path: root/drivers/media/video/pwc/pwc-dec23.c

/* Linux driver for Philips webcam
   Decompression for chipset version 2 et 3
   (C) 2004-2006  Luc Saillard (luc@saillard.org)

   NOTE: this version of pwc is an unofficial (modified) release of pwc & pcwx
   driver and thus may have bugs that are not present in the original version.
   Please send bug reports and support requests to <luc@saillard.org>.
   The decompression routines have been implemented by reverse-engineering the
   Nemosoft binary pwcx module. Caveat emptor.

   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 program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software
   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

*/

#include "pwc-timon.h"
#include "pwc-kiara.h"
#include "pwc-dec23.h"
#include <media/pwc-ioctl.h>

#include <linux/string.h>

/*
 * USE_LOOKUP_TABLE_TO_CLAMP
 *   0: use a C version of this tests:  {  a<0?0:(a>255?255:a) }
 *   1: use a faster lookup table for cpu with a big cache (intel)
 */
#define USE_LOOKUP_TABLE_TO_CLAMP	1
/*
 * UNROLL_LOOP_FOR_COPYING_BLOCK
 *   0: use a loop for a smaller code (but little slower)
 *   1: when unrolling the loop, gcc produces some faster code (perhaps only
 *   valid for intel processor class). Activating this option, automaticaly
 *   activate USE_LOOKUP_TABLE_TO_CLAMP
 */
#define UNROLL_LOOP_FOR_COPY		1
#if UNROLL_LOOP_FOR_COPY
# undef USE_LOOKUP_TABLE_TO_CLAMP
# define USE_LOOKUP_TABLE_TO_CLAMP 1
#endif

/*
 * ENABLE_BAYER_DECODER
 *   0: bayer decoder is not build (save some space)
 *   1: bayer decoder is build and can be used
 */
#define ENABLE_BAYER_DECODER 0

static void build_subblock_pattern(struct pwc_dec23_private *pdec)
{
	static const unsigned int initial_values[12] = {
		-0x526500, -0x221200, 0x221200, 0x526500,
			   -0x3de200, 0x3de200,
		-0x6db480, -0x2d5d00, 0x2d5d00, 0x6db480,
			   -0x12c200, 0x12c200

	};
	static const unsigned int values_derivated[12] = {
		0xa4ca, 0x4424, -0x4424, -0xa4ca,
			0x7bc4, -0x7bc4,
		0xdb69, 0x5aba, -0x5aba, -0xdb69,
			0x2584, -0x2584
	};
	unsigned int temp_values[12];
	int i, j;

	memcpy(temp_values, initial_values, sizeof(initial_values));
	for (i = 0; i < 256; i++) {
		for (j = 0; j < 12; j++) {
			pdec->table_subblock[i][j] = temp_values[j];
			temp_values[j] += values_derivated[j];
		}
	}
}

static void build_bit_powermask_table(struct pwc_dec23_private *pdec)
{
	unsigned char *p;
	unsigned int bit, byte, mask, val;
	unsigned int bitpower = 1;

	for (bit = 0; bit < 8; bit++) {
		mask = bitpower - 1;
		p = pdec->table_bitpowermask[bit];
		for (byte = 0; byte < 256; byte++) {
			val = (byte & mask);
			if (byte & bitpower)
				val = -val;
			*p++ = val;
		}
		bitpower<<=1;
	}
}


static void build_table_color(const unsigned int romtable[16][8],
			      unsigned char p0004[16][1024],
			      unsigned char p8004[16][256])
{
	int compression_mode, j, k, bit, pw;
	unsigned char *p0, *p8;
	const unsigned int *r;

	/* We have 16 compressions tables */
	for (compression_mode = 0; compression_mode < 16; compression_mode++) {
		p0 = p0004[compression_mode];
		p8 = p8004[compression_mode];
		r  = romtable[compression_mode];

		for (j = 0; j < 8; j++, r++, p0 += 128) {

			for (k = 0; k < 16; k++) {
				if (k == 0)
					bit = 1;
				else if (k >= 1 && k < 3)
					bit = (r[0] >> 15) & 7;
				else if (k >= 3 && k < 6)
					bit = (r[0] >> 12) & 7;
				else if (k >= 6 && k < 10)
					bit = (r[0] >> 9) & 7;
				else if (k >= 10 && k < 13)
					bit = (r[0] >> 6) & 7;
				else if (k >= 13 && k < 15)
					bit = (r[0] >> 3) & 7;
				else
					bit = (r[0]) & 7;
				if (k ==