/* * jdmerge.c * * This file was part of the Independent JPEG Group's software: * Copyright (C) 1994-1996, Thomas G. Lane. * libjpeg-turbo Modifications: * Copyright 2009 Pierre Ossman <[email protected]> for Cendio AB * Copyright (C) 2009, 2011, 2014-2015, 2020, D. R. Commander. * Copyright (C) 2013, Linaro Limited. * For conditions of distribution and use, see the accompanying README.ijg * file. * * This file contains code for merged upsampling/color conversion. * * This file combines functions from jdsample.c and jdcolor.c; * read those files first to understand what's going on. * * When the chroma components are to be upsampled by simple replication * (ie, box filtering), we can save some work in color conversion by * calculating all the output pixels corresponding to a pair of chroma * samples at one time. In the conversion equations * R = Y + K1 * Cr * G = Y + K2 * Cb + K3 * Cr * B = Y + K4 * Cb * only the Y term varies among the group of pixels corresponding to a pair * of chroma samples, so the rest of the terms can be calculated just once. * At typical sampling ratios, this eliminates half or three-quarters of the * multiplications needed for color conversion. * * This file currently provides implementations for the following cases: * YCbCr => RGB color conversion only. * Sampling ratios of 2h1v or 2h2v. * No scaling needed at upsample time. * Corner-aligned (non-CCIR601) sampling alignment. * Other special cases could be added, but in most applications these are * the only common cases. (For uncommon cases we fall back on the more * general code in jdsample.c and jdcolor.c.) */ #define JPEG_INTERNALS #include "jinclude.h" #include "jpeglib.h" #include "jdmerge.h" #include "jsimd.h" #ifdef UPSAMPLE_MERGING_SUPPORTED #define SCALEBITS … #define ONE_HALF … #define FIX(x) … /* Include inline routines for colorspace extensions */ #include "jdmrgext.c" #undef RGB_RED #undef RGB_GREEN #undef RGB_BLUE #undef RGB_PIXELSIZE #define RGB_RED … #define RGB_GREEN … #define RGB_BLUE … #define RGB_PIXELSIZE … #define h2v1_merged_upsample_internal … #define h2v2_merged_upsample_internal … #include "jdmrgext.c" #undef RGB_RED #undef RGB_GREEN #undef RGB_BLUE #undef RGB_PIXELSIZE #undef h2v1_merged_upsample_internal #undef h2v2_merged_upsample_internal #define RGB_RED … #define RGB_GREEN … #define RGB_BLUE … #define RGB_ALPHA … #define RGB_PIXELSIZE … #define h2v1_merged_upsample_internal … #define h2v2_merged_upsample_internal … #include "jdmrgext.c" #undef RGB_RED #undef RGB_GREEN #undef RGB_BLUE #undef RGB_ALPHA #undef RGB_PIXELSIZE #undef h2v1_merged_upsample_internal #undef h2v2_merged_upsample_internal #define RGB_RED … #define RGB_GREEN … #define RGB_BLUE … #define RGB_PIXELSIZE … #define h2v1_merged_upsample_internal … #define h2v2_merged_upsample_internal … #include "jdmrgext.c" #undef RGB_RED #undef RGB_GREEN #undef RGB_BLUE #undef RGB_PIXELSIZE #undef h2v1_merged_upsample_internal #undef h2v2_merged_upsample_internal #define RGB_RED … #define RGB_GREEN … #define RGB_BLUE … #define RGB_ALPHA … #define RGB_PIXELSIZE … #define h2v1_merged_upsample_internal … #define h2v2_merged_upsample_internal … #include "jdmrgext.c" #undef RGB_RED #undef RGB_GREEN #undef RGB_BLUE #undef RGB_ALPHA #undef RGB_PIXELSIZE #undef h2v1_merged_upsample_internal #undef h2v2_merged_upsample_internal #define RGB_RED … #define RGB_GREEN … #define RGB_BLUE … #define RGB_ALPHA … #define RGB_PIXELSIZE … #define h2v1_merged_upsample_internal … #define h2v2_merged_upsample_internal … #include "jdmrgext.c" #undef RGB_RED #undef RGB_GREEN #undef RGB_BLUE #undef RGB_ALPHA #undef RGB_PIXELSIZE #undef h2v1_merged_upsample_internal #undef h2v2_merged_upsample_internal #define RGB_RED … #define RGB_GREEN … #define RGB_BLUE … #define RGB_ALPHA … #define RGB_PIXELSIZE … #define h2v1_merged_upsample_internal … #define h2v2_merged_upsample_internal … #include "jdmrgext.c" #undef RGB_RED #undef RGB_GREEN #undef RGB_BLUE #undef RGB_ALPHA #undef RGB_PIXELSIZE #undef h2v1_merged_upsample_internal #undef h2v2_merged_upsample_internal /* * Initialize tables for YCC->RGB colorspace conversion. * This is taken directly from jdcolor.c; see that file for more info. */ LOCAL(void) build_ycc_rgb_table(j_decompress_ptr cinfo) { … } /* * Initialize for an upsampling pass. */ METHODDEF(void) start_pass_merged_upsample(j_decompress_ptr cinfo) { … } /* * Control routine to do upsampling (and color conversion). * * The control routine just handles the row buffering considerations. */ METHODDEF(void) merged_2v_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) /* 2:1 vertical sampling case: may need a spare row. */ { … } METHODDEF(void) merged_1v_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) /* 1:1 vertical sampling case: much easier, never need a spare row. */ { … } /* * These are the routines invoked by the control routines to do * the actual upsampling/conversion. One row group is processed per call. * * Note: since we may be writing directly into application-supplied buffers, * we have to be honest about the output width; we can't assume the buffer * has been rounded up to an even width. */ /* * Upsample and color convert for the case of 2:1 horizontal and 1:1 vertical. */ METHODDEF(void) h2v1_merged_upsample(j_decompress_ptr cinfo, JSAMPIMAGE input_buf, JDIMENSION in_row_group_ctr, JSAMPARRAY output_buf) { … } /* * Upsample and color convert for the case of 2:1 horizontal and 2:1 vertical. */ METHODDEF(void) h2v2_merged_upsample(j_decompress_ptr cinfo, JSAMPIMAGE input_buf, JDIMENSION in_row_group_ctr, JSAMPARRAY output_buf) { … } /* * RGB565 conversion */ #define PACK_SHORT_565_LE(r, g, b) … #define PACK_SHORT_565_BE(r, g, b) … #define PACK_TWO_PIXELS_LE(l, r) … #define PACK_TWO_PIXELS_BE(l, r) … #define WRITE_TWO_PIXELS_LE(addr, pixels) … #define WRITE_TWO_PIXELS_BE(addr, pixels) … #define DITHER_565_R(r, dither) … #define DITHER_565_G(g, dither) … #define DITHER_565_B(b, dither) … /* Declarations for ordered dithering * * We use a 4x4 ordered dither array packed into 32 bits. This array is * sufficient for dithering RGB888 to RGB565. */ #define DITHER_MASK … #define DITHER_ROTATE(x) … static const JLONG dither_matrix[4] = …; /* Include inline routines for RGB565 conversion */ #define PACK_SHORT_565 … #define PACK_TWO_PIXELS … #define WRITE_TWO_PIXELS … #define h2v1_merged_upsample_565_internal … #define h2v1_merged_upsample_565D_internal … #define h2v2_merged_upsample_565_internal … #define h2v2_merged_upsample_565D_internal … #include "jdmrg565.c" #undef PACK_SHORT_565 #undef PACK_TWO_PIXELS #undef WRITE_TWO_PIXELS #undef h2v1_merged_upsample_565_internal #undef h2v1_merged_upsample_565D_internal #undef h2v2_merged_upsample_565_internal #undef h2v2_merged_upsample_565D_internal #define PACK_SHORT_565 … #define PACK_TWO_PIXELS … #define WRITE_TWO_PIXELS … #define h2v1_merged_upsample_565_internal … #define h2v1_merged_upsample_565D_internal … #define h2v2_merged_upsample_565_internal … #define h2v2_merged_upsample_565D_internal … #include "jdmrg565.c" #undef PACK_SHORT_565 #undef PACK_TWO_PIXELS #undef WRITE_TWO_PIXELS #undef h2v1_merged_upsample_565_internal #undef h2v1_merged_upsample_565D_internal #undef h2v2_merged_upsample_565_internal #undef h2v2_merged_upsample_565D_internal static INLINE boolean is_big_endian(void) { … } METHODDEF(void) h2v1_merged_upsample_565(j_decompress_ptr cinfo, JSAMPIMAGE input_buf, JDIMENSION in_row_group_ctr, JSAMPARRAY output_buf) { … } METHODDEF(void) h2v1_merged_upsample_565D(j_decompress_ptr cinfo, JSAMPIMAGE input_buf, JDIMENSION in_row_group_ctr, JSAMPARRAY output_buf) { … } METHODDEF(void) h2v2_merged_upsample_565(j_decompress_ptr cinfo, JSAMPIMAGE input_buf, JDIMENSION in_row_group_ctr, JSAMPARRAY output_buf) { … } METHODDEF(void) h2v2_merged_upsample_565D(j_decompress_ptr cinfo, JSAMPIMAGE input_buf, JDIMENSION in_row_group_ctr, JSAMPARRAY output_buf) { … } /* * Module initialization routine for merged upsampling/color conversion. * * NB: this is called under the conditions determined by use_merged_upsample() * in jdmaster.c. That routine MUST correspond to the actual capabilities * of this module; no safety checks are made here. */ GLOBAL(void) jinit_merged_upsampler(j_decompress_ptr cinfo) { … } #endif /* UPSAMPLE_MERGING_SUPPORTED */
Codebase Browser
chromium