post->strip_height) {
    post->starting_row += post->strip_height;
    post->next_row = 0;
  }
}


/*
 * Process some data in the second pass of 2-pass quantization.
 */

METHODDEF(void)
post_process_2pass (j_decompress_ptr cinfo,
        CPL_UNUSED JSAMPIMAGE input_buf, CPL_UNUSED JDIMENSION *in_row_group_ctr,
        CPL_UNUSED JDIMENSION in_row_groups_avail,
        JSAMPARRAY output_buf, JDIMENSION *out_row_ctr,
        JDIMENSION out_rows_avail)
{
  my_post_ptr post = (my_post_ptr) cinfo->post;
  JDIMENSION num_rows, max_rows;

  /* Reposition virtual buffer if at start of strip. */
  if (post->next_row == 0) {
    post->buffer = (*cinfo->mem->access_virt_sarray)
  ((j_common_ptr) cinfo, post->whole_image,
   post->starting_row, post->strip_height, FALSE);
  }

  /* Determine number of rows to emit. */
  num_rows = post->strip_height - post->next_row; /* available in strip */
  max_rows = out_rows_avail - *out_row_ctr; /* available in output area */
  if (num_rows > max_rows)
    num_rows = max_rows;
  /* We have to check bottom of image here, can't depend on upsampler. */
  max_rows = cinfo->output_height - post->starting_row;
  if (num_rows > max_rows)
    num_rows = max_rows;

  /* Quantize and emit data. */
  (*cinfo->cquantize->color_quantize) (cinfo,
    post->buffer + post->next_row, output_buf + *out_row_ctr,
    (int) num_rows);
  *out_row_ctr += num_rows;

  /* Advance if we filled the strip. */
  post->next_row += num_rows;
  if (post->next_row >= post->strip_height) {
    post->starting_row += post->strip_height;
    post->next_row = 0;
  }
}

#endif /* QUANT_2PASS_SUPPORTED */


/*
 * Initialize postprocessing controller.
 */

GLOBAL(void)
jinit_d_post_controller (j_decompress_ptr cinfo, boolean need_full_buffer)
{
  my_post_ptr post;

  post = (my_post_ptr)
    (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
        SIZEOF(my_post_controller));
  cinfo->post = (struct jpeg_d_post_controller *) post;
  post->pub.start_pass = start_pass_dpost;
  post->whole_image = NULL; /* flag for no virtual arrays */
  post->buffer = NULL;    /* flag for no strip buffer */

  /* Create the quantization buffer, if needed */
  if (cinfo->quantize_colors) {
    /* The buffer strip height is max_v_samp_factor, which is typically
     * an efficient number of rows for upsampling to return.
     * (In the presence of output rescaling, we might want to be smarter?)
     */
    post->strip_height = (JDIMENSION) cinfo->max_v_samp_factor;
    if (need_full_buffer) {
      /* Two-pass color quantization: need full-image storage. */
      /* We round up the number of rows to a multiple of the strip height. */
#ifdef QUANT_2PASS_SUPPORTED
      post->whole_image = (*cinfo->mem->request_virt_sarray)
  ((j_common_ptr) cinfo, JPOOL_IMAGE, FALSE,
   cinfo->output_width * cinfo->out_color_components,
   (JDIMENSION) jround_up((long) cinfo->output_height,
        (long) post->strip_height),
   post->strip_height);
#else
      ERREXIT(cinfo, JERR_BAD_BUFFER_MODE);
#endif /* QUANT_2PASS_SUPPORTED */
    } else {
      /* One-pass color quantization: just make a strip buffer. */
      post->buffer = (*cinfo->mem->alloc_sarray)
  ((j_common_ptr) cinfo, JPOOL_IMAGE,
   cinfo->output_width * cinfo->out_color_components,
   post->strip_height);
    }
  }
}

Coverage Report

Created: 2025-06-22 06:59

Line	Count	Source (jump to first uncovered line)
1		/*
2		* jdpostct.c
3		*
4		* Copyright (C) 1994-1996, Thomas G. Lane.
5		* This file is part of the Independent JPEG Group's software.
6		* For conditions of distribution and use, see the accompanying README file.
7		*
8		* This file contains the decompression postprocessing controller.
9		* This controller manages the upsampling, color conversion, and color
10		* quantization/reduction steps; specifically, it controls the buffering
11		* between upsample/color conversion and color quantization/reduction.
12		*
13		* If no color quantization/reduction is required, then this module has no
14		* work to do, and it just hands off to the upsample/color conversion code.
15		* An integrated upsample/convert/quantize process would replace this module
16		* entirely.
17		*/
18
19		#define JPEG_INTERNALS
20		#include "jinclude.h"
21		#include "jpeglib.h"
22
23		#include "cpl_port.h"
24
25		/* Private buffer controller object */
26
27		typedef struct {
28		struct jpeg_d_post_controller pub; /* public fields */
29
30		/* Color quantization source buffer: this holds output data from
31		* the upsample/color conversion step to be passed to the quantizer.
32		* For two-pass color quantization, we need a full-image buffer;
33		* for one-pass operation, a strip buffer is sufficient.
34		*/
35		jvirt_sarray_ptr whole_image; /* virtual array, or NULL if one-pass */
36		JSAMPARRAY buffer; /* strip buffer, or current strip of virtual */
37		JDIMENSION strip_height; /* buffer size in rows */
38		/* for two-pass mode only: */
39		JDIMENSION starting_row; /* row # of first row in current strip */
40		JDIMENSION next_row; /* index of next row to fill/empty in strip */
41		} my_post_controller;
42
43		typedef my_post_controller * my_post_ptr;
44
45
46		/* Forward declarations */
47		METHODDEF(void) post_process_1pass
48		JPP((j_decompress_ptr cinfo,
49		JSAMPIMAGE input_buf, JDIMENSION *in_row_group_ctr,
50		JDIMENSION in_row_groups_avail,
51		JSAMPARRAY output_buf, JDIMENSION *out_row_ctr,
52		JDIMENSION out_rows_avail));
53		#ifdef QUANT_2PASS_SUPPORTED
54		METHODDEF(void) post_process_prepass
55		JPP((j_decompress_ptr cinfo,
56		JSAMPIMAGE input_buf, JDIMENSION *in_row_group_ctr,
57		JDIMENSION in_row_groups_avail,
58		JSAMPARRAY output_buf, JDIMENSION *out_row_ctr,
59		JDIMENSION out_rows_avail));
60		METHODDEF(void) post_process_2pass
61		JPP((j_decompress_ptr cinfo,
62		JSAMPIMAGE input_buf, JDIMENSION *in_row_group_ctr,
63		JDIMENSION in_row_groups_avail,
64		JSAMPARRAY output_buf, JDIMENSION *out_row_ctr,
65		JDIMENSION out_rows_avail));
66		#endif
67
68
69		/*
70		* Initialize for a processing pass.
71		*/
72
73		METHODDEF(void)
74		start_pass_dpost (j_decompress_ptr cinfo, J_BUF_MODE pass_mode)
75	0	{
76	0	my_post_ptr post = (my_post_ptr) cinfo->post;
77
78	0	switch (pass_mode) {
79	0	case JBUF_PASS_THRU:
80	0	if (cinfo->quantize_colors) {
81		/* Single-pass processing with color quantization. */
82	0	post->pub.post_process_data = post_process_1pass;
83		/* We could be doing buffered-image output before starting a 2-pass
84		* color quantization; in that case, jinit_d_post_controller did not
85		* allocate a strip buffer. Use the virtual-array buffer as workspace.
86		*/
87	0	if (post->buffer == NULL) {
88	0	post->buffer = (*cinfo->mem->access_virt_sarray)
89	0	((j_common_ptr) cinfo, post->whole_image,
90	0	(JDIMENSION) 0, post->strip_height, TRUE);
91	0	}
92	0	} else {
93		/* For single-pass processing without color quantization,
94		* I have no work to do; just call the upsampler directly.
95		*/
96	0	post->pub.post_process_data = cinfo->upsample->upsample;
97	0	}
98	0	break;
99	0	#ifdef QUANT_2PASS_SUPPORTED
100	0	case JBUF_SAVE_AND_PASS:
101		/* First pass of 2-pass quantization */
102	0	if (post->whole_image == NULL)
103	0	ERREXIT(cinfo, JERR_BAD_BUFFER_MODE);
104	0	post->pub.post_process_data = post_process_prepass;
105	0	break;
106	0	case JBUF_CRANK_DEST:
107		/* Second pass of 2-pass quantization */
108	0	if (post->whole_image == NULL)
109	0	ERREXIT(cinfo, JERR_BAD_BUFFER_MODE);
110	0	post->pub.post_process_data = post_process_2pass;
111	0	break;
112	0	#endif /* QUANT_2PASS_SUPPORTED */
113	0	default:
114	0	ERREXIT(cinfo, JERR_BAD_BUFFER_MODE);
115	0	break;
116	0	}
117	0	post->starting_row = post->next_row = 0;
118	0	}
119
120
121		/*
122		* Process some data in the one-pass (strip buffer) case.
123		* This is used for color precision reduction as well as one-pass quantization.
124		*/
125
126		METHODDEF(void)
127		post_process_1pass (j_decompress_ptr cinfo,
128		JSAMPIMAGE input_buf, JDIMENSION *in_row_group_ctr,
129		JDIMENSION in_row_groups_avail,
130		JSAMPARRAY output_buf, JDIMENSION *out_row_ctr,
131		JDIMENSION out_rows_avail)
132	0	{
133	0	my_post_ptr post = (my_post_ptr) cinfo->post;
134	0	JDIMENSION num_rows, max_rows;
135
136		/* Fill the buffer, but not more than what we can dump out in one go. */
137		/* Note we rely on the upsampler to detect bottom of image. */
138	0	max_rows = out_rows_avail - *out_row_ctr;
139	0	if (max_rows > post->strip_height)
140	0	max_rows = post->strip_height;
141	0	num_rows = 0;
142	0	(*cinfo->upsample->upsample) (cinfo,
143	0	input_buf, in_row_group_ctr, in_row_groups_avail,
144	0	post->buffer, &num_rows, max_rows);
145		/* Quantize and emit data. */
146	0	(*cinfo->cquantize->color_quantize) (cinfo,
147	0	post->buffer, output_buf + *out_row_ctr, (int) num_rows);
148	0	*out_row_ctr += num_rows;
149	0	}
150
151
152		#ifdef QUANT_2PASS_SUPPORTED
153
154		/*
155		* Process some data in the first pass of 2-pass quantization.
156		*/
157
158		METHODDEF(void)
159		post_process_prepass (j_decompress_ptr cinfo,
160		JSAMPIMAGE input_buf, JDIMENSION *in_row_group_ctr,
161		JDIMENSION in_row_groups_avail,
162		CPL_UNUSED JSAMPARRAY output_buf, JDIMENSION *out_row_ctr,
163		CPL_UNUSED JDIMENSION out_rows_avail)
164	0	{
165	0	my_post_ptr post = (my_post_ptr) cinfo->post;
166	0	JDIMENSION old_next_row, num_rows;
167
168		/* Reposition virtual buffer if at start of strip. */
169	0	if (post->next_row == 0) {
170	0	post->buffer = (*cinfo->mem->access_virt_sarray)
171	0	((j_common_ptr) cinfo, post->whole_image,
172	0	post->starting_row, post->strip_height, TRUE);
173	0	}
174
175		/* Upsample some data (up to a strip height's worth). */
176	0	old_next_row = post->next_row;
177	0	(*cinfo->upsample->upsample) (cinfo,
178	0	input_buf, in_row_group_ctr, in_row_groups_avail,
179	0	post->buffer, &post->next_row, post->strip_height);
180
181		/* Allow quantizer to scan new data. No data is emitted, */
182		/* but we advance out_row_ctr so outer loop can tell when we're done. */
183	0	if (post->next_row > old_next_row) {
184	0	num_rows = post->next_row - old_next_row;
185	0	(*cinfo->cquantize->color_quantize) (cinfo, post->buffer + old_next_row,
186	0	(JSAMPARRAY) NULL, (int) num_rows);
187	0	*out_row_ctr += num_rows;
188	0	}
189
190		/* Advance if we filled the strip. */
191	0	if (post->next_row >= post->strip_height) {
192	0	post->starting_row += post->strip_height;
193	0	post->next_row = 0;
194	0	}
195	0	}
196
197
198		/*
199		* Process some data in the second pass of 2-pass quantization.
200		*/
201
202		METHODDEF(void)
203		post_process_2pass (j_decompress_ptr cinfo,
204		CPL_UNUSED JSAMPIMAGE input_buf, CPL_UNUSED JDIMENSION *in_row_group_ctr,
205		CPL_UNUSED JDIMENSION in_row_groups_avail,
206		JSAMPARRAY output_buf, JDIMENSION *out_row_ctr,
207		JDIMENSION out_rows_avail)
208	0	{
209	0	my_post_ptr post = (my_post_ptr) cinfo->post;
210	0	JDIMENSION num_rows, max_rows;
211
212		/* Reposition virtual buffer if at start of strip. */
213	0	if (post->next_row == 0) {
214	0	post->buffer = (*cinfo->mem->access_virt_sarray)
215	0	((j_common_ptr) cinfo, post->whole_image,
216	0	post->starting_row, post->strip_height, FALSE);
217	0	}
218
219		/* Determine number of rows to emit. */
220	0	num_rows = post->strip_height - post->next_row; /* available in strip */
221	0	max_rows = out_rows_avail - out_row_ctr; / available in output area */
222	0	if (num_rows > max_rows)
223	0	num_rows = max_rows;
224		/* We have to check bottom of image here, can't depend on upsampler. */
225	0	max_rows = cinfo->output_height - post->starting_row;
226	0	if (num_rows > max_rows)
227	0	num_rows = max_rows;
228
229		/* Quantize and emit data. */
230	0	(*cinfo->cquantize->color_quantize) (cinfo,
231	0	post->buffer + post->next_row, output_buf + *out_row_ctr,
232	0	(int) num_rows);
233	0	*out_row_ctr += num_rows;
234
235		/* Advance if we filled the strip. */
236	0	post->next_row += num_rows;
237	0	if (post->next_row >= post->strip_height) {
238	0	post->starting_row += post->strip_height;
239	0	post->next_row = 0;
240	0	}
241	0	}
242
243		#endif /* QUANT_2PASS_SUPPORTED */
244
245
246		/*
247		* Initialize postprocessing controller.
248		*/
249
250		GLOBAL(void)
251		jinit_d_post_controller (j_decompress_ptr cinfo, boolean need_full_buffer)
252	0	{
253	0	my_post_ptr post;
254
255	0	post = (my_post_ptr)
256	0	(*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
257	0	SIZEOF(my_post_controller));
258	0	cinfo->post = (struct jpeg_d_post_controller *) post;
259	0	post->pub.start_pass = start_pass_dpost;
260	0	post->whole_image = NULL; /* flag for no virtual arrays */
261	0	post->buffer = NULL; /* flag for no strip buffer */
262
263		/* Create the quantization buffer, if needed */
264	0	if (cinfo->quantize_colors) {
265		/* The buffer strip height is max_v_samp_factor, which is typically
266		* an efficient number of rows for upsampling to return.
267		* (In the presence of output rescaling, we might want to be smarter?)
268		*/
269	0	post->strip_height = (JDIMENSION) cinfo->max_v_samp_factor;
270	0	if (need_full_buffer) {
271		/* Two-pass color quantization: need full-image storage. */
272		/* We round up the number of rows to a multiple of the strip height. */
273	0	#ifdef QUANT_2PASS_SUPPORTED
274	0	post->whole_image = (*cinfo->mem->request_virt_sarray)
275	0	((j_common_ptr) cinfo, JPOOL_IMAGE, FALSE,
276	0	cinfo->output_width * cinfo->out_color_components,
277	0	(JDIMENSION) jround_up((long) cinfo->output_height,
278	0	(long) post->strip_height),
279	0	post->strip_height);
280		#else
281		ERREXIT(cinfo, JERR_BAD_BUFFER_MODE);
282		#endif /* QUANT_2PASS_SUPPORTED */
283	0	} else {
284		/* One-pass color quantization: just make a strip buffer. */
285	0	post->buffer = (*cinfo->mem->alloc_sarray)
286	0	((j_common_ptr) cinfo, JPOOL_IMAGE,
287	0	cinfo->output_width * cinfo->out_color_components,
288	0	post->strip_height);
289	0	}
290	0	}
291	0	}