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the JPEG core can now also decode color images, this has to be wired to the application (memory management, color space converting display)

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git-svn-id: svn://svn.rockbox.org/rockbox/trunk@8711 a1c6a512-1295-4272-9138-f99709370657
This commit is contained in:
Jörg Hohensohn 2006-02-16 22:59:40 +00:00
parent 7ea4d59127
commit 4c63ab6a6e
1 changed files with 222 additions and 11 deletions
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233
apps/plugins/jpeg.c
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@ -669,7 +669,7 @@ struct jpeg
int x_phys, y_phys; /* physical size, block aligned */
int x_mbl; /* x dimension of MBL */
int y_mbl; /* y dimension of MBL */
int blocks; /* blocks per MBL */
int blocks; /* blocks per MB */
int restart_interval; /* number of MCUs between RSTm markers */
int store_pos[4]; /* for Y block ordering */
@ -688,6 +688,8 @@ struct jpeg
int mcu_membership[6]; /* info per block */
int tab_membership[6];
int subsample_x[3]; /* info per component */
int subsample_y[3];
};
@ -1126,14 +1128,20 @@ void build_lut(struct jpeg* p_jpeg)
p_jpeg->x_phys = p_jpeg->x_mbl * 16;
p_jpeg->y_mbl = (p_jpeg->y_size+7) / 8;
p_jpeg->y_phys = p_jpeg->y_mbl * 8;
p_jpeg->mcu_membership[0] = 0; /* Y1=Y2=0, U=2, V=3 */
p_jpeg->mcu_membership[0] = 0; /* Y1=Y2=0, U=1, V=2 */
p_jpeg->mcu_membership[1] = 0;
p_jpeg->mcu_membership[2] = 2;
p_jpeg->mcu_membership[3] = 3;
p_jpeg->mcu_membership[2] = 1;
p_jpeg->mcu_membership[3] = 2;
p_jpeg->tab_membership[0] = 0; /* DC, DC, AC, AC */
p_jpeg->tab_membership[1] = 0;
p_jpeg->tab_membership[2] = 1;
p_jpeg->tab_membership[3] = 1;
p_jpeg->subsample_x[0] = 1;
p_jpeg->subsample_x[1] = 2;
p_jpeg->subsample_x[2] = 2;
p_jpeg->subsample_y[0] = 1;
p_jpeg->subsample_y[1] = 1;
p_jpeg->subsample_y[2] = 1;
}
if (p_jpeg->frameheader[0].horizontal_sampling == 1
&& p_jpeg->frameheader[0].vertical_sampling == 2)
@ -1145,14 +1153,20 @@ void build_lut(struct jpeg* p_jpeg)
p_jpeg->x_phys = p_jpeg->x_mbl * 8;
p_jpeg->y_mbl = (p_jpeg->y_size+15) / 16;
p_jpeg->y_phys = p_jpeg->y_mbl * 16;
p_jpeg->mcu_membership[0] = 0; /* Y1=Y2=0, U=2, V=3 */
p_jpeg->mcu_membership[0] = 0; /* Y1=Y2=0, U=1, V=2 */
p_jpeg->mcu_membership[1] = 0;
p_jpeg->mcu_membership[2] = 2;
p_jpeg->mcu_membership[3] = 3;
p_jpeg->mcu_membership[2] = 1;
p_jpeg->mcu_membership[3] = 2;
p_jpeg->tab_membership[0] = 0; /* DC, DC, AC, AC */
p_jpeg->tab_membership[1] = 0;
p_jpeg->tab_membership[2] = 1;
p_jpeg->tab_membership[3] = 1;
p_jpeg->subsample_x[0] = 1;
p_jpeg->subsample_x[1] = 1;
p_jpeg->subsample_x[2] = 1;
p_jpeg->subsample_y[0] = 1;
p_jpeg->subsample_y[1] = 2;
p_jpeg->subsample_y[2] = 2;
}
else if (p_jpeg->frameheader[0].horizontal_sampling == 2
&& p_jpeg->frameheader[0].vertical_sampling == 2)
@ -1166,14 +1180,20 @@ void build_lut(struct jpeg* p_jpeg)
p_jpeg->mcu_membership[1] = 0;
p_jpeg->mcu_membership[2] = 0;
p_jpeg->mcu_membership[3] = 0;
p_jpeg->mcu_membership[4] = 2;
p_jpeg->mcu_membership[5] = 3;
p_jpeg->mcu_membership[4] = 1;
p_jpeg->mcu_membership[5] = 2;
p_jpeg->tab_membership[0] = 0;
p_jpeg->tab_membership[1] = 0;
p_jpeg->tab_membership[2] = 0;
p_jpeg->tab_membership[3] = 0;
p_jpeg->tab_membership[4] = 1;
p_jpeg->tab_membership[5] = 1;
p_jpeg->subsample_x[0] = 1;
p_jpeg->subsample_x[1] = 2;
p_jpeg->subsample_x[2] = 2;
p_jpeg->subsample_y[0] = 1;
p_jpeg->subsample_y[1] = 2;
p_jpeg->subsample_y[2] = 2;
}
else if (p_jpeg->frameheader[0].horizontal_sampling == 1
&& p_jpeg->frameheader[0].vertical_sampling == 1)
@ -1184,11 +1204,21 @@ void build_lut(struct jpeg* p_jpeg)
p_jpeg->y_mbl = (p_jpeg->y_size+7) / 8;
p_jpeg->y_phys = p_jpeg->y_mbl * 8;
p_jpeg->mcu_membership[0] = 0;
p_jpeg->mcu_membership[1] = 2;
p_jpeg->mcu_membership[2] = 3;
p_jpeg->mcu_membership[1] = 1;
p_jpeg->mcu_membership[2] = 2;
p_jpeg->tab_membership[0] = 0;
p_jpeg->tab_membership[1] = 1;
p_jpeg->tab_membership[2] = 1;
p_jpeg->subsample_x[0] = 1;
p_jpeg->subsample_x[1] = 1;
p_jpeg->subsample_x[2] = 1;
p_jpeg->subsample_y[0] = 1;
p_jpeg->subsample_y[1] = 1;
p_jpeg->subsample_y[2] = 1;
}
else
{
// error
}
}
@ -1523,6 +1553,187 @@ int jpeg_decode(struct jpeg* p_jpeg, unsigned char* p_pixel, int downscale,
}
#ifdef HAVE_LCD_COLOR
/* JPEG decoder variant for YUV decoding, into 3 different planes */
/* Note: it keeps the original color subsampling, even if resized. */
int jpeg_decode_color(struct jpeg* p_jpeg, unsigned char* p_pixel[3],
int downscale, void (*pf_progress)(int current, int total))
{
struct bitstream bs; /* bitstream "object" */
static int block[64]; /* decoded DCT coefficients */
int width, height;
int skip_line[3]; /* bytes from one line to the next (skip_line) */
int skip_strip[3], skip_mcu[3]; /* bytes to next DCT row / column */
int i, x, y; /* loop counter */
unsigned char* p_line[3] = {p_pixel[0], p_pixel[1], p_pixel[2]};
unsigned char* p_byte[3]; /* bitmap pointer */
void (*pf_idct)(unsigned char*, int*, int*, int); /* selected IDCT */
int k_need; /* AC coefficients needed up to here */
int zero_need; /* init the block with this many zeros */
int last_dc_val[3] = {0, 0, 0}; // or 128 for chroma?
int store_offs[4]; /* memory offsets: order of Y11 Y12 Y21 Y22 U V */
int restart = p_jpeg->restart_interval; /* MCUs until restart marker */
/* pick the IDCT we want, determine how to work with coefs */
if (downscale == 1)
{
pf_idct = idct8x8;
k_need = 64; /* all */
zero_need = 63; /* all */
}
else if (downscale == 2)
{
pf_idct = idct4x4;
k_need = 25; /* this far in zig-zag to cover 4*4 */
zero_need = 27; /* clear this far in linear order */
}
else if (downscale == 4)
{
pf_idct = idct2x2;
k_need = 5; /* this far in zig-zag to cover 2*2 */
zero_need = 9; /* clear this far in linear order */
}
else if (downscale == 8)
{
pf_idct = idct1x1;
k_need = 0; /* no AC, not needed */
zero_need = 0; /* no AC, not needed */
}
else return -1; /* not supported */
/* init bitstream, fake a restart to make it start */
bs.next_input_byte = p_jpeg->p_entropy_data;
bs.bits_left = 0;
bs.input_end = p_jpeg->p_entropy_end;
width = p_jpeg->x_phys / downscale;
height = p_jpeg->y_phys / downscale;
for (i=0; i<3; i++) /* calculate some strides */
{
skip_line[i] = width / p_jpeg->subsample_x[i];
skip_strip[i] = skip_line[i]
* (height / p_jpeg->y_mbl) / p_jpeg->subsample_y[i];
skip_mcu[i] = width/p_jpeg->x_mbl / p_jpeg->subsample_x[i];
}
/* prepare offsets about where to store the different blocks */
store_offs[p_jpeg->store_pos[0]] = 0;
store_offs[p_jpeg->store_pos[1]] = 8 / downscale; /* to the right */
store_offs[p_jpeg->store_pos[2]] = width * 8 / downscale; /* below */
store_offs[p_jpeg->store_pos[3]] = store_offs[1] + store_offs[2]; /* r+b */
for(y=0; y<p_jpeg->y_mbl && bs.next_input_byte <= bs.input_end; y++)
{
for (i=0; i<3; i++) // scan line init
{
p_byte[i] = p_line[i];
p_line[i] += skip_strip[i];
}
for (x=0; x<p_jpeg->x_mbl; x++)
{
int blkn;
/* Outer loop handles each block in the MCU */
for (blkn = 0; blkn < p_jpeg->blocks; blkn++)
{ /* Decode a single block's worth of coefficients */
int k = 1; /* coefficient index */
int s, r; /* huffman values */
int ci = p_jpeg->mcu_membership[blkn]; /* component index */
int ti = p_jpeg->tab_membership[blkn]; /* table index */
struct derived_tbl* dctbl = &p_jpeg->dc_derived_tbls[ti];
struct derived_tbl* actbl = &p_jpeg->ac_derived_tbls[ti];
/* Section F.2.2.1: decode the DC coefficient difference */
s = huff_decode_dc(&bs, dctbl);
last_dc_val[ci] += s;
block[0] = last_dc_val[ci]; /* output it (assumes zag[0] = 0) */
/* coefficient buffer must be cleared */
MEMSET(block+1, 0, zero_need*sizeof(block[0]));
/* Section F.2.2.2: decode the AC coefficients */
for (; k < k_need; k++)
{
s = huff_decode_ac(&bs, actbl);
r = s >> 4;
s &= 15;
if (s)
{
k += r;
check_bit_buffer(&bs, s);
r = get_bits(&bs, s);
block[zag[k]] = HUFF_EXTEND(r, s);
}
else
{
if (r != 15)
{
k = 64;
break;
}
k += r;
}
} /* for k */
/* In this path we just discard the values */
for (; k < 64; k++)
{
s = huff_decode_ac(&bs, actbl);
r = s >> 4;
s &= 15;
if (s)
{
k += r;
check_bit_buffer(&bs, s);
drop_bits(&bs, s);
}
else
{
if (r != 15)
break;
k += r;
}
} /* for k */
if (ci == 0)
{ /* Y component needs to bother about block store */
pf_idct(p_byte[0]+store_offs[blkn], block,
p_jpeg->qt_idct[ti], skip_line[0]);
}
else
{ /* chroma */
pf_idct(p_byte[ci], block, p_jpeg->qt_idct[ti],
skip_line[ci]);
}
} /* for blkn */
p_byte[0] += skip_mcu[0]; // unrolled for (i=0; i<3; i++) loop
p_byte[1] += skip_mcu[1];
p_byte[2] += skip_mcu[2];
if (p_jpeg->restart_interval && --restart == 0)
{ /* if a restart marker is due: */
restart = p_jpeg->restart_interval; /* count again */
search_restart(&bs); /* align the bitstream */
last_dc_val[0] = last_dc_val[1] =
last_dc_val[2] = 0; /* reset decoder */
}
} /* for x */
if (pf_progress != NULL)
pf_progress(y, p_jpeg->y_mbl-1); /* notify about decoding progress */
} /* for y */
return 0; /* success */
}
#endif /* #ifdef HAVE_LCD_COLOR */
/**************** end JPEG code ********************/