diff options
Diffstat (limited to 'plugins/AdvaImg/src/LibJPEG/jdsample.c')
-rw-r--r-- | plugins/AdvaImg/src/LibJPEG/jdsample.c | 722 |
1 files changed, 361 insertions, 361 deletions
diff --git a/plugins/AdvaImg/src/LibJPEG/jdsample.c b/plugins/AdvaImg/src/LibJPEG/jdsample.c index 7bc8885b02..94f9599f04 100644 --- a/plugins/AdvaImg/src/LibJPEG/jdsample.c +++ b/plugins/AdvaImg/src/LibJPEG/jdsample.c @@ -1,361 +1,361 @@ -/* - * jdsample.c - * - * Copyright (C) 1991-1996, Thomas G. Lane. - * Modified 2002-2008 by Guido Vollbeding. - * 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 upsampling routines. - * - * Upsampling input data is counted in "row groups". A row group - * is defined to be (v_samp_factor * DCT_v_scaled_size / min_DCT_v_scaled_size) - * sample rows of each component. Upsampling will normally produce - * max_v_samp_factor pixel rows from each row group (but this could vary - * if the upsampler is applying a scale factor of its own). - * - * An excellent reference for image resampling is - * Digital Image Warping, George Wolberg, 1990. - * Pub. by IEEE Computer Society Press, Los Alamitos, CA. ISBN 0-8186-8944-7. - */ - -#define JPEG_INTERNALS -#include "jinclude.h" -#include "jpeglib.h" - - -/* Pointer to routine to upsample a single component */ -typedef JMETHOD(void, upsample1_ptr, - (j_decompress_ptr cinfo, jpeg_component_info * compptr, - JSAMPARRAY input_data, JSAMPARRAY * output_data_ptr)); - -/* Private subobject */ - -typedef struct { - struct jpeg_upsampler pub; /* public fields */ - - /* Color conversion buffer. When using separate upsampling and color - * conversion steps, this buffer holds one upsampled row group until it - * has been color converted and output. - * Note: we do not allocate any storage for component(s) which are full-size, - * ie do not need rescaling. The corresponding entry of color_buf[] is - * simply set to point to the input data array, thereby avoiding copying. - */ - JSAMPARRAY color_buf[MAX_COMPONENTS]; - - /* Per-component upsampling method pointers */ - upsample1_ptr methods[MAX_COMPONENTS]; - - int next_row_out; /* counts rows emitted from color_buf */ - JDIMENSION rows_to_go; /* counts rows remaining in image */ - - /* Height of an input row group for each component. */ - int rowgroup_height[MAX_COMPONENTS]; - - /* These arrays save pixel expansion factors so that int_expand need not - * recompute them each time. They are unused for other upsampling methods. - */ - UINT8 h_expand[MAX_COMPONENTS]; - UINT8 v_expand[MAX_COMPONENTS]; -} my_upsampler; - -typedef my_upsampler * my_upsample_ptr; - - -/* - * Initialize for an upsampling pass. - */ - -METHODDEF(void) -start_pass_upsample (j_decompress_ptr cinfo) -{ - 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; -} - - -/* - * Control routine to do upsampling (and color conversion). - * - * In this version we upsample each component independently. - * We upsample one row group into the conversion buffer, then apply - * color conversion a row at a time. - */ - -METHODDEF(void) -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) -{ - 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)++; -} - - -/* - * These are the routines invoked by sep_upsample to upsample pixel values - * of a single component. One row group is processed per call. - */ - - -/* - * For full-size components, we just make color_buf[ci] point at the - * input buffer, and thus avoid copying any data. Note that this is - * safe only because sep_upsample doesn't declare the input row group - * "consumed" until we are done color converting and emitting it. - */ - -METHODDEF(void) -fullsize_upsample (j_decompress_ptr cinfo, jpeg_component_info * compptr, - JSAMPARRAY input_data, JSAMPARRAY * output_data_ptr) -{ - *output_data_ptr = input_data; -} - - -/* - * This is a no-op version used for "uninteresting" components. - * These components will not be referenced by color conversion. - */ - -METHODDEF(void) -noop_upsample (j_decompress_ptr cinfo, jpeg_component_info * compptr, - JSAMPARRAY input_data, JSAMPARRAY * output_data_ptr) -{ - *output_data_ptr = NULL; /* safety check */ -} - - -/* - * This version handles any integral sampling ratios. - * This is not used for typical JPEG files, so it need not be fast. - * Nor, for that matter, is it particularly accurate: the algorithm is - * simple replication of the input pixel onto the corresponding output - * pixels. The hi-falutin sampling literature refers to this as a - * "box filter". A box filter tends to introduce visible artifacts, - * so if you are actually going to use 3:1 or 4:1 sampling ratios - * you would be well advised to improve this code. - */ - -METHODDEF(void) -int_upsample (j_decompress_ptr cinfo, jpeg_component_info * compptr, - JSAMPARRAY input_data, JSAMPARRAY * output_data_ptr) -{ - 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; - } -} - - -/* - * Fast processing for the common case of 2:1 horizontal and 1:1 vertical. - * It's still a box filter. - */ - -METHODDEF(void) -h2v1_upsample (j_decompress_ptr cinfo, jpeg_component_info * compptr, - JSAMPARRAY input_data, JSAMPARRAY * output_data_ptr) -{ - 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; - } - } -} - - -/* - * Fast processing for the common case of 2:1 horizontal and 2:1 vertical. - * It's still a box filter. - */ - -METHODDEF(void) -h2v2_upsample (j_decompress_ptr cinfo, jpeg_component_info * compptr, - JSAMPARRAY input_data, JSAMPARRAY * output_data_ptr) -{ - 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; - } -} - - -/* - * Module initialization routine for upsampling. - */ - -GLOBAL(void) -jinit_upsampler (j_decompress_ptr cinfo) -{ - my_upsample_ptr upsample; - int ci; - jpeg_component_info * compptr; - boolean need_buffer; - 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 = (struct jpeg_upsampler *) upsample; - 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 */ - need_buffer = TRUE; - if (! compptr->component_needed) { - /* Don't bother to upsample an uninteresting component. */ - upsample->methods[ci] = noop_upsample; - need_buffer = FALSE; - } else 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; - need_buffer = FALSE; - } else 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); - if (need_buffer) { - 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); - } - } -} +/*
+ * jdsample.c
+ *
+ * Copyright (C) 1991-1996, Thomas G. Lane.
+ * Modified 2002-2008 by Guido Vollbeding.
+ * 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 upsampling routines.
+ *
+ * Upsampling input data is counted in "row groups". A row group
+ * is defined to be (v_samp_factor * DCT_v_scaled_size / min_DCT_v_scaled_size)
+ * sample rows of each component. Upsampling will normally produce
+ * max_v_samp_factor pixel rows from each row group (but this could vary
+ * if the upsampler is applying a scale factor of its own).
+ *
+ * An excellent reference for image resampling is
+ * Digital Image Warping, George Wolberg, 1990.
+ * Pub. by IEEE Computer Society Press, Los Alamitos, CA. ISBN 0-8186-8944-7.
+ */
+
+#define JPEG_INTERNALS
+#include "jinclude.h"
+#include "jpeglib.h"
+
+
+/* Pointer to routine to upsample a single component */
+typedef JMETHOD(void, upsample1_ptr,
+ (j_decompress_ptr cinfo, jpeg_component_info * compptr,
+ JSAMPARRAY input_data, JSAMPARRAY * output_data_ptr));
+
+/* Private subobject */
+
+typedef struct {
+ struct jpeg_upsampler pub; /* public fields */
+
+ /* Color conversion buffer. When using separate upsampling and color
+ * conversion steps, this buffer holds one upsampled row group until it
+ * has been color converted and output.
+ * Note: we do not allocate any storage for component(s) which are full-size,
+ * ie do not need rescaling. The corresponding entry of color_buf[] is
+ * simply set to point to the input data array, thereby avoiding copying.
+ */
+ JSAMPARRAY color_buf[MAX_COMPONENTS];
+
+ /* Per-component upsampling method pointers */
+ upsample1_ptr methods[MAX_COMPONENTS];
+
+ int next_row_out; /* counts rows emitted from color_buf */
+ JDIMENSION rows_to_go; /* counts rows remaining in image */
+
+ /* Height of an input row group for each component. */
+ int rowgroup_height[MAX_COMPONENTS];
+
+ /* These arrays save pixel expansion factors so that int_expand need not
+ * recompute them each time. They are unused for other upsampling methods.
+ */
+ UINT8 h_expand[MAX_COMPONENTS];
+ UINT8 v_expand[MAX_COMPONENTS];
+} my_upsampler;
+
+typedef my_upsampler * my_upsample_ptr;
+
+
+/*
+ * Initialize for an upsampling pass.
+ */
+
+METHODDEF(void)
+start_pass_upsample (j_decompress_ptr cinfo)
+{
+ 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;
+}
+
+
+/*
+ * Control routine to do upsampling (and color conversion).
+ *
+ * In this version we upsample each component independently.
+ * We upsample one row group into the conversion buffer, then apply
+ * color conversion a row at a time.
+ */
+
+METHODDEF(void)
+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)
+{
+ 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)++;
+}
+
+
+/*
+ * These are the routines invoked by sep_upsample to upsample pixel values
+ * of a single component. One row group is processed per call.
+ */
+
+
+/*
+ * For full-size components, we just make color_buf[ci] point at the
+ * input buffer, and thus avoid copying any data. Note that this is
+ * safe only because sep_upsample doesn't declare the input row group
+ * "consumed" until we are done color converting and emitting it.
+ */
+
+METHODDEF(void)
+fullsize_upsample (j_decompress_ptr cinfo, jpeg_component_info * compptr,
+ JSAMPARRAY input_data, JSAMPARRAY * output_data_ptr)
+{
+ *output_data_ptr = input_data;
+}
+
+
+/*
+ * This is a no-op version used for "uninteresting" components.
+ * These components will not be referenced by color conversion.
+ */
+
+METHODDEF(void)
+noop_upsample (j_decompress_ptr cinfo, jpeg_component_info * compptr,
+ JSAMPARRAY input_data, JSAMPARRAY * output_data_ptr)
+{
+ *output_data_ptr = NULL; /* safety check */
+}
+
+
+/*
+ * This version handles any integral sampling ratios.
+ * This is not used for typical JPEG files, so it need not be fast.
+ * Nor, for that matter, is it particularly accurate: the algorithm is
+ * simple replication of the input pixel onto the corresponding output
+ * pixels. The hi-falutin sampling literature refers to this as a
+ * "box filter". A box filter tends to introduce visible artifacts,
+ * so if you are actually going to use 3:1 or 4:1 sampling ratios
+ * you would be well advised to improve this code.
+ */
+
+METHODDEF(void)
+int_upsample (j_decompress_ptr cinfo, jpeg_component_info * compptr,
+ JSAMPARRAY input_data, JSAMPARRAY * output_data_ptr)
+{
+ 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;
+ }
+}
+
+
+/*
+ * Fast processing for the common case of 2:1 horizontal and 1:1 vertical.
+ * It's still a box filter.
+ */
+
+METHODDEF(void)
+h2v1_upsample (j_decompress_ptr cinfo, jpeg_component_info * compptr,
+ JSAMPARRAY input_data, JSAMPARRAY * output_data_ptr)
+{
+ 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;
+ }
+ }
+}
+
+
+/*
+ * Fast processing for the common case of 2:1 horizontal and 2:1 vertical.
+ * It's still a box filter.
+ */
+
+METHODDEF(void)
+h2v2_upsample (j_decompress_ptr cinfo, jpeg_component_info * compptr,
+ JSAMPARRAY input_data, JSAMPARRAY * output_data_ptr)
+{
+ 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;
+ }
+}
+
+
+/*
+ * Module initialization routine for upsampling.
+ */
+
+GLOBAL(void)
+jinit_upsampler (j_decompress_ptr cinfo)
+{
+ my_upsample_ptr upsample;
+ int ci;
+ jpeg_component_info * compptr;
+ boolean need_buffer;
+ 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 = (struct jpeg_upsampler *) upsample;
+ 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 */
+ need_buffer = TRUE;
+ if (! compptr->component_needed) {
+ /* Don't bother to upsample an uninteresting component. */
+ upsample->methods[ci] = noop_upsample;
+ need_buffer = FALSE;
+ } else 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;
+ need_buffer = FALSE;
+ } else 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);
+ if (need_buffer) {
+ 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);
+ }
+ }
+}
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