diff options
Diffstat (limited to 'jpeg/jdsample.c')
| -rw-r--r-- | jpeg/jdsample.c | 75 |
1 files changed, 29 insertions, 46 deletions
diff --git a/jpeg/jdsample.c b/jpeg/jdsample.c index fd9907e2..15afeafe 100644 --- a/jpeg/jdsample.c +++ b/jpeg/jdsample.c @@ -2,7 +2,7 @@ * jdsample.c * * Copyright (C) 1991-1996, Thomas G. Lane. - * Modified 2002-2015 by Guido Vollbeding. + * Modified 2002-2020 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. * @@ -27,7 +27,7 @@ /* 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)); + JSAMPARRAY input_data, JSAMPIMAGE output_data_ptr)); /* Private subobject */ @@ -102,6 +102,9 @@ sep_upsample (j_decompress_ptr cinfo, if (upsample->next_row_out >= cinfo->max_v_samp_factor) { for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components; ci++, compptr++) { + /* Don't bother to upsample an uninteresting component. */ + if (! compptr->component_needed) + continue; /* Invoke per-component upsample method. Notice we pass a POINTER * to color_buf[ci], so that fullsize_upsample can change it. */ @@ -156,26 +159,13 @@ sep_upsample (j_decompress_ptr cinfo, METHODDEF(void) fullsize_upsample (j_decompress_ptr cinfo, jpeg_component_info * compptr, - JSAMPARRAY input_data, JSAMPARRAY * output_data_ptr) + JSAMPARRAY input_data, JSAMPIMAGE 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 @@ -188,25 +178,25 @@ noop_upsample (j_decompress_ptr cinfo, jpeg_component_info * compptr, METHODDEF(void) int_upsample (j_decompress_ptr cinfo, jpeg_component_info * compptr, - JSAMPARRAY input_data, JSAMPARRAY * output_data_ptr) + JSAMPARRAY input_data, JSAMPIMAGE output_data_ptr) { my_upsample_ptr upsample = (my_upsample_ptr) cinfo->upsample; - JSAMPARRAY output_data = *output_data_ptr; + JSAMPARRAY output_data, output_end; 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) { + output_data = *output_data_ptr; + output_end = output_data + cinfo->max_v_samp_factor; + for (; output_data < output_end; output_data += v_expand) { /* Generate one output row with proper horizontal expansion */ - inptr = input_data[inrow]; - outptr = output_data[outrow]; + inptr = *input_data++; + outptr = *output_data; outend = outptr + cinfo->output_width; while (outptr < outend) { invalue = *inptr++; /* don't need GETJSAMPLE() here */ @@ -216,11 +206,9 @@ int_upsample (j_decompress_ptr cinfo, jpeg_component_info * compptr, } /* 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); + jcopy_sample_rows(output_data, output_data + 1, + v_expand - 1, cinfo->output_width); } - inrow++; - outrow += v_expand; } } @@ -232,7 +220,7 @@ int_upsample (j_decompress_ptr cinfo, jpeg_component_info * compptr, METHODDEF(void) h2v1_upsample (j_decompress_ptr cinfo, jpeg_component_info * compptr, - JSAMPARRAY input_data, JSAMPARRAY * output_data_ptr) + JSAMPARRAY input_data, JSAMPIMAGE output_data_ptr) { JSAMPARRAY output_data = *output_data_ptr; register JSAMPROW inptr, outptr; @@ -260,28 +248,26 @@ h2v1_upsample (j_decompress_ptr cinfo, jpeg_component_info * compptr, METHODDEF(void) h2v2_upsample (j_decompress_ptr cinfo, jpeg_component_info * compptr, - JSAMPARRAY input_data, JSAMPARRAY * output_data_ptr) + JSAMPARRAY input_data, JSAMPIMAGE output_data_ptr) { - JSAMPARRAY output_data = *output_data_ptr; + JSAMPARRAY output_data, output_end; 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]; + output_data = *output_data_ptr; + output_end = output_data + cinfo->max_v_samp_factor; + for (; output_data < output_end; output_data += 2) { + inptr = *input_data++; + outptr = *output_data; 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, + jcopy_sample_rows(output_data, output_data + 1, 1, cinfo->output_width); - inrow++; - outrow += 2; } } @@ -298,9 +284,8 @@ jinit_upsampler (j_decompress_ptr cinfo) 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)); + 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; @@ -314,6 +299,9 @@ jinit_upsampler (j_decompress_ptr cinfo) */ for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components; ci++, compptr++) { + /* Don't bother to upsample an uninteresting component. */ + if (! compptr->component_needed) + continue; /* 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. */ @@ -324,11 +312,6 @@ jinit_upsampler (j_decompress_ptr cinfo) 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; |