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rockbox/apps/plugins/imageviewer/jpeg/yuv2rgb.c
Aidan MacDonald f373c97c90 Define LCD_STRIDEFORMAT unconditionally 
Instead of putting "#ifdef LCD_STRIDEFORMAT" at every usage of the
macro it's simpler to have config.h define LCD_STRIDEFORMAT to the
default of horizontal stride when the target leaves it unspecified.

Change-Id: Ib187012aad65ac678dbd837b1464a83bad722411
2022-09-30 10:42:49 +01:00

409 lines
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/***************************************************************************
* __________ __ ___.
* Open \______ \ ____ ____ | | _\_ |__ _______ ___
* Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ /
* Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < <
* Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \
* \/ \/ \/ \/ \/
* $Id$
*
* JPEG image viewer
* (This is a real mess if it has to be coded in one single C file)
*
* File scrolling addition (C) 2005 Alexander Spyridakis
* Copyright (C) 2004 Jörg Hohensohn aka [IDC]Dragon
* Heavily borrowed from the IJG implementation (C) Thomas G. Lane
* Small & fast downscaling IDCT (C) 2002 by Guido Vollbeding JPEGclub.org
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
* KIND, either express or implied.
*
****************************************************************************/
#include "plugin.h"
#include "yuv2rgb.h"
/*
* Conversion of full 0-255 range YCrCb to RGB:
* |R| |1.000000 -0.000001 1.402000| |Y'|
* |G| = |1.000000 -0.334136 -0.714136| |Pb|
* |B| |1.000000 1.772000 0.000000| |Pr|
* Scaled (yields s15-bit output):
* |R| |128 0 179| |Y |
* |G| = |128 -43 -91| |Cb - 128|
* |B| |128 227 0| |Cr - 128|
*/
#define YFAC 128
#define RVFAC 179
#define GUFAC (-43)
#define GVFAC (-91)
#define BUFAC 227
#define YUV_WHITE (255*YFAC)
#define NODITHER_DELTA (127*YFAC)
#define COMPONENT_SHIFT 15
#define MATRIX_SHIFT 7
static inline int clamp_component_bits(int x, int bits)
{
if ((unsigned)x > (1u << bits) - 1)
x = x < 0 ? 0 : (1 << bits) - 1;
return x;
}
static inline int component_to_lcd(int x, int bits, int delta)
{
/* Formula used in core bitmap loader. */
return (((1 << bits) - 1)*x + (x >> (8 - bits)) + delta) >> COMPONENT_SHIFT;
}
static inline int lcd_to_component(int x, int bits, int delta)
{
/* Reasonable, approximate reversal to get a full range back from the
quantized value. */
return YUV_WHITE*x / ((1 << bits) - 1);
(void)delta;
}
#define RED 0
#define GRN 1
#define BLU 2
struct rgb_err
{
int16_t errbuf[LCD_WIDTH+2]; /* Error record for line below */
} rgb_err_buffers[3];
struct rgb_pixel
{
int r, g, b; /* Current pixel components in s16.0 */
int inc; /* Current line increment (-1 or 1) */
int row; /* Current row in source image */
int col; /* Current column in source image */
int ce[3]; /* Errors to apply to current pixel */
struct rgb_err *e; /* RED, GRN, BLU */
int epos; /* Current position in error record */
};
struct rgb_pixel *pixel;
/** round and truncate to lcd depth **/
static fb_data pixel_to_lcd_colour(void)
{
struct rgb_pixel *p = pixel;
int r, g, b;
r = component_to_lcd(p->r, LCD_RED_BITS, NODITHER_DELTA);
r = clamp_component_bits(r, LCD_RED_BITS);
g = component_to_lcd(p->g, LCD_GREEN_BITS, NODITHER_DELTA);
g = clamp_component_bits(g, LCD_GREEN_BITS);
b = component_to_lcd(p->b, LCD_BLUE_BITS, NODITHER_DELTA);
b = clamp_component_bits(b, LCD_BLUE_BITS);
return FB_RGBPACK_LCD(r, g, b);
}
/** write a monochrome pixel to the colour LCD **/
static fb_data pixel_to_lcd_gray(void)
{
int r, g, b;
g = clamp_component(pixel->g);
r = component_to_lcd(g, LCD_RED_BITS, NODITHER_DELTA);
b = component_to_lcd(g, LCD_BLUE_BITS, NODITHER_DELTA);
g = component_to_lcd(g, LCD_GREEN_BITS, NODITHER_DELTA);
return FB_RGBPACK_LCD(r, g, b);
}
/**
* Bayer ordered dithering - swiped from the core bitmap loader.
*/
static fb_data pixel_odither_to_lcd(void)
{
/* canonical ordered dither matrix */
static const unsigned char dither_matrix[16][16] = {
{ 0,192, 48,240, 12,204, 60,252, 3,195, 51,243, 15,207, 63,255 },
{ 128, 64,176,112,140, 76,188,124,131, 67,179,115,143, 79,191,127 },
{ 32,224, 16,208, 44,236, 28,220, 35,227, 19,211, 47,239, 31,223 },
{ 160, 96,144, 80,172,108,156, 92,163, 99,147, 83,175,111,159, 95 },
{ 8,200, 56,248, 4,196, 52,244, 11,203, 59,251, 7,199, 55,247 },
{ 136, 72,184,120,132, 68,180,116,139, 75,187,123,135, 71,183,119 },
{ 40,232, 24,216, 36,228, 20,212, 43,235, 27,219, 39,231, 23,215 },
{ 168,104,152, 88,164,100,148, 84,171,107,155, 91,167,103,151, 87 },
{ 2,194, 50,242, 14,206, 62,254, 1,193, 49,241, 13,205, 61,253 },
{ 130, 66,178,114,142, 78,190,126,129, 65,177,113,141, 77,189,125 },
{ 34,226, 18,210, 46,238, 30,222, 33,225, 17,209, 45,237, 29,221 },
{ 162, 98,146, 82,174,110,158, 94,161, 97,145, 81,173,109,157, 93 },
{ 10,202, 58,250, 6,198, 54,246, 9,201, 57,249, 5,197, 53,245 },
{ 138, 74,186,122,134, 70,182,118,137, 73,185,121,133, 69,181,117 },
{ 42,234, 26,218, 38,230, 22,214, 41,233, 25,217, 37,229, 21,213 },
{ 170,106,154, 90,166,102,150, 86,169,105,153, 89,165,101,149, 85 }
};
struct rgb_pixel *p = pixel;
int r, g, b, delta;
delta = dither_matrix[p->col & 15][p->row & 15] << MATRIX_SHIFT;
r = component_to_lcd(p->r, LCD_RED_BITS, delta);
r = clamp_component_bits(r, LCD_RED_BITS);
g = component_to_lcd(p->g, LCD_GREEN_BITS, delta);
g = clamp_component_bits(g, LCD_GREEN_BITS);
b = component_to_lcd(p->b, LCD_BLUE_BITS, delta);
b = clamp_component_bits(b, LCD_BLUE_BITS);
p->col += p->inc;
return FB_RGBPACK_LCD(r, g, b);
}
/**
* Floyd/Steinberg dither to lcd depth.
*
* Apply filter to each component in serpentine pattern. Kernel shown for
* L->R scan. Kernel is reversed for R->L.
* * 7
* 3 5 1 (1/16)
*/
static inline void distribute_error(int *ce, struct rgb_err *e,
int err, int epos, int inc)
{
*ce = (7*err >> 4) + e->errbuf[epos+inc];
e->errbuf[epos+inc] = err >> 4;
e->errbuf[epos] += 5*err >> 4;
e->errbuf[epos-inc] += 3*err >> 4;
}
static fb_data pixel_fsdither_to_lcd(void)
{
struct rgb_pixel *p = pixel;
int rc, gc, bc, r, g, b;
int inc, epos;
/* Full components with error terms */
rc = p->r + p->ce[RED];
r = component_to_lcd(rc, LCD_RED_BITS, 0);
r = clamp_component_bits(r, LCD_RED_BITS);
gc = p->g + p->ce[GRN];
g = component_to_lcd(gc, LCD_GREEN_BITS, 0);
g = clamp_component_bits(g, LCD_GREEN_BITS);
bc = p->b + p->ce[BLU];
b = component_to_lcd(bc, LCD_BLUE_BITS, 0);
b = clamp_component_bits(b, LCD_BLUE_BITS);
/* Get pixel errors */
rc -= lcd_to_component(r, LCD_RED_BITS, 0);
gc -= lcd_to_component(g, LCD_GREEN_BITS, 0);
bc -= lcd_to_component(b, LCD_BLUE_BITS, 0);
/* Spead error to surrounding pixels. */
inc = p->inc;
epos = p->epos;
p->epos += inc;
distribute_error(&p->ce[RED], &p->e[RED], rc, epos, inc);
distribute_error(&p->ce[GRN], &p->e[GRN], gc, epos, inc);
distribute_error(&p->ce[BLU], &p->e[BLU], bc, epos, inc);
/* Pack and return pixel */
return FB_RGBPACK_LCD(r, g, b);
}
/* Functions for each output mode, colour then grayscale. */
static fb_data (* const pixel_funcs[COLOUR_NUM_MODES][DITHER_NUM_MODES])(void) =
{
[COLOURMODE_COLOUR] =
{
[DITHER_NONE] = pixel_to_lcd_colour,
[DITHER_ORDERED] = pixel_odither_to_lcd,
[DITHER_DIFFUSION] = pixel_fsdither_to_lcd,
},
[COLOURMODE_GRAY] =
{
[DITHER_NONE] = pixel_to_lcd_gray,
[DITHER_ORDERED] = pixel_odither_to_lcd,
[DITHER_DIFFUSION] = pixel_fsdither_to_lcd,
},
};
/* These defines are used fornormal horizontal strides and vertical strides. */
#if LCD_STRIDEFORMAT == VERTICAL_STRIDE
#define LCDADDR(x, y) (lcd_fb + LCD_HEIGHT*(x) + (y))
#define ROWENDOFFSET (width*LCD_HEIGHT)
#define ROWOFFSET (1)
#define COLOFFSET (LCD_HEIGHT)
#else
#define LCDADDR(x, y) (lcd_fb + LCD_WIDTH*(y) + (x))
#define ROWENDOFFSET (width)
#define ROWOFFSET (LCD_WIDTH)
#define COLOFFSET (1)
#endif
/**
* Draw a partial YUV colour bitmap
*
* Runs serpentine pattern when dithering is DITHER_DIFFUSION, else scan is
* always L->R.
*/
void yuv_bitmap_part(unsigned char *src[3], int csub_x, int csub_y,
int src_x, int src_y, int stride,
int x, int y, int width, int height,
int colour_mode, int dither_mode)
{
struct viewport *vp_main = *(rb->screens[SCREEN_MAIN]->current_viewport);
fb_data *lcd_fb = vp_main->buffer->fb_ptr;
fb_data *dst, *dst_end;
fb_data (*pixel_func)(void);
struct rgb_pixel px;
int dst_inc;
if (x + width > LCD_WIDTH)
width = LCD_WIDTH - x; /* Clip right */
if (x < 0)
width += x, x = 0; /* Clip left */
if (width <= 0)
return; /* nothing left to do */
if (y + height > LCD_HEIGHT)
height = LCD_HEIGHT - y; /* Clip bottom */
if (y < 0)
height += y, y = 0; /* Clip top */
if (height <= 0)
return; /* nothing left to do */
pixel = &px;
dst = LCDADDR(x, y);
dst_end = LCDADDR(x, y+height);
if (colour_mode == COLOURMODE_GRAY)
csub_y = 0; /* Ignore Cb, Cr */
pixel_func = pixel_funcs[colour_mode]
[dither_mode];
if (dither_mode == DITHER_DIFFUSION)
{
/* Reset error terms. */
px.e = rgb_err_buffers;
px.ce[RED] = px.ce[GRN] = px.ce[BLU] = 0;
rb->memset(px.e, 0, 3*sizeof (struct rgb_err));
}
do
{
fb_data *dst_row, *row_end;
const unsigned char *ysrc;
px.inc = 1;
if (dither_mode == DITHER_DIFFUSION)
{
/* Use R->L scan on odd lines */
px.inc -= (src_y & 1) << 1;
px.epos = x + 1;
if (px.inc < 0)
px.epos += width - 1;
}
if (px.inc == 1)
{
/* Scan is L->R */
dst_inc = COLOFFSET;
dst_row = dst;
row_end = dst_row + ROWENDOFFSET;
px.col = src_x;
}
else
{
/* Scan is R->L */
dst_inc = -COLOFFSET;
row_end = dst + dst_inc;
dst_row = row_end + ROWENDOFFSET;
px.col = src_x + width - 1;
}
ysrc = src[0] + stride * src_y + px.col;
px.row = src_y;
/* Do one row of pixels */
if (csub_y) /* colour */
{
/* upsampling, YUV->RGB conversion and reduction to RGB565 in one go */
const unsigned char *usrc, *vsrc;
usrc = src[1] + (stride/csub_x) * (src_y/csub_y)
+ (px.col/csub_x);
vsrc = src[2] + (stride/csub_x) * (src_y/csub_y)
+ (px.col/csub_x);
int xphase = px.col % csub_x;
int xphase_reset = px.inc * csub_x;
int y, v, u, rv, guv, bu;
v = *vsrc - 128;
vsrc += px.inc;
u = *usrc - 128;
usrc += px.inc;
rv = RVFAC*v;
guv = GUFAC*u + GVFAC*v;
bu = BUFAC*u;
while (1)
{
y = YFAC*(*ysrc);
ysrc += px.inc;
px.r = y + rv;
px.g = y + guv;
px.b = y + bu;
*dst_row = pixel_func();
dst_row += dst_inc;
if (dst_row == row_end)
break;
xphase += px.inc;
if ((unsigned)xphase < (unsigned)csub_x)
continue;
/* fetch new chromas */
v = *vsrc - 128;
vsrc += px.inc;
u = *usrc - 128;
usrc += px.inc;
rv = RVFAC*v;
guv = GUFAC*u + GVFAC*v;
bu = BUFAC*u;
xphase -= xphase_reset;
}
}
else /* monochrome */
{
do
{
/* Set all components the same for dithering purposes */
px.g = px.r = px.b = YFAC*(*ysrc);
*dst_row = pixel_func();
ysrc += px.inc;
dst_row += dst_inc;
}
while (dst_row != row_end);
}
src_y++;
dst += ROWOFFSET;
}
while (dst < dst_end);
}
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