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/*
* Basic BMP data process and Raw picture data handle functions.
* Could be used to adjust pixel data format, get information, etc.
*
* Copyright (C) 2011 Wayne Xia <xiawenc@cn.ibm.com>
*
* This work is licensed under the terms of the GNU LGPLv3.
*/
#include "malloc.h" // malloc_tmphigh
#include "string.h" // memcpy
#include "util.h" // struct bmp_decdata
struct bmp_decdata {
struct tagRGBQUAD *quadp;
unsigned char *datap;
int width;
int height;
int bpp;
};
#define bmp_load4byte(addr) (*(u32 *)(addr))
#define bmp_load2byte(addr) (*(u16 *)(addr))
typedef struct tagBITMAPFILEHEADER {
u8 bfType[2];
u8 bfSize[4];
u8 bfReserved1[2];
u8 bfReserved2[2];
u8 bfOffBits[4];
} BITMAPFILEHEADER, tagBITMAPFILEHEADER;
typedef struct tagBITMAPINFOHEADER {
u8 biSize[4];
u8 biWidth[4];
u8 biHeight[4];
u8 biPlanes[2];
u8 biBitCount[2];
u8 biCompression[4];
u8 biSizeImage[4];
u8 biXPelsPerMeter[4];
u8 biYPelsPerMeter[4];
u8 biClrUsed[4];
u8 biClrImportant[4];
} BITMAPINFOHEADER, tagBITMAPINFOHEADER;
typedef struct tagRGBQUAD {
u8 rgbBlue;
u8 rgbGreen;
u8 rgbRed;
u8 rgbReserved;
} RGBQUAD, tagRGBQUAD;
/* flat picture data adjusting function
* description:
* switch the vertical line sequence
* arrange horizontal pixel data, add extra space in the dest buffer
* for every line
*/
static void raw_data_format_adjust(u8 *src, u8 *dest, int width,
int height, int bytes_per_line_src, int bytes_per_line_dest)
{
int i;
for (i = 0 ; i < height ; i++) {
memcpy(dest + i * bytes_per_line_dest,
src + (height - 1 - i) * bytes_per_line_src, bytes_per_line_src);
}
}
/* allocate decdata struct */
struct bmp_decdata *bmp_alloc(void)
{
struct bmp_decdata *bmp = malloc_tmphigh(sizeof(*bmp));
return bmp;
}
/* extract information from bmp file data */
int bmp_decode(struct bmp_decdata *bmp, unsigned char *data, int data_size)
{
if (data_size < 54)
return 1;
u16 bmp_filehead = bmp_load2byte(data + 0);
if (bmp_filehead != 0x4d42)
return 2;
u32 bmp_recordsize = bmp_load4byte(data + 2);
if (bmp_recordsize != data_size)
return 3;
u32 bmp_dataoffset = bmp_load4byte(data + 10);
bmp->datap = (unsigned char *)data + bmp_dataoffset;
bmp->width = bmp_load4byte(data + 18);
bmp->height = bmp_load4byte(data + 22);
bmp->bpp = bmp_load2byte(data + 28);
return 0;
}
/* get bmp properties */
void bmp_get_info(struct bmp_decdata *bmp, int *width, int *height, int *bpp)
{
*width = bmp->width;
*height = bmp->height;
*bpp = bmp->bpp;
}
/* flush flat picture data to *pc */
int bmp_show(struct bmp_decdata *bmp, unsigned char *pic, int width,
int height, int depth, int bytes_per_line_dest)
{
if (bmp->datap == pic)
return 0;
if ((depth == bmp->bpp) && (bmp->bpp%8 == 0)) {
raw_data_format_adjust(bmp->datap, pic, width, height,
(bmp->bpp/8)*width, bytes_per_line_dest);
return 0;
}
return 1;
}
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