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foxbox/apps/plugins/jpeg/yuv2rgb.c
Andrew Mahone 23d9812273 loader-initialized global plugin API:
struct plugin_api *rb is declared in PLUGIN_HEADER, and pointed to by
__header.api

the loader uses this pointer to initialize rb before calling entry_point

entry_point is no longer passed a pointer to the plugin API

all plugins, and pluginlib functions, are modified to refer to the
global rb

pluginlib functions which only served to copy the API pointer are
removed

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@19776 a1c6a512-1295-4272-9138-f99709370657
2009-01-16 10:34:40 +00:00

398 lines
12 KiB
C

/***************************************************************************
* __________ __ ___.
* 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(int x)
{
if ((unsigned)x > YUV_WHITE)
x = x < 0 ? 0 : YUV_WHITE;
return x;
}
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 LCD_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 LCD_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 LCD_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 LCD_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,
},
};
/**
* 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)
{
fb_data *dst, *dst_end;
fb_data (*pixel_func)(void);
struct rgb_pixel px;
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 = rb->lcd_framebuffer + LCD_WIDTH * y + x;
dst_end = dst + LCD_WIDTH * 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_row = dst;
row_end = dst_row + width;
px.col = src_x;
}
else
{
/* Scan is R->L */
row_end = dst - 1;
dst_row = row_end + width;
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 += px.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 += px.inc;
}
while (dst_row != row_end);
}
src_y++;
dst += LCD_WIDTH;
}
while (dst < dst_end);
}