pre_process_data (j_compress_ptr cinfo,
JSAMPARRAY input_buf, JDIMENSION *in_row_ctr,
JDIMENSION in_rows_avail,
JSAMPIMAGE output_buf, JDIMENSION *out_row_group_ctr,
JDIMENSION out_row_groups_avail)
{
my_prep_ptr prep = (my_prep_ptr) cinfo->prep;
int numrows, ci;
JDIMENSION inrows;
jpeg_component_info * compptr;
while (*in_row_ctr < in_rows_avail &&
*out_row_group_ctr < out_row_groups_avail) {
/* Do color conversion to fill the conversion buffer. */
inrows = in_rows_avail - *in_row_ctr;
numrows = cinfo->max_v_samp_factor - prep->next_buf_row;
numrows = (int) MIN((JDIMENSION) numrows, inrows);
(*cinfo->cconvert->color_convert) (cinfo, input_buf + *in_row_ctr,
prep->color_buf,
(JDIMENSION) prep->next_buf_row,
numrows);
*in_row_ctr += numrows;
prep->next_buf_row += numrows;
prep->rows_to_go -= numrows;
/* If at bottom of image, pad to fill the conversion buffer. */
if (prep->rows_to_go == 0 &&
prep->next_buf_row < cinfo->max_v_samp_factor) {
for (ci = 0; ci < cinfo->num_components; ci++) {
expand_bottom_edge(prep->color_buf[ci], cinfo->image_width,
prep->next_buf_row, cinfo->max_v_samp_factor);
}
prep->next_buf_row = cinfo->max_v_samp_factor;
}
/* If we've filled the conversion buffer, empty it. */
if (prep->next_buf_row == cinfo->max_v_samp_factor) {
(*cinfo->downsample->downsample) (cinfo,
prep->color_buf, (JDIMENSION) 0,
output_buf, *out_row_group_ctr);
prep->next_buf_row = 0;
(*out_row_group_ctr)++;
}
/* If at bottom of image, pad the output to a full iMCU height.
* Note we assume the caller is providing a one-iMCU-height output buffer!
*/
if (prep->rows_to_go == 0 &&
*out_row_group_ctr < out_row_groups_avail) {
for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
ci++, compptr++) {
numrows = (compptr->v_samp_factor * compptr->DCT_v_scaled_size) /
cinfo->min_DCT_v_scaled_size;
expand_bottom_edge(output_buf[ci],
compptr->width_in_blocks * compptr->DCT_h_scaled_size,
(int) (*out_row_group_ctr * numrows),
(int) (out_row_groups_avail * numrows));
}
*out_row_group_ctr = out_row_groups_avail;
break; /* can exit outer loop without test */
}
}
}
pre_process_context (j_compress_ptr cinfo,
JSAMPARRAY input_buf, JDIMENSION *in_row_ctr,
JDIMENSION in_rows_avail,
JSAMPIMAGE output_buf, JDIMENSION *out_row_group_ctr,
JDIMENSION out_row_groups_avail)
{
my_prep_ptr prep = (my_prep_ptr) cinfo->prep;
int numrows, ci;
int buf_height = cinfo->max_v_samp_factor * 3;
JDIMENSION inrows;
while (*out_row_group_ctr < out_row_groups_avail) {
if (*in_row_ctr < in_rows_avail) {
/* Do color conversion to fill the conversion buffer. */
inrows = in_rows_avail - *in_row_ctr;
numrows = prep->next_buf_stop - prep->next_buf_row;
numrows = (int) MIN((JDIMENSION) numrows, inrows);
(*cinfo->cconvert->color_convert) (cinfo, input_buf + *in_row_ctr,
prep->color_buf,
(JDIMENSION) prep->next_buf_row,
numrows);
/* Pad at top of image, if first time through */
if (prep->rows_to_go == cinfo->image_height) {
for (ci = 0; ci < cinfo->num_components; ci++) {
int row;
for (row = 1; row <= cinfo->max_v_samp_factor; row++) {
jcopy_sample_rows(prep->color_buf[ci], 0,
prep->color_buf[ci], -row,
1, cinfo->image_width);
}
}
}
*in_row_ctr += numrows;
prep->next_buf_row += numrows;
prep->rows_to_go -= numrows;
} else {
/* Return for more data, unless we are at the bottom of the image. */
if (prep->rows_to_go != 0)
break;
/* When at bottom of image, pad to fill the conversion buffer. */
if (prep->next_buf_row < prep->next_buf_stop) {
for (ci = 0; ci < cinfo->num_components; ci++) {
expand_bottom_edge(prep->color_buf[ci], cinfo->image_width,
prep->next_buf_row, prep->next_buf_stop);
}
prep->next_buf_row = prep->next_buf_stop;
}
}
/* If we've gotten enough data, downsample a row group. */
if (prep->next_buf_row == prep->next_buf_stop) {
(*cinfo->downsample->downsample) (cinfo,
prep->color_buf,
(JDIMENSION) prep->this_row_group,
output_buf, *out_row_group_ctr);
(*out_row_group_ctr)++;
/* Advance pointers with wraparound as necessary. */
prep->this_row_group += cinfo->max_v_samp_factor;
if (prep->this_row_group >= buf_height)
prep->this_row_group = 0;
if (prep->next_buf_row >= buf_height)
prep->next_buf_row = 0;
prep->next_buf_stop = prep->next_buf_row + cinfo->max_v_samp_factor;
}
}
}
METHODDEF void
pre_process_context( j_compress_ptr cinfo,
JSAMPARRAY input_buf, JDIMENSION * in_row_ctr,
JDIMENSION in_rows_avail,
JSAMPIMAGE output_buf, JDIMENSION * out_row_group_ctr,
JDIMENSION out_row_groups_avail ) {
my_prep_ptr prep = (my_prep_ptr) cinfo->prep;
int numrows, ci;
int buf_height = cinfo->max_v_samp_factor * 3;
JDIMENSION inrows;
jpeg_component_info * compptr;
while ( *out_row_group_ctr < out_row_groups_avail ) {
if ( *in_row_ctr < in_rows_avail ) {
/* Do color conversion to fill the conversion buffer. */
inrows = in_rows_avail - *in_row_ctr;
numrows = prep->next_buf_stop - prep->next_buf_row;
numrows = (int) MIN( (JDIMENSION) numrows, inrows );
( *cinfo->cconvert->color_convert )( cinfo, input_buf + *in_row_ctr,
prep->color_buf,
(JDIMENSION) prep->next_buf_row,
numrows );
/* Pad at top of image, if first time through */
if ( prep->rows_to_go == cinfo->image_height ) {
for ( ci = 0; ci < cinfo->num_components; ci++ ) {
int row;
for ( row = 1; row <= cinfo->max_v_samp_factor; row++ ) {
jcopy_sample_rows( prep->color_buf[ci], 0,
prep->color_buf[ci], -row,
1, cinfo->image_width );
}
}
}
*in_row_ctr += numrows;
prep->next_buf_row += numrows;
prep->rows_to_go -= numrows;
} else {
/* Return for more data, unless we are at the bottom of the image. */
if ( prep->rows_to_go != 0 ) {
break;
}
}
/* If at bottom of image, pad to fill the conversion buffer. */
if ( ( prep->rows_to_go == 0 ) &&
( prep->next_buf_row < prep->next_buf_stop ) ) {
for ( ci = 0; ci < cinfo->num_components; ci++ ) {
expand_bottom_edge( prep->color_buf[ci], cinfo->image_width,
prep->next_buf_row, prep->next_buf_stop );
}
prep->next_buf_row = prep->next_buf_stop;
}
/* If we've gotten enough data, downsample a row group. */
if ( prep->next_buf_row == prep->next_buf_stop ) {
( *cinfo->downsample->downsample )( cinfo,
prep->color_buf,
(JDIMENSION) prep->this_row_group,
output_buf, *out_row_group_ctr );
( *out_row_group_ctr )++;
/* Advance pointers with wraparound as necessary. */
prep->this_row_group += cinfo->max_v_samp_factor;
if ( prep->this_row_group >= buf_height ) {
prep->this_row_group = 0;
}
if ( prep->next_buf_row >= buf_height ) {
prep->next_buf_row = 0;
}
prep->next_buf_stop = prep->next_buf_row + cinfo->max_v_samp_factor;
}
/* If at bottom of image, pad the output to a full iMCU height.
* Note we assume the caller is providing a one-iMCU-height output buffer!
*/
if ( ( prep->rows_to_go == 0 ) &&
( *out_row_group_ctr < out_row_groups_avail ) ) {
for ( ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
ci++, compptr++ ) {
expand_bottom_edge( output_buf[ci],
compptr->width_in_blocks * DCTSIZE,
(int) ( *out_row_group_ctr * compptr->v_samp_factor ),
(int) ( out_row_groups_avail * compptr->v_samp_factor ) );
}
*out_row_group_ctr = out_row_groups_avail;
break; /* can exit outer loop without test */
}
}
}
