/src/libjpeg-turbo.main/jdpostct.c

Source (jump to first uncovered line)
/*
 * jdpostct.c
 *
 * This file was part of the Independent JPEG Group's software:
 * Copyright (C) 1994-1996, Thomas G. Lane.
 * It was modified by The libjpeg-turbo Project to include only code relevant
 * to libjpeg-turbo.
 * For conditions of distribution and use, see the accompanying README.ijg
 * 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"


/* 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(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(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(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, JSAMPARRAY output_buf,
                     JDIMENSION *out_row_ctr, 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, 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;

  /* 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: 2024-08-17 06:42

Line	Count	Source (jump to first uncovered line)
1		/*
2		* jdpostct.c
3		*
4		* This file was part of the Independent JPEG Group's software:
5		* Copyright (C) 1994-1996, Thomas G. Lane.
6		* It was modified by The libjpeg-turbo Project to include only code relevant
7		* to libjpeg-turbo.
8		* For conditions of distribution and use, see the accompanying README.ijg
9		* file.
10		*
11		* This file contains the decompression postprocessing controller.
12		* This controller manages the upsampling, color conversion, and color
13		* quantization/reduction steps; specifically, it controls the buffering
14		* between upsample/color conversion and color quantization/reduction.
15		*
16		* If no color quantization/reduction is required, then this module has no
17		* work to do, and it just hands off to the upsample/color conversion code.
18		* An integrated upsample/convert/quantize process would replace this module
19		* entirely.
20		*/
21
22		#define JPEG_INTERNALS
23		#include "jinclude.h"
24		#include "jpeglib.h"
25
26
27		/* Private buffer controller object */
28
29		typedef struct {
30		struct jpeg_d_post_controller pub; /* public fields */
31
32		/* Color quantization source buffer: this holds output data from
33		* the upsample/color conversion step to be passed to the quantizer.
34		* For two-pass color quantization, we need a full-image buffer;
35		* for one-pass operation, a strip buffer is sufficient.
36		*/
37		jvirt_sarray_ptr whole_image; /* virtual array, or NULL if one-pass */
38		JSAMPARRAY buffer; /* strip buffer, or current strip of virtual */
39		JDIMENSION strip_height; /* buffer size in rows */
40		/* for two-pass mode only: */
41		JDIMENSION starting_row; /* row # of first row in current strip */
42		JDIMENSION next_row; /* index of next row to fill/empty in strip */
43		} my_post_controller;
44
45		typedef my_post_controller *my_post_ptr;
46
47
48		/* Forward declarations */
49		METHODDEF(void) post_process_1pass(j_decompress_ptr cinfo,
50		JSAMPIMAGE input_buf,
51		JDIMENSION *in_row_group_ctr,
52		JDIMENSION in_row_groups_avail,
53		JSAMPARRAY output_buf,
54		JDIMENSION *out_row_ctr,
55		JDIMENSION out_rows_avail);
56		#ifdef QUANT_2PASS_SUPPORTED
57		METHODDEF(void) post_process_prepass(j_decompress_ptr cinfo,
58		JSAMPIMAGE input_buf,
59		JDIMENSION *in_row_group_ctr,
60		JDIMENSION in_row_groups_avail,
61		JSAMPARRAY output_buf,
62		JDIMENSION *out_row_ctr,
63		JDIMENSION out_rows_avail);
64		METHODDEF(void) post_process_2pass(j_decompress_ptr cinfo,
65		JSAMPIMAGE input_buf,
66		JDIMENSION *in_row_group_ctr,
67		JDIMENSION in_row_groups_avail,
68		JSAMPARRAY output_buf,
69		JDIMENSION *out_row_ctr,
70		JDIMENSION out_rows_avail);
71		#endif
72
73
74		/*
75		* Initialize for a processing pass.
76		*/
77
78		METHODDEF(void)
79		start_pass_dpost(j_decompress_ptr cinfo, J_BUF_MODE pass_mode)
80	7.78k	{
81	7.78k	my_post_ptr post = (my_post_ptr)cinfo->post;
82
83	7.78k	switch (pass_mode) {
84	7.78k	case JBUF_PASS_THRU:
85	7.78k	if (cinfo->quantize_colors) {
86		/* Single-pass processing with color quantization. */
87	0	post->pub.post_process_data = post_process_1pass;
88		/* We could be doing buffered-image output before starting a 2-pass
89		* color quantization; in that case, jinit_d_post_controller did not
90		* allocate a strip buffer. Use the virtual-array buffer as workspace.
91		*/
92	0	if (post->buffer == NULL) {
93	0	post->buffer = (*cinfo->mem->access_virt_sarray)
94	0	((j_common_ptr)cinfo, post->whole_image,
95	0	(JDIMENSION)0, post->strip_height, TRUE);
96	0	}
97	7.78k	} else {
98		/* For single-pass processing without color quantization,
99		* I have no work to do; just call the upsampler directly.
100		*/
101	7.78k	post->pub.post_process_data = cinfo->upsample->upsample;
102	7.78k	}
103	7.78k	break;
104	0	#ifdef QUANT_2PASS_SUPPORTED
105	0	case JBUF_SAVE_AND_PASS:
106		/* First pass of 2-pass quantization */
107	0	if (post->whole_image == NULL)
108	0	ERREXIT(cinfo, JERR_BAD_BUFFER_MODE);
109	0	post->pub.post_process_data = post_process_prepass;
110	0	break;
111	0	case JBUF_CRANK_DEST:
112		/* Second pass of 2-pass quantization */
113	0	if (post->whole_image == NULL)
114	0	ERREXIT(cinfo, JERR_BAD_BUFFER_MODE);
115	0	post->pub.post_process_data = post_process_2pass;
116	0	break;
117	0	#endif /* QUANT_2PASS_SUPPORTED */
118	0	default:
119	0	ERREXIT(cinfo, JERR_BAD_BUFFER_MODE);
120	0	break;
121	7.78k	}
122	7.78k	post->starting_row = post->next_row = 0;
123	7.78k	}
124
125
126		/*
127		* Process some data in the one-pass (strip buffer) case.
128		* This is used for color precision reduction as well as one-pass quantization.
129		*/
130
131		METHODDEF(void)
132		post_process_1pass(j_decompress_ptr cinfo, JSAMPIMAGE input_buf,
133		JDIMENSION *in_row_group_ctr,
134		JDIMENSION in_row_groups_avail, JSAMPARRAY output_buf,
135		JDIMENSION *out_row_ctr, JDIMENSION out_rows_avail)
136	0	{
137	0	my_post_ptr post = (my_post_ptr)cinfo->post;
138	0	JDIMENSION num_rows, max_rows;
139
140		/* Fill the buffer, but not more than what we can dump out in one go. */
141		/* Note we rely on the upsampler to detect bottom of image. */
142	0	max_rows = out_rows_avail - *out_row_ctr;
143	0	if (max_rows > post->strip_height)
144	0	max_rows = post->strip_height;
145	0	num_rows = 0;
146	0	(*cinfo->upsample->upsample) (cinfo, input_buf, in_row_group_ctr,
147	0	in_row_groups_avail, post->buffer, &num_rows,
148	0	max_rows);
149		/* Quantize and emit data. */
150	0	(*cinfo->cquantize->color_quantize) (cinfo, post->buffer,
151	0	output_buf + *out_row_ctr,
152	0	(int)num_rows);
153	0	*out_row_ctr += num_rows;
154	0	}
155
156
157		#ifdef QUANT_2PASS_SUPPORTED
158
159		/*
160		* Process some data in the first pass of 2-pass quantization.
161		*/
162
163		METHODDEF(void)
164		post_process_prepass(j_decompress_ptr cinfo, JSAMPIMAGE input_buf,
165		JDIMENSION *in_row_group_ctr,
166		JDIMENSION in_row_groups_avail, JSAMPARRAY output_buf,
167		JDIMENSION *out_row_ctr, JDIMENSION out_rows_avail)
168	0	{
169	0	my_post_ptr post = (my_post_ptr)cinfo->post;
170	0	JDIMENSION old_next_row, num_rows;
171
172		/* Reposition virtual buffer if at start of strip. */
173	0	if (post->next_row == 0) {
174	0	post->buffer = (*cinfo->mem->access_virt_sarray)
175	0	((j_common_ptr)cinfo, post->whole_image,
176	0	post->starting_row, post->strip_height, TRUE);
177	0	}
178
179		/* Upsample some data (up to a strip height's worth). */
180	0	old_next_row = post->next_row;
181	0	(*cinfo->upsample->upsample) (cinfo, input_buf, in_row_group_ctr,
182	0	in_row_groups_avail, post->buffer,
183	0	&post->next_row, post->strip_height);
184
185		/* Allow quantizer to scan new data. No data is emitted, */
186		/* but we advance out_row_ctr so outer loop can tell when we're done. */
187	0	if (post->next_row > old_next_row) {
188	0	num_rows = post->next_row - old_next_row;
189	0	(*cinfo->cquantize->color_quantize) (cinfo, post->buffer + old_next_row,
190	0	(JSAMPARRAY)NULL, (int)num_rows);
191	0	*out_row_ctr += num_rows;
192	0	}
193
194		/* Advance if we filled the strip. */
195	0	if (post->next_row >= post->strip_height) {
196	0	post->starting_row += post->strip_height;
197	0	post->next_row = 0;
198	0	}
199	0	}
200
201
202		/*
203		* Process some data in the second pass of 2-pass quantization.
204		*/
205
206		METHODDEF(void)
207		post_process_2pass(j_decompress_ptr cinfo, JSAMPIMAGE input_buf,
208		JDIMENSION *in_row_group_ctr,
209		JDIMENSION in_row_groups_avail, JSAMPARRAY output_buf,
210		JDIMENSION *out_row_ctr, JDIMENSION out_rows_avail)
211	0	{
212	0	my_post_ptr post = (my_post_ptr)cinfo->post;
213	0	JDIMENSION num_rows, max_rows;
214
215		/* Reposition virtual buffer if at start of strip. */
216	0	if (post->next_row == 0) {
217	0	post->buffer = (*cinfo->mem->access_virt_sarray)
218	0	((j_common_ptr)cinfo, post->whole_image,
219	0	post->starting_row, post->strip_height, FALSE);
220	0	}
221
222		/* Determine number of rows to emit. */
223	0	num_rows = post->strip_height - post->next_row; /* available in strip */
224	0	max_rows = out_rows_avail - out_row_ctr; / available in output area */
225	0	if (num_rows > max_rows)
226	0	num_rows = max_rows;
227		/* We have to check bottom of image here, can't depend on upsampler. */
228	0	max_rows = cinfo->output_height - post->starting_row;
229	0	if (num_rows > max_rows)
230	0	num_rows = max_rows;
231
232		/* Quantize and emit data. */
233	0	(*cinfo->cquantize->color_quantize) (cinfo, post->buffer + post->next_row,
234	0	output_buf + *out_row_ctr,
235	0	(int)num_rows);
236	0	*out_row_ctr += num_rows;
237
238		/* Advance if we filled the strip. */
239	0	post->next_row += num_rows;
240	0	if (post->next_row >= post->strip_height) {
241	0	post->starting_row += post->strip_height;
242	0	post->next_row = 0;
243	0	}
244	0	}
245
246		#endif /* QUANT_2PASS_SUPPORTED */
247
248
249		/*
250		* Initialize postprocessing controller.
251		*/
252
253		GLOBAL(void)
254		jinit_d_post_controller(j_decompress_ptr cinfo, boolean need_full_buffer)
255	14.5k	{
256	14.5k	my_post_ptr post;
257
258	14.5k	post = (my_post_ptr)
259	14.5k	(*cinfo->mem->alloc_small) ((j_common_ptr)cinfo, JPOOL_IMAGE,
260	14.5k	sizeof(my_post_controller));
261	14.5k	cinfo->post = (struct jpeg_d_post_controller *)post;
262	14.5k	post->pub.start_pass = start_pass_dpost;
263	14.5k	post->whole_image = NULL; /* flag for no virtual arrays */
264	14.5k	post->buffer = NULL; /* flag for no strip buffer */
265
266		/* Create the quantization buffer, if needed */
267	14.5k	if (cinfo->quantize_colors) {
268		/* The buffer strip height is max_v_samp_factor, which is typically
269		* an efficient number of rows for upsampling to return.
270		* (In the presence of output rescaling, we might want to be smarter?)
271		*/
272	0	post->strip_height = (JDIMENSION)cinfo->max_v_samp_factor;
273	0	if (need_full_buffer) {
274		/* Two-pass color quantization: need full-image storage. */
275		/* We round up the number of rows to a multiple of the strip height. */
276	0	#ifdef QUANT_2PASS_SUPPORTED
277	0	post->whole_image = (*cinfo->mem->request_virt_sarray)
278	0	((j_common_ptr)cinfo, JPOOL_IMAGE, FALSE,
279	0	cinfo->output_width * cinfo->out_color_components,
280	0	(JDIMENSION)jround_up((long)cinfo->output_height,
281	0	(long)post->strip_height),
282	0	post->strip_height);
283		#else
284		ERREXIT(cinfo, JERR_BAD_BUFFER_MODE);
285		#endif /* QUANT_2PASS_SUPPORTED */
286	0	} else {
287		/* One-pass color quantization: just make a strip buffer. */
288	0	post->buffer = (*cinfo->mem->alloc_sarray)
289	0	((j_common_ptr)cinfo, JPOOL_IMAGE,
290	0	cinfo->output_width * cinfo->out_color_components,
291	0	post->strip_height);
292	0	}
293	0	}
294	14.5k	}