diff options
Diffstat (limited to 'jcsample.c')
| -rw-r--r-- | jcsample.c | 94 |
1 files changed, 60 insertions, 34 deletions
@@ -62,6 +62,15 @@ typedef struct { /* Downsampling method pointers, one per component */ downsample1_ptr methods[MAX_COMPONENTS]; + + /* Height of an output row group for each component. */ + int rowgroup_height[MAX_COMPONENTS]; + + /* These arrays save pixel expansion factors so that int_downsample need not + * recompute them each time. They are unused for other downsampling methods. + */ + UINT8 h_expand[MAX_COMPONENTS]; + UINT8 v_expand[MAX_COMPONENTS]; } my_downsampler; typedef my_downsampler * my_downsample_ptr; @@ -123,7 +132,8 @@ sep_downsample (j_compress_ptr cinfo, for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components; ci++, compptr++) { in_ptr = input_buf[ci] + in_row_index; - out_ptr = output_buf[ci] + (out_row_group_index * compptr->v_samp_factor); + out_ptr = output_buf[ci] + + (out_row_group_index * downsample->rowgroup_height[ci]); (*downsample->methods[ci]) (cinfo, compptr, in_ptr, out_ptr); } } @@ -140,14 +150,15 @@ METHODDEF(void) int_downsample (j_compress_ptr cinfo, jpeg_component_info * compptr, JSAMPARRAY input_data, JSAMPARRAY output_data) { + my_downsample_ptr downsample = (my_downsample_ptr) cinfo->downsample; int inrow, outrow, h_expand, v_expand, numpix, numpix2, h, v; JDIMENSION outcol, outcol_h; /* outcol_h == outcol*h_expand */ - JDIMENSION output_cols = compptr->width_in_blocks * DCTSIZE; + JDIMENSION output_cols = compptr->width_in_blocks * compptr->DCT_h_scaled_size; JSAMPROW inptr, outptr; INT32 outvalue; - h_expand = cinfo->max_h_samp_factor / compptr->h_samp_factor; - v_expand = cinfo->max_v_samp_factor / compptr->v_samp_factor; + h_expand = downsample->h_expand[compptr->component_index]; + v_expand = downsample->v_expand[compptr->component_index]; numpix = h_expand * v_expand; numpix2 = numpix/2; @@ -158,8 +169,8 @@ int_downsample (j_compress_ptr cinfo, jpeg_component_info * compptr, expand_right_edge(input_data, cinfo->max_v_samp_factor, cinfo->image_width, output_cols * h_expand); - inrow = 0; - for (outrow = 0; outrow < compptr->v_samp_factor; outrow++) { + inrow = outrow = 0; + while (inrow < cinfo->max_v_samp_factor) { outptr = output_data[outrow]; for (outcol = 0, outcol_h = 0; outcol < output_cols; outcol++, outcol_h += h_expand) { @@ -173,6 +184,7 @@ int_downsample (j_compress_ptr cinfo, jpeg_component_info * compptr, *outptr++ = (JSAMPLE) ((outvalue + numpix2) / numpix); } inrow += v_expand; + outrow++; } } @@ -191,8 +203,8 @@ fullsize_downsample (j_compress_ptr cinfo, jpeg_component_info * compptr, jcopy_sample_rows(input_data, 0, output_data, 0, cinfo->max_v_samp_factor, cinfo->image_width); /* Edge-expand */ - expand_right_edge(output_data, cinfo->max_v_samp_factor, - cinfo->image_width, compptr->width_in_blocks * DCTSIZE); + expand_right_edge(output_data, cinfo->max_v_samp_factor, cinfo->image_width, + compptr->width_in_blocks * compptr->DCT_h_scaled_size); } @@ -212,9 +224,9 @@ METHODDEF(void) h2v1_downsample (j_compress_ptr cinfo, jpeg_component_info * compptr, JSAMPARRAY input_data, JSAMPARRAY output_data) { - int outrow; + int inrow; JDIMENSION outcol; - JDIMENSION output_cols = compptr->width_in_blocks * DCTSIZE; + JDIMENSION output_cols = compptr->width_in_blocks * compptr->DCT_h_scaled_size; register JSAMPROW inptr, outptr; register int bias; @@ -225,9 +237,9 @@ h2v1_downsample (j_compress_ptr cinfo, jpeg_component_info * compptr, expand_right_edge(input_data, cinfo->max_v_samp_factor, cinfo->image_width, output_cols * 2); - for (outrow = 0; outrow < compptr->v_samp_factor; outrow++) { - outptr = output_data[outrow]; - inptr = input_data[outrow]; + for (inrow = 0; inrow < cinfo->max_v_samp_factor; inrow++) { + outptr = output_data[inrow]; + inptr = input_data[inrow]; bias = 0; /* bias = 0,1,0,1,... for successive samples */ for (outcol = 0; outcol < output_cols; outcol++) { *outptr++ = (JSAMPLE) ((GETJSAMPLE(*inptr) + GETJSAMPLE(inptr[1]) @@ -251,7 +263,7 @@ h2v2_downsample (j_compress_ptr cinfo, jpeg_component_info * compptr, { int inrow, outrow; JDIMENSION outcol; - JDIMENSION output_cols = compptr->width_in_blocks * DCTSIZE; + JDIMENSION output_cols = compptr->width_in_blocks * compptr->DCT_h_scaled_size; register JSAMPROW inptr0, inptr1, outptr; register int bias; @@ -262,8 +274,8 @@ h2v2_downsample (j_compress_ptr cinfo, jpeg_component_info * compptr, expand_right_edge(input_data, cinfo->max_v_samp_factor, cinfo->image_width, output_cols * 2); - inrow = 0; - for (outrow = 0; outrow < compptr->v_samp_factor; outrow++) { + inrow = outrow = 0; + while (inrow < cinfo->max_v_samp_factor) { outptr = output_data[outrow]; inptr0 = input_data[inrow]; inptr1 = input_data[inrow+1]; @@ -276,6 +288,7 @@ h2v2_downsample (j_compress_ptr cinfo, jpeg_component_info * compptr, inptr0 += 2; inptr1 += 2; } inrow += 2; + outrow++; } } @@ -294,7 +307,7 @@ h2v2_smooth_downsample (j_compress_ptr cinfo, jpeg_component_info * compptr, { int inrow, outrow; JDIMENSION colctr; - JDIMENSION output_cols = compptr->width_in_blocks * DCTSIZE; + JDIMENSION output_cols = compptr->width_in_blocks * compptr->DCT_h_scaled_size; register JSAMPROW inptr0, inptr1, above_ptr, below_ptr, outptr; INT32 membersum, neighsum, memberscale, neighscale; @@ -321,8 +334,8 @@ h2v2_smooth_downsample (j_compress_ptr cinfo, jpeg_component_info * compptr, memberscale = 16384 - cinfo->smoothing_factor * 80; /* scaled (1-5*SF)/4 */ neighscale = cinfo->smoothing_factor * 16; /* scaled SF/4 */ - inrow = 0; - for (outrow = 0; outrow < compptr->v_samp_factor; outrow++) { + inrow = outrow = 0; + while (inrow < cinfo->max_v_samp_factor) { outptr = output_data[outrow]; inptr0 = input_data[inrow]; inptr1 = input_data[inrow+1]; @@ -378,6 +391,7 @@ h2v2_smooth_downsample (j_compress_ptr cinfo, jpeg_component_info * compptr, *outptr = (JSAMPLE) ((membersum + 32768) >> 16); inrow += 2; + outrow++; } } @@ -392,9 +406,9 @@ METHODDEF(void) fullsize_smooth_downsample (j_compress_ptr cinfo, jpeg_component_info *compptr, JSAMPARRAY input_data, JSAMPARRAY output_data) { - int outrow; + int inrow; JDIMENSION colctr; - JDIMENSION output_cols = compptr->width_in_blocks * DCTSIZE; + JDIMENSION output_cols = compptr->width_in_blocks * compptr->DCT_h_scaled_size; register JSAMPROW inptr, above_ptr, below_ptr, outptr; INT32 membersum, neighsum, memberscale, neighscale; int colsum, lastcolsum, nextcolsum; @@ -415,11 +429,11 @@ fullsize_smooth_downsample (j_compress_ptr cinfo, jpeg_component_info *compptr, memberscale = 65536L - cinfo->smoothing_factor * 512L; /* scaled 1-8*SF */ neighscale = cinfo->smoothing_factor * 64; /* scaled SF */ - for (outrow = 0; outrow < compptr->v_samp_factor; outrow++) { - outptr = output_data[outrow]; - inptr = input_data[outrow]; - above_ptr = input_data[outrow-1]; - below_ptr = input_data[outrow+1]; + for (inrow = 0; inrow < cinfo->max_v_samp_factor; inrow++) { + outptr = output_data[inrow]; + inptr = input_data[inrow]; + above_ptr = input_data[inrow-1]; + below_ptr = input_data[inrow+1]; /* Special case for first column */ colsum = GETJSAMPLE(*above_ptr++) + GETJSAMPLE(*below_ptr++) + @@ -467,6 +481,7 @@ jinit_downsampler (j_compress_ptr cinfo) int ci; jpeg_component_info * compptr; boolean smoothok = TRUE; + int h_in_group, v_in_group, h_out_group, v_out_group; downsample = (my_downsample_ptr) (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE, @@ -482,8 +497,17 @@ jinit_downsampler (j_compress_ptr cinfo) /* Verify we can handle the sampling factors, and set up method pointers */ for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components; ci++, compptr++) { - if (compptr->h_samp_factor == cinfo->max_h_samp_factor && - compptr->v_samp_factor == cinfo->max_v_samp_factor) { + /* Compute size of an "output group" for DCT scaling. This many samples + * are to be converted from max_h_samp_factor * max_v_samp_factor pixels. + */ + h_out_group = (compptr->h_samp_factor * compptr->DCT_h_scaled_size) / + cinfo->min_DCT_h_scaled_size; + v_out_group = (compptr->v_samp_factor * compptr->DCT_v_scaled_size) / + cinfo->min_DCT_v_scaled_size; + h_in_group = cinfo->max_h_samp_factor; + v_in_group = cinfo->max_v_samp_factor; + downsample->rowgroup_height[ci] = v_out_group; /* save for use later */ + if (h_in_group == h_out_group && v_in_group == v_out_group) { #ifdef INPUT_SMOOTHING_SUPPORTED if (cinfo->smoothing_factor) { downsample->methods[ci] = fullsize_smooth_downsample; @@ -491,12 +515,12 @@ jinit_downsampler (j_compress_ptr cinfo) } else #endif downsample->methods[ci] = fullsize_downsample; - } else if (compptr->h_samp_factor * 2 == cinfo->max_h_samp_factor && - compptr->v_samp_factor == cinfo->max_v_samp_factor) { + } else if (h_in_group == h_out_group * 2 && + v_in_group == v_out_group) { smoothok = FALSE; downsample->methods[ci] = h2v1_downsample; - } else if (compptr->h_samp_factor * 2 == cinfo->max_h_samp_factor && - compptr->v_samp_factor * 2 == cinfo->max_v_samp_factor) { + } else if (h_in_group == h_out_group * 2 && + v_in_group == v_out_group * 2) { #ifdef INPUT_SMOOTHING_SUPPORTED if (cinfo->smoothing_factor) { downsample->methods[ci] = h2v2_smooth_downsample; @@ -504,10 +528,12 @@ jinit_downsampler (j_compress_ptr cinfo) } else #endif downsample->methods[ci] = h2v2_downsample; - } else if ((cinfo->max_h_samp_factor % compptr->h_samp_factor) == 0 && - (cinfo->max_v_samp_factor % compptr->v_samp_factor) == 0) { + } else if ((h_in_group % h_out_group) == 0 && + (v_in_group % v_out_group) == 0) { smoothok = FALSE; downsample->methods[ci] = int_downsample; + downsample->h_expand[ci] = (UINT8) (h_in_group / h_out_group); + downsample->v_expand[ci] = (UINT8) (v_in_group / v_out_group); } else ERREXIT(cinfo, JERR_FRACT_SAMPLE_NOTIMPL); } |