/src/mozilla-central/media/libjpeg/jdtrans.c

Source (jump to first uncovered line)
/*
 * jdtrans.c
 *
 * This file was part of the Independent JPEG Group's software:
 * Copyright (C) 1995-1997, 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 library routines for transcoding decompression,
 * that is, reading raw DCT coefficient arrays from an input JPEG file.
 * The routines in jdapimin.c will also be needed by a transcoder.
 */

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


/* Forward declarations */
LOCAL(void) transdecode_master_selection (j_decompress_ptr cinfo);


/*
 * Read the coefficient arrays from a JPEG file.
 * jpeg_read_header must be completed before calling this.
 *
 * The entire image is read into a set of virtual coefficient-block arrays,
 * one per component.  The return value is a pointer to the array of
 * virtual-array descriptors.  These can be manipulated directly via the
 * JPEG memory manager, or handed off to jpeg_write_coefficients().
 * To release the memory occupied by the virtual arrays, call
 * jpeg_finish_decompress() when done with the data.
 *
 * An alternative usage is to simply obtain access to the coefficient arrays
 * during a buffered-image-mode decompression operation.  This is allowed
 * after any jpeg_finish_output() call.  The arrays can be accessed until
 * jpeg_finish_decompress() is called.  (Note that any call to the library
 * may reposition the arrays, so don't rely on access_virt_barray() results
 * to stay valid across library calls.)
 *
 * Returns NULL if suspended.  This case need be checked only if
 * a suspending data source is used.
 */

GLOBAL(jvirt_barray_ptr *)
jpeg_read_coefficients (j_decompress_ptr cinfo)
{
  if (cinfo->global_state == DSTATE_READY) {
    /* First call: initialize active modules */
    transdecode_master_selection(cinfo);
    cinfo->global_state = DSTATE_RDCOEFS;
  }
  if (cinfo->global_state == DSTATE_RDCOEFS) {
    /* Absorb whole file into the coef buffer */
    for (;;) {
      int retcode;
      /* Call progress monitor hook if present */
      if (cinfo->progress != NULL)
        (*cinfo->progress->progress_monitor) ((j_common_ptr) cinfo);
      /* Absorb some more input */
      retcode = (*cinfo->inputctl->consume_input) (cinfo);
      if (retcode == JPEG_SUSPENDED)
        return NULL;
      if (retcode == JPEG_REACHED_EOI)
        break;
      /* Advance progress counter if appropriate */
      if (cinfo->progress != NULL &&
          (retcode == JPEG_ROW_COMPLETED || retcode == JPEG_REACHED_SOS)) {
        if (++cinfo->progress->pass_counter >= cinfo->progress->pass_limit) {
          /* startup underestimated number of scans; ratchet up one scan */
          cinfo->progress->pass_limit += (long) cinfo->total_iMCU_rows;
        }
      }
    }
    /* Set state so that jpeg_finish_decompress does the right thing */
    cinfo->global_state = DSTATE_STOPPING;
  }
  /* At this point we should be in state DSTATE_STOPPING if being used
   * standalone, or in state DSTATE_BUFIMAGE if being invoked to get access
   * to the coefficients during a full buffered-image-mode decompression.
   */
  if ((cinfo->global_state == DSTATE_STOPPING ||
       cinfo->global_state == DSTATE_BUFIMAGE) && cinfo->buffered_image) {
    return cinfo->coef->coef_arrays;
  }
  /* Oops, improper usage */
  ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
  return NULL;                  /* keep compiler happy */
}


/*
 * Master selection of decompression modules for transcoding.
 * This substitutes for jdmaster.c's initialization of the full decompressor.
 */

LOCAL(void)
transdecode_master_selection (j_decompress_ptr cinfo)
{
  /* This is effectively a buffered-image operation. */
  cinfo->buffered_image = TRUE;

#if JPEG_LIB_VERSION >= 80
  /* Compute output image dimensions and related values. */
  jpeg_core_output_dimensions(cinfo);
#endif

  /* Entropy decoding: either Huffman or arithmetic coding. */
  if (cinfo->arith_code) {
#ifdef D_ARITH_CODING_SUPPORTED
    jinit_arith_decoder(cinfo);
#else
    ERREXIT(cinfo, JERR_ARITH_NOTIMPL);
#endif
  } else {
    if (cinfo->progressive_mode) {
#ifdef D_PROGRESSIVE_SUPPORTED
      jinit_phuff_decoder(cinfo);
#else
      ERREXIT(cinfo, JERR_NOT_COMPILED);
#endif
    } else
      jinit_huff_decoder(cinfo);
  }

  /* Always get a full-image coefficient buffer. */
  jinit_d_coef_controller(cinfo, TRUE);

  /* We can now tell the memory manager to allocate virtual arrays. */
  (*cinfo->mem->realize_virt_arrays) ((j_common_ptr) cinfo);

  /* Initialize input side of decompressor to consume first scan. */
  (*cinfo->inputctl->start_input_pass) (cinfo);

  /* Initialize progress monitoring. */
  if (cinfo->progress != NULL) {
    int nscans;
    /* Estimate number of scans to set pass_limit. */
    if (cinfo->progressive_mode) {
      /* Arbitrarily estimate 2 interleaved DC scans + 3 AC scans/component. */
      nscans = 2 + 3 * cinfo->num_components;
    } else if (cinfo->inputctl->has_multiple_scans) {
      /* For a nonprogressive multiscan file, estimate 1 scan per component. */
      nscans = cinfo->num_components;
    } else {
      nscans = 1;
    }
    cinfo->progress->pass_counter = 0L;
    cinfo->progress->pass_limit = (long) cinfo->total_iMCU_rows * nscans;
    cinfo->progress->completed_passes = 0;
    cinfo->progress->total_passes = 1;
  }
}

Line	Count	Source (jump to first uncovered line)
1		/*
2		* jdtrans.c
3		*
4		* This file was part of the Independent JPEG Group's software:
5		* Copyright (C) 1995-1997, 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 library routines for transcoding decompression,
12		* that is, reading raw DCT coefficient arrays from an input JPEG file.
13		* The routines in jdapimin.c will also be needed by a transcoder.
14		*/
15
16		#define JPEG_INTERNALS
17		#include "jinclude.h"
18		#include "jpeglib.h"
19
20
21		/* Forward declarations */
22		LOCAL(void) transdecode_master_selection (j_decompress_ptr cinfo);
23
24
25		/*
26		* Read the coefficient arrays from a JPEG file.
27		* jpeg_read_header must be completed before calling this.
28		*
29		* The entire image is read into a set of virtual coefficient-block arrays,
30		* one per component. The return value is a pointer to the array of
31		* virtual-array descriptors. These can be manipulated directly via the
32		* JPEG memory manager, or handed off to jpeg_write_coefficients().
33		* To release the memory occupied by the virtual arrays, call
34		* jpeg_finish_decompress() when done with the data.
35		*
36		* An alternative usage is to simply obtain access to the coefficient arrays
37		* during a buffered-image-mode decompression operation. This is allowed
38		* after any jpeg_finish_output() call. The arrays can be accessed until
39		* jpeg_finish_decompress() is called. (Note that any call to the library
40		* may reposition the arrays, so don't rely on access_virt_barray() results
41		* to stay valid across library calls.)
42		*
43		* Returns NULL if suspended. This case need be checked only if
44		* a suspending data source is used.
45		*/
46
47		GLOBAL(jvirt_barray_ptr *)
48		jpeg_read_coefficients (j_decompress_ptr cinfo)
49	0	{
50	0	if (cinfo->global_state == DSTATE_READY) {
51	0	/* First call: initialize active modules */
52	0	transdecode_master_selection(cinfo);
53	0	cinfo->global_state = DSTATE_RDCOEFS;
54	0	}
55	0	if (cinfo->global_state == DSTATE_RDCOEFS) {
56	0	/* Absorb whole file into the coef buffer */
57	0	for (;;) {
58	0	int retcode;
59	0	/* Call progress monitor hook if present */
60	0	if (cinfo->progress != NULL)
61	0	(*cinfo->progress->progress_monitor) ((j_common_ptr) cinfo);
62	0	/* Absorb some more input */
63	0	retcode = (*cinfo->inputctl->consume_input) (cinfo);
64	0	if (retcode == JPEG_SUSPENDED)
65	0	return NULL;
66	0	if (retcode == JPEG_REACHED_EOI)
67	0	break;
68	0	/* Advance progress counter if appropriate */
69	0	if (cinfo->progress != NULL &&
70	0	(retcode == JPEG_ROW_COMPLETED \|\| retcode == JPEG_REACHED_SOS)) {
71	0	if (++cinfo->progress->pass_counter >= cinfo->progress->pass_limit) {
72	0	/* startup underestimated number of scans; ratchet up one scan */
73	0	cinfo->progress->pass_limit += (long) cinfo->total_iMCU_rows;
74	0	}
75	0	}
76	0	}
77	0	/* Set state so that jpeg_finish_decompress does the right thing */
78	0	cinfo->global_state = DSTATE_STOPPING;
79	0	}
80	0	/* At this point we should be in state DSTATE_STOPPING if being used
81	0	* standalone, or in state DSTATE_BUFIMAGE if being invoked to get access
82	0	* to the coefficients during a full buffered-image-mode decompression.
83	0	*/
84	0	if ((cinfo->global_state == DSTATE_STOPPING \|\|
85	0	cinfo->global_state == DSTATE_BUFIMAGE) && cinfo->buffered_image) {
86	0	return cinfo->coef->coef_arrays;
87	0	}
88	0	/* Oops, improper usage */
89	0	ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
90	0	return NULL; /* keep compiler happy */
91	0	}
92
93
94		/*
95		* Master selection of decompression modules for transcoding.
96		* This substitutes for jdmaster.c's initialization of the full decompressor.
97		*/
98
99		LOCAL(void)
100		transdecode_master_selection (j_decompress_ptr cinfo)
101	0	{
102	0	/* This is effectively a buffered-image operation. */
103	0	cinfo->buffered_image = TRUE;
104	0
105		#if JPEG_LIB_VERSION >= 80
106		/* Compute output image dimensions and related values. */
107		jpeg_core_output_dimensions(cinfo);
108		#endif
109
110	0	/* Entropy decoding: either Huffman or arithmetic coding. */
111	0	if (cinfo->arith_code) {
112		#ifdef D_ARITH_CODING_SUPPORTED
113		jinit_arith_decoder(cinfo);
114		#else
115	0	ERREXIT(cinfo, JERR_ARITH_NOTIMPL);
116	0	#endif
117	0	} else {
118	0	if (cinfo->progressive_mode) {
119	0	#ifdef D_PROGRESSIVE_SUPPORTED
120	0	jinit_phuff_decoder(cinfo);
121		#else
122		ERREXIT(cinfo, JERR_NOT_COMPILED);
123		#endif
124		} else
125	0	jinit_huff_decoder(cinfo);
126	0	}
127	0
128	0	/* Always get a full-image coefficient buffer. */
129	0	jinit_d_coef_controller(cinfo, TRUE);
130	0
131	0	/* We can now tell the memory manager to allocate virtual arrays. */
132	0	(*cinfo->mem->realize_virt_arrays) ((j_common_ptr) cinfo);
133	0
134	0	/* Initialize input side of decompressor to consume first scan. */
135	0	(*cinfo->inputctl->start_input_pass) (cinfo);
136	0
137	0	/* Initialize progress monitoring. */
138	0	if (cinfo->progress != NULL) {
139	0	int nscans;
140	0	/* Estimate number of scans to set pass_limit. */
141	0	if (cinfo->progressive_mode) {
142	0	/* Arbitrarily estimate 2 interleaved DC scans + 3 AC scans/component. */
143	0	nscans = 2 + 3 * cinfo->num_components;
144	0	} else if (cinfo->inputctl->has_multiple_scans) {
145	0	/* For a nonprogressive multiscan file, estimate 1 scan per component. */
146	0	nscans = cinfo->num_components;
147	0	} else {
148	0	nscans = 1;
149	0	}
150	0	cinfo->progress->pass_counter = 0L;
151	0	cinfo->progress->pass_limit = (long) cinfo->total_iMCU_rows * nscans;
152	0	cinfo->progress->completed_passes = 0;
153	0	cinfo->progress->total_passes = 1;
154	0	}
155	0	}

Coverage Report

Created: 2018-09-25 14:53