jdsample.c File Reference

#include "jinclude.h"
#include "jpeglib.h"

Include dependency graph for jdsample.c:

Go to the source code of this file.

Classes
struct	my_upsampler

Macros
#define	JPEG_INTERNALS

Typedefs
typedef my_upsampler *	my_upsample_ptr

Functions
typedef	JMETHOD (void, upsample1_ptr,(j_decompress_ptr cinfo, jpeg_component_info *compptr, JSAMPARRAY input_data, JSAMPARRAY *output_data_ptr))
	start_pass_upsample (j_decompress_ptr cinfo)
	sep_upsample (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)
	fullsize_upsample (j_decompress_ptr cinfo, jpeg_component_info *compptr, JSAMPARRAY input_data, JSAMPARRAY *output_data_ptr)
	noop_upsample (j_decompress_ptr cinfo, jpeg_component_info *compptr, JSAMPARRAY input_data, JSAMPARRAY *output_data_ptr)
	int_upsample (j_decompress_ptr cinfo, jpeg_component_info *compptr, JSAMPARRAY input_data, JSAMPARRAY *output_data_ptr)
	h2v1_upsample (j_decompress_ptr cinfo, jpeg_component_info *compptr, JSAMPARRAY input_data, JSAMPARRAY *output_data_ptr)
	h2v2_upsample (j_decompress_ptr cinfo, jpeg_component_info *compptr, JSAMPARRAY input_data, JSAMPARRAY *output_data_ptr)
	jinit_upsampler (j_decompress_ptr cinfo)

Macro Definition Documentation

JPEG_INTERNALS

#define JPEG_INTERNALS

Definition at line 22 of file jdsample.c.

Typedef Documentation

my_upsample_ptr

typedef my_upsampler* my_upsample_ptr

Definition at line 62 of file jdsample.c.

Function Documentation

fullsize_upsample()

fullsize_upsample	(	j_decompress_ptr	cinfo,
		jpeg_component_info *	compptr,
		JSAMPARRAY	input_data,
		JSAMPARRAY *	output_data_ptr
	)

Definition at line 158 of file jdsample.c.

{
  *output_data_ptr = input_data;
}

Referenced by jinit_upsampler().

h2v1_upsample()

h2v1_upsample	(	j_decompress_ptr	cinfo,
		jpeg_component_info *	compptr,
		JSAMPARRAY	input_data,
		JSAMPARRAY *	output_data_ptr
	)

Definition at line 234 of file jdsample.c.

{
  JSAMPARRAY output_data = *output_data_ptr;
  register JSAMPROW inptr, outptr;
  register JSAMPLE invalue;
  JSAMPROW outend;
  int outrow;
 
  for (outrow = 0; outrow < cinfo->max_v_samp_factor; outrow++) {
    inptr = input_data[outrow];
    outptr = output_data[outrow];
    outend = outptr + cinfo->output_width;
    while (outptr < outend) {
      invalue = *inptr++;   /* don't need GETJSAMPLE() here */
      *outptr++ = invalue;
      *outptr++ = invalue;
    }
  }
}

Referenced by jinit_upsampler().

h2v2_upsample()

h2v2_upsample	(	j_decompress_ptr	cinfo,
		jpeg_component_info *	compptr,
		JSAMPARRAY	input_data,
		JSAMPARRAY *	output_data_ptr
	)

Definition at line 262 of file jdsample.c.

{
  JSAMPARRAY output_data = *output_data_ptr;
  register JSAMPROW inptr, outptr;
  register JSAMPLE invalue;
  JSAMPROW outend;
  int inrow, outrow;
 
  inrow = outrow = 0;
  while (outrow < cinfo->max_v_samp_factor) {
    inptr = input_data[inrow];
    outptr = output_data[outrow];
    outend = outptr + cinfo->output_width;
    while (outptr < outend) {
      invalue = *inptr++;   /* don't need GETJSAMPLE() here */
      *outptr++ = invalue;
      *outptr++ = invalue;
    }
    jcopy_sample_rows(output_data, outrow, output_data, outrow+1,
              1, cinfo->output_width);
    inrow++;
    outrow += 2;
  }
}

Referenced by jinit_upsampler().

int_upsample()

int_upsample	(	j_decompress_ptr	cinfo,
		jpeg_component_info *	compptr,
		JSAMPARRAY	input_data,
		JSAMPARRAY *	output_data_ptr
	)

Definition at line 190 of file jdsample.c.

{
  my_upsample_ptr upsample = (my_upsample_ptr) cinfo->upsample;
  JSAMPARRAY output_data = *output_data_ptr;
  register JSAMPROW inptr, outptr;
  register JSAMPLE invalue;
  register int h;
  JSAMPROW outend;
  int h_expand, v_expand;
  int inrow, outrow;
 
  h_expand = upsample->h_expand[compptr->component_index];
  v_expand = upsample->v_expand[compptr->component_index];
 
  inrow = outrow = 0;
  while (outrow < cinfo->max_v_samp_factor) {
    /* Generate one output row with proper horizontal expansion */
    inptr = input_data[inrow];
    outptr = output_data[outrow];
    outend = outptr + cinfo->output_width;
    while (outptr < outend) {
      invalue = *inptr++;   /* don't need GETJSAMPLE() here */
      for (h = h_expand; h > 0; h--) {
    *outptr++ = invalue;
      }
    }
    /* Generate any additional output rows by duplicating the first one */
    if (v_expand > 1) {
      jcopy_sample_rows(output_data, outrow, output_data, outrow+1,
            v_expand-1, cinfo->output_width);
    }
    inrow++;
    outrow += v_expand;
  }
}

Referenced by jinit_upsampler().

jinit_upsampler()

jinit_upsampler

(

j_decompress_ptr

cinfo

)

Definition at line 294 of file jdsample.c.

{
  my_upsample_ptr upsample;
  int ci;
  jpeg_component_info * compptr;
  int h_in_group, v_in_group, h_out_group, v_out_group;
 
  upsample = (my_upsample_ptr)
    (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
                SIZEOF(my_upsampler));
  cinfo->upsample = &upsample->pub;
  upsample->pub.start_pass = start_pass_upsample;
  upsample->pub.upsample = sep_upsample;
  upsample->pub.need_context_rows = FALSE; /* until we find out differently */
 
  if (cinfo->CCIR601_sampling)  /* this isn't supported */
    ERREXIT(cinfo, JERR_CCIR601_NOTIMPL);
 
  /* Verify we can handle the sampling factors, select per-component methods,
   * and create storage as needed.
   */
  for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
       ci++, compptr++) {
    /* Compute size of an "input group" after IDCT scaling.  This many samples
     * are to be converted to max_h_samp_factor * max_v_samp_factor pixels.
     */
    h_in_group = (compptr->h_samp_factor * compptr->DCT_h_scaled_size) /
         cinfo->min_DCT_h_scaled_size;
    v_in_group = (compptr->v_samp_factor * compptr->DCT_v_scaled_size) /
         cinfo->min_DCT_v_scaled_size;
    h_out_group = cinfo->max_h_samp_factor;
    v_out_group = cinfo->max_v_samp_factor;
    upsample->rowgroup_height[ci] = v_in_group; /* save for use later */
    if (! compptr->component_needed) {
      /* Don't bother to upsample an uninteresting component. */
      upsample->methods[ci] = noop_upsample;
      continue;     /* don't need to allocate buffer */
    }
    if (h_in_group == h_out_group && v_in_group == v_out_group) {
      /* Fullsize components can be processed without any work. */
      upsample->methods[ci] = fullsize_upsample;
      continue;     /* don't need to allocate buffer */
    }
    if (h_in_group * 2 == h_out_group && v_in_group == v_out_group) {
      /* Special case for 2h1v upsampling */
      upsample->methods[ci] = h2v1_upsample;
    } else if (h_in_group * 2 == h_out_group &&
           v_in_group * 2 == v_out_group) {
      /* Special case for 2h2v upsampling */
      upsample->methods[ci] = h2v2_upsample;
    } else if ((h_out_group % h_in_group) == 0 &&
           (v_out_group % v_in_group) == 0) {
      /* Generic integral-factors upsampling method */
      upsample->methods[ci] = int_upsample;
      upsample->h_expand[ci] = (UINT8) (h_out_group / h_in_group);
      upsample->v_expand[ci] = (UINT8) (v_out_group / v_in_group);
    } else
      ERREXIT(cinfo, JERR_FRACT_SAMPLE_NOTIMPL);
    upsample->color_buf[ci] = (*cinfo->mem->alloc_sarray)
      ((j_common_ptr) cinfo, JPOOL_IMAGE,
       (JDIMENSION) jround_up((long) cinfo->output_width,
                  (long) cinfo->max_h_samp_factor),
       (JDIMENSION) cinfo->max_v_samp_factor);
  }
}

Referenced by master_selection().

JMETHOD()

typedef JMETHOD	(	void	,
		upsample1_ptr	,
		(j_decompress_ptr cinfo, jpeg_component_info *compptr, JSAMPARRAY input_data, JSAMPARRAY *output_data_ptr)
	)

noop_upsample()

noop_upsample	(	j_decompress_ptr	cinfo,
		jpeg_component_info *	compptr,
		JSAMPARRAY	input_data,
		JSAMPARRAY *	output_data_ptr
	)

Definition at line 171 of file jdsample.c.

{
  *output_data_ptr = NULL;  /* safety check */
}

Referenced by jinit_upsampler().

sep_upsample()

sep_upsample	(	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
	)

Definition at line 90 of file jdsample.c.

{
  my_upsample_ptr upsample = (my_upsample_ptr) cinfo->upsample;
  int ci;
  jpeg_component_info * compptr;
  JDIMENSION num_rows;
 
  /* Fill the conversion buffer, if it's empty */
  if (upsample->next_row_out >= cinfo->max_v_samp_factor) {
    for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
     ci++, compptr++) {
      /* Invoke per-component upsample method.  Notice we pass a POINTER
       * to color_buf[ci], so that fullsize_upsample can change it.
       */
      (*upsample->methods[ci]) (cinfo, compptr,
    input_buf[ci] + (*in_row_group_ctr * upsample->rowgroup_height[ci]),
    upsample->color_buf + ci);
    }
    upsample->next_row_out = 0;
  }
 
  /* Color-convert and emit rows */
 
  /* How many we have in the buffer: */
  num_rows = (JDIMENSION) (cinfo->max_v_samp_factor - upsample->next_row_out);
  /* Not more than the distance to the end of the image.  Need this test
   * in case the image height is not a multiple of max_v_samp_factor:
   */
  if (num_rows > upsample->rows_to_go) 
    num_rows = upsample->rows_to_go;
  /* And not more than what the client can accept: */
  out_rows_avail -= *out_row_ctr;
  if (num_rows > out_rows_avail)
    num_rows = out_rows_avail;
 
  (*cinfo->cconvert->color_convert) (cinfo, upsample->color_buf,
                     (JDIMENSION) upsample->next_row_out,
                     output_buf + *out_row_ctr,
                     (int) num_rows);
 
  /* Adjust counts */
  *out_row_ctr += num_rows;
  upsample->rows_to_go -= num_rows;
  upsample->next_row_out += num_rows;
  /* When the buffer is emptied, declare this input row group consumed */
  if (upsample->next_row_out >= cinfo->max_v_samp_factor)
    (*in_row_group_ctr)++;
}

Referenced by jinit_upsampler().

start_pass_upsample()

start_pass_upsample

(

j_decompress_ptr

cinfo

)

Definition at line 70 of file jdsample.c.

{
  my_upsample_ptr upsample = (my_upsample_ptr) cinfo->upsample;
 
  /* Mark the conversion buffer empty */
  upsample->next_row_out = cinfo->max_v_samp_factor;
  /* Initialize total-height counter for detecting bottom of image */
  upsample->rows_to_go = cinfo->output_height;
}

Referenced by jinit_upsampler().