V4L/DVB (3835): [PATCH] update pwc driver

Add v4l2 compatibility
Include the decompressor (legal problem has been resolv by Alan Cox)
Faster decoder and easier to maintain, optimize, ...
Can export to userland compressed stream
Support more cameras, lot of bugs are fixed.

Signed-off-by: Luc Saillard <luc@saillard.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>

1 files changed, 941 insertions, 0 deletions

diff --git a/drivers/media/video/pwc/pwc-dec23.c b/drivers/media/video/pwc/pwc-dec23.c
new file mode 100644
index 0000000000000..f9096c72cbb79
--- /dev/null
+++ b/drivers/media/video/pwc/pwc-dec23.c
@@ -0,0 +1,941 @@
+/* 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 == 0)
+					*p8++ = 8;
+				else
+					*p8++ = j - bit;
+				*p8++ = bit;
+
+				pw = 1 << bit;
+				p0[k + 0x00] = (1 * pw) + 0x80;
+				p0[k + 0x10] = (2 * pw) + 0x80;
+				p0[k + 0x20] = (3 * pw) + 0x80;
+				p0[k + 0x30] = (4 * pw) + 0x80;
+				p0[k + 0x40] = (-1 * pw) + 0x80;
+				p0[k + 0x50] = (-2 * pw) + 0x80;
+				p0[k + 0x60] = (-3 * pw) + 0x80;
+				p0[k + 0x70] = (-4 * pw) + 0x80;
+			}	/* end of for (k=0; k<16; k++, p8++) */
+		}	/* end of for (j=0; j<8; j++ , table++) */
+	} /* end of foreach compression_mode */
+}
+
+/*
+ *
+ */
+static void fill_table_dc00_d800(struct pwc_dec23_private *pdec)
+{
+#define SCALEBITS 15
+#define ONE_HALF  (1UL << (SCALEBITS - 1))
+	int i;
+	unsigned int offset1 = ONE_HALF;
+	unsigned int offset2 = 0x0000;
+
+	for (i=0; i<256; i++) {
+		pdec->table_dc00[i] = offset1 & ~(ONE_HALF);
+		pdec->table_d800[i] = offset2;
+
+		offset1 += 0x7bc4;
+		offset2 += 0x7bc4;
+	}
+}
+
+/*
+ * To decode the stream:
+ *   if look_bits(2) == 0:	# op == 2 in the lookup table
+ *      skip_bits(2)
+ *      end of the stream
+ *   elif look_bits(3) == 7:	# op == 1 in the lookup table
+ *      skip_bits(3)
+ *      yyyy = get_bits(4)
+ *      xxxx = get_bits(8)
+ *   else:			# op == 0 in the lookup table
+ *      skip_bits(x)
+ *
+ * For speedup processing, we build a lookup table and we takes the first 6 bits.
+ *
+ * struct {
+ *   unsigned char op;	    // operation to execute
+ *   unsigned char bits;    // bits use to perform operation
+ *   unsigned char offset1; // offset to add to access in the table_0004 % 16
+ *   unsigned char offset2; // offset to add to access in the table_0004
+ * }
+ *
+ * How to build this table ?
+ *   op == 2 when (i%4)==0
+ *   op == 1 when (i%8)==7
+ *   op == 0 otherwise
+ *
+ */
+static const unsigned char hash_table_ops[64*4] = {
+	0x02, 0x00, 0x00, 0x00,
+	0x00, 0x03, 0x01, 0x00,
+	0x00, 0x04, 0x01, 0x10,
+	0x00, 0x06, 0x01, 0x30,
+	0x02, 0x00, 0x00, 0x00,
+	0x00, 0x03, 0x01, 0x40,
+	0x00, 0x05, 0x01, 0x20,
+	0x01, 0x00, 0x00, 0x00,
+	0x02, 0x00, 0x00, 0x00,
+	0x00, 0x03, 0x01, 0x00,
+	0x00, 0x04, 0x01, 0x50,
+	0x00, 0x05, 0x02, 0x00,
+	0x02, 0x00, 0x00, 0x00,
+	0x00, 0x03, 0x01, 0x40,
+	0x00, 0x05, 0x03, 0x00,
+	0x01, 0x00, 0x00, 0x00,
+	0x02, 0x00, 0x00, 0x00,
+	0x00, 0x03, 0x01, 0x00,
+	0x00, 0x04, 0x01, 0x10,
+	0x00, 0x06, 0x02, 0x10,
+	0x02, 0x00, 0x00, 0x00,
+	0x00, 0x03, 0x01, 0x40,
+	0x00, 0x05, 0x01, 0x60,
+	0x01, 0x00, 0x00, 0x00,
+	0x02, 0x00, 0x00, 0x00,
+	0x00, 0x03, 0x01, 0x00,
+	0x00, 0x04, 0x01, 0x50,
+	0x00, 0x05, 0x02, 0x40,
+	0x02, 0x00, 0x00, 0x00,
+	0x00, 0x03, 0x01, 0x40,
+	0x00, 0x05, 0x03, 0x40,
+	0x01, 0x00, 0x00, 0x00,
+	0x02, 0x00, 0x00, 0x00,
+	0x00, 0x03, 0x01, 0x00,
+	0x00, 0x04, 0x01, 0x10,
+	0x00, 0x06, 0x01, 0x70,
+	0x02, 0x00, 0x00, 0x00,
+	0x00, 0x03, 0x01, 0x40,
+	0x00, 0x05, 0x01, 0x20,
+	0x01, 0x00, 0x00, 0x00,
+	0x02, 0x00, 0x00, 0x00,
+	0x00, 0x03, 0x01, 0x00,
+	0x00, 0x04, 0x01, 0x50,
+	0x00, 0x05, 0x02, 0x00,
+	0x02, 0x00, 0x00, 0x00,
+	0x00, 0x03, 0x01, 0x40,
+	0x00, 0x05, 0x03, 0x00,
+	0x01, 0x00, 0x00, 0x00,
+	0x02, 0x00, 0x00, 0x00,
+	0x00, 0x03, 0x01, 0x00,
+	0x00, 0x04, 0x01, 0x10,
+	0x00, 0x06, 0x02, 0x50,
+	0x02, 0x00, 0x00, 0x00,
+	0x00, 0x03, 0x01, 0x40,
+	0x00, 0x05, 0x01, 0x60,
+	0x01, 0x00, 0x00, 0x00,
+	0x02, 0x00, 0x00, 0x00,
+	0x00, 0x03, 0x01, 0x00,
+	0x00, 0x04, 0x01, 0x50,
+	0x00, 0x05, 0x02, 0x40,
+	0x02, 0x00, 0x00, 0x00,
+	0x00, 0x03, 0x01, 0x40,
+	0x00, 0x05, 0x03, 0x40,
+	0x01, 0x00, 0x00, 0x00
+};
+
+/*
+ *
+ */
+static const unsigned int MulIdx[16][16] = {
+	{0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,},
+	{0, 1, 2, 3, 0, 1, 2, 3, 0, 1, 2, 3, 0, 1, 2, 3,},
+	{0, 0, 0, 0, 1, 1, 1, 1, 2, 2, 2, 2, 3, 3, 3, 3,},
+	{4, 4, 4, 4, 5, 5, 5, 5, 5, 5, 5, 5, 4, 4, 4, 4,},
+	{6, 7, 8, 9, 7, 10, 11, 8, 8, 11, 10, 7, 9, 8, 7, 6,},
+	{4, 5, 5, 4, 4, 5, 5, 4, 4, 5, 5, 4, 4, 5, 5, 4,},
+	{1, 3, 0, 2, 1, 3, 0, 2, 1, 3, 0, 2, 1, 3, 0, 2,},
+	{0, 3, 3, 0, 1, 2, 2, 1, 2, 1, 1, 2, 3, 0, 0, 3,},
+	{0, 1, 2, 3, 3, 2, 1, 0, 3, 2, 1, 0, 0, 1, 2, 3,},
+	{1, 1, 1, 1, 3, 3, 3, 3, 0, 0, 0, 0, 2, 2, 2, 2,},
+	{7, 10, 11, 8, 9, 8, 7, 6, 6, 7, 8, 9, 8, 11, 10, 7,},
+	{4, 5, 5, 4, 5, 4, 4, 5, 5, 4, 4, 5, 4, 5, 5, 4,},
+	{7, 9, 6, 8, 10, 8, 7, 11, 11, 7, 8, 10, 8, 6, 9, 7,},
+	{1, 3, 0, 2, 2, 0, 3, 1, 2, 0, 3, 1, 1, 3, 0, 2,},
+	{1, 2, 2, 1, 3, 0, 0, 3, 0, 3, 3, 0, 2, 1, 1, 2,},
+	{10, 8, 7, 11, 8, 6, 9, 7, 7, 9, 6, 8, 11, 7, 8, 10}
+};
+
+#if USE_LOOKUP_TABLE_TO_CLAMP
+#define MAX_OUTER_CROP_VALUE	(512)
+static unsigned char pwc_crop_table[256 + 2*MAX_OUTER_CROP_VALUE];
+#define CLAMP(x) (pwc_crop_table[MAX_OUTER_CROP_VALUE+(x)])
+#else
+#define CLAMP(x) ((x)>255?255:((x)<0?0:x))
+#endif
+
+
+/* If the type or the command change, we rebuild the lookup table */
+int pwc_dec23_init(struct pwc_device *pwc, int type, unsigned char *cmd)
+{
+	int flags, version, shift, i;
+	struct pwc_dec23_private *pdec;
+
+	if (pwc->decompress_data == NULL) {
+		pdec = kmalloc(sizeof(struct pwc_dec23_private), GFP_KERNEL);
+		if (pdec == NULL)
+			return -ENOMEM;
+		pwc->decompress_data = pdec;
+	}
+	pdec = pwc->decompress_data;
+
+	if (DEVICE_USE_CODEC3(type)) {
+		flags = cmd[2] & 0x18;
+		if (flags == 8)
+			pdec->nbits = 7;	/* More bits, mean more bits to encode the stream, but better quality */
+		else if (flags == 0x10)
+			pdec->nbits = 8;
+		else
+			pdec->nbits = 6;
+
+		version = cmd[2] >> 5;
+		build_table_color(KiaraRomTable[version][0], pdec->table_0004_pass1, pdec->table_8004_pass1);
+		build_table_color(KiaraRomTable[version][1], pdec->table_0004_pass2, pdec->table_8004_pass2);
+
+	} else {
+
+		flags = cmd[2] & 6;
+		if (flags == 2)
+			pdec->nbits = 7;
+		else if (flags == 4)
+			pdec->nbits = 8;
+		else
+			pdec->nbits = 6;
+
+		version = cmd[2] >> 3;
+		build_table_color(TimonRomTable[version][0], pdec->table_0004_pass1, pdec->table_8004_pass1);
+		build_table_color(TimonRomTable[version][1], pdec->table_0004_pass2, pdec->table_8004_pass2);
+	}
+
+	/* Informations can be coded on a variable number of bits but never less than 8 */
+	shift = 8 - pdec->nbits;
+	pdec->scalebits = SCALEBITS - shift;
+	pdec->nbitsmask = 0xFF >> shift;
+
+	fill_table_dc00_d800(pdec);
+	build_subblock_pattern(pdec);
+	build_bit_powermask_table(pdec);
+
+#if USE_LOOKUP_TABLE_TO_CLAMP
+	/* Build the static table to clamp value [0-255] */
+	for (i=0;i<MAX_OUTER_CROP_VALUE;i++)
+		pwc_crop_table[i] = 0;
+	for (i=0; i<256; i++)
+		pwc_crop_table[MAX_OUTER_CROP_VALUE+i] = i;
+	for (i=0; i<MAX_OUTER_CROP_VALUE; i++)
+		pwc_crop_table[MAX_OUTER_CROP_VALUE+256+i] = 255;
+#endif
+
+	return 0;
+}
+
+/*
+ * Copy the 4x4 image block to Y plane buffer
+ */
+static void copy_image_block_Y(const int *src, unsigned char *dst, unsigned int bytes_per_line, unsigned int scalebits)
+{
+#if UNROLL_LOOP_FOR_COPY
+	const unsigned char *cm = pwc_crop_table+MAX_OUTER_CROP_VALUE;
+	const int *c = src;
+	unsigned char *d = dst;
+
+	*d++ = cm[c[0] >> scalebits];
+	*d++ = cm[c[1] >> scalebits];
+	*d++ = cm[c[2] >> scalebits];
+	*d++ = cm[c[3] >> scalebits];
+
+	d = dst + bytes_per_line;
+	*d++ = cm[c[4] >> scalebits];
+	*d++ = cm[c[5] >> scalebits];
+	*d++ = cm[c[6] >> scalebits];
+	*d++ = cm[c[7] >> scalebits];
+
+	d = dst + bytes_per_line*2;
+	*d++ = cm[c[8] >> scalebits];
+	*d++ = cm[c[9] >> scalebits];
+	*d++ = cm[c[10] >> scalebits];
+	*d++ = cm[c[11] >> scalebits];
+
+	d = dst + bytes_per_line*3;
+	*d++ = cm[c[12] >> scalebits];
+	*d++ = cm[c[13] >> scalebits];
+	*d++ = cm[c[14] >> scalebits];
+	*d++ = cm[c[15] >> scalebits];
+#else
+	int i;
+	const int *c = src;
+	unsigned char *d = dst;
+	for (i = 0; i < 4; i++, c++)
+		*d++ = CLAMP((*c) >> scalebits);
+
+	d = dst + bytes_per_line;
+	for (i = 0; i < 4; i++, c++)
+		*d++ = CLAMP((*c) >> scalebits);
+
+	d = dst + bytes_per_line*2;
+	for (i = 0; i < 4; i++, c++)
+		*d++ = CLAMP((*c) >> scalebits);
+
+	d = dst + bytes_per_line*3;
+	for (i = 0; i < 4; i++, c++)
+		*d++ = CLAMP((*c) >> scalebits);
+#endif
+}
+
+/*
+ * Copy the 4x4 image block to a CrCb plane buffer
+ *
+ */
+static void copy_image_block_CrCb(const int *src, unsigned char *dst, unsigned int bytes_per_line, unsigned int scalebits)
+{
+#if UNROLL_LOOP_FOR_COPY
+	/* Unroll all loops */
+	const unsigned char *cm = pwc_crop_table+MAX_OUTER_CROP_VALUE;
+	const int *c = src;
+	unsigned char *d = dst;
+
+	*d++ = cm[c[0] >> scalebits];
+	*d++ = cm[c[4] >> scalebits];
+	*d++ = cm[c[1] >> scalebits];
+	*d++ = cm[c[5] >> scalebits];
+	*d++ = cm[c[2] >> scalebits];
+	*d++ = cm[c[6] >> scalebits];
+	*d++ = cm[c[3] >> scalebits];
+	*d++ = cm[c[7] >> scalebits];
+
+	d = dst + bytes_per_line;
+	*d++ = cm[c[12] >> scalebits];
+	*d++ = cm[c[8] >> scalebits];
+	*d++ = cm[c[13] >> scalebits];
+	*d++ = cm[c[9] >> scalebits];
+	*d++ = cm[c[14] >> scalebits];
+	*d++ = cm[c[10] >> scalebits];
+	*d++ = cm[c[15] >> scalebits];
+	*d++ = cm[c[11] >> scalebits];
+#else
+	int i;
+	const int *c1 = src;
+	const int *c2 = src + 4;
+	unsigned char *d = dst;
+
+	for (i = 0; i < 4; i++, c1++, c2++) {
+		*d++ = CLAMP((*c1) >> scalebits);
+		*d++ = CLAMP((*c2) >> scalebits);
+	}
+	c1 = src + 12;
+	d = dst + bytes_per_line;
+	for (i = 0; i < 4; i++, c1++, c2++) {
+		*d++ = CLAMP((*c1) >> scalebits);
+		*d++ = CLAMP((*c2) >> scalebits);
+	}
+#endif
+}
+
+#if ENABLE_BAYER_DECODER
+/*
+ * Format: 8x2 pixels
+ *   . G . G . G . G . G . G . G
+ *   . . . . . . . . . . . . . .
+ *   . G . G . G . G . G . G . G
+ *   . . . . . . . . . . . . . .
+ *   or
+ *   . . . . . . . . . . . . . .
+ *   G . G . G . G . G . G . G .
+ *   . . . . . . . . . . . . . .
+ *   G . G . G . G . G . G . G .
+*/
+static void copy_image_block_Green(const int *src, unsigned char *dst, unsigned int bytes_per_line, unsigned int scalebits)
+{
+#if UNROLL_LOOP_FOR_COPY
+	/* Unroll all loops */
+	const unsigned char *cm = pwc_crop_table+MAX_OUTER_CROP_VALUE;
+	unsigned char *d = dst;
+	const int *c = src;
+
+	d[0] = cm[c[0] >> scalebits];
+	d[2] = cm[c[1] >> scalebits];
+	d[4] = cm[c[2] >> scalebits];
+	d[6] = cm[c[3] >> scalebits];
+	d[8] = cm[c[4] >> scalebits];
+	d[10] = cm[c[5] >> scalebits];
+	d[12] = cm[c[6] >> scalebits];
+	d[14] = cm[c[7] >> scalebits];
+
+	d = dst + bytes_per_line;
+	d[0] = cm[c[8] >> scalebits];
+	d[2] = cm[c[9] >> scalebits];
+	d[4] = cm[c[10] >> scalebits];
+	d[6] = cm[c[11] >> scalebits];
+	d[8] = cm[c[12] >> scalebits];
+	d[10] = cm[c[13] >> scalebits];
+	d[12] = cm[c[14] >> scalebits];
+	d[14] = cm[c[15] >> scalebits];
+#else
+	int i;
+	unsigned char *d;
+	const int *c = src;
+
+	d = dst;
+	for (i = 0; i < 8; i++, c++)
+		d[i*2] = CLAMP((*c) >> scalebits);
+
+	d = dst + bytes_per_line;
+	for (i = 0; i < 8; i++, c++)
+		d[i*2] = CLAMP((*c) >> scalebits);
+#endif
+}
+#endif
+
+#if ENABLE_BAYER_DECODER
+/*
+ * Format: 4x4 pixels
+ *   R . R . R . R
+ *   . B . B . B .
+ *   R . R . R . R
+ *   . B . B . B .
+ */
+static void copy_image_block_RedBlue(const int *src, unsigned char *dst, unsigned int bytes_per_line, unsigned int scalebits)
+{
+#if UNROLL_LOOP_FOR_COPY
+	/* Unroll all loops */
+	const unsigned char *cm = pwc_crop_table+MAX_OUTER_CROP_VALUE;
+	unsigned char *d = dst;
+	const int *c = src;
+
+	d[0] = cm[c[0] >> scalebits];
+	d[2] = cm[c[1] >> scalebits];
+	d[4] = cm[c[2] >> scalebits];
+	d[6] = cm[c[3] >> scalebits];
+
+	d = dst + bytes_per_line;
+	d[1] = cm[c[4] >> scalebits];
+	d[3] = cm[c[5] >> scalebits];
+	d[5] = cm[c[6] >> scalebits];
+	d[7] = cm[c[7] >> scalebits];
+
+	d = dst + bytes_per_line*2;
+	d[0] = cm[c[8] >> scalebits];
+	d[2] = cm[c[9] >> scalebits];
+	d[4] = cm[c[10] >> scalebits];
+	d[6] = cm[c[11] >> scalebits];
+
+	d = dst + bytes_per_line*3;
+	d[1] = cm[c[12] >> scalebits];
+	d[3] = cm[c[13] >> scalebits];
+	d[5] = cm[c[14] >> scalebits];
+	d[7] = cm[c[15] >> scalebits];
+#else
+	int i;
+	unsigned char *d;
+	const int *c = src;
+
+	d = dst;
+	for (i = 0; i < 4; i++, c++)
+		d[i*2] = CLAMP((*c) >> scalebits);
+
+	d = dst + bytes_per_line;
+	for (i = 0; i < 4; i++, c++)
+		d[i*2+1] = CLAMP((*c) >> scalebits);
+
+	d = dst + bytes_per_line*2;
+	for (i = 0; i < 4; i++, c++)
+		d[i*2] = CLAMP((*c) >> scalebits);
+
+	d = dst + bytes_per_line*3;
+	for (i = 0; i < 4; i++, c++)
+		d[i*2+1] = CLAMP((*c) >> scalebits);
+#endif
+}
+#endif
+
+/*
+ * To manage the stream, we keep bits in a 32 bits register.
+ * fill_nbits(n): fill the reservoir with at least n bits
+ * skip_bits(n): discard n bits from the reservoir
+ * get_bits(n): fill the reservoir, returns the first n bits and discard the
+ *              bits from the reservoir.
+ * __get_nbits(n): faster version of get_bits(n), but asumes that the reservoir
+ *                 contains at least n bits. bits returned is discarded.
+ */
+#define fill_nbits(pdec, nbits_wanted) do { \
+   while (pdec->nbits_in_reservoir<(nbits_wanted)) \
+    { \
+      pdec->reservoir |= (*(pdec->stream)++) << (pdec->nbits_in_reservoir); \
+      pdec->nbits_in_reservoir += 8; \
+    } \
+}  while(0);
+
+#define skip_nbits(pdec, nbits_to_skip) do { \
+   pdec->reservoir >>= (nbits_to_skip); \
+   pdec->nbits_in_reservoir -= (nbits_to_skip); \
+}  while(0);
+
+#define get_nbits(pdec, nbits_wanted, result) do { \
+   fill_nbits(pdec, nbits_wanted); \
+   result = (pdec->reservoir) & ((1U<<(nbits_wanted))-1); \
+   skip_nbits(pdec, nbits_wanted); \
+}  while(0);
+
+#define __get_nbits(pdec, nbits_wanted, result) do { \
+   result = (pdec->reservoir) & ((1U<<(nbits_wanted))-1); \
+   skip_nbits(pdec, nbits_wanted); \
+}  while(0);
+
+#define look_nbits(pdec, nbits_wanted) \
+   ((pdec->reservoir) & ((1U<<(nbits_wanted))-1))
+
+/*
+ * Decode a 4x4 pixel block
+ */
+static void decode_block(struct pwc_dec23_private *pdec,
+			 const unsigned char *ptable0004,
+			 const unsigned char *ptable8004)
+{
+	unsigned int primary_color;
+	unsigned int channel_v, offset1, op;
+	int i;
+
+	fill_nbits(pdec, 16);
+	__get_nbits(pdec, pdec->nbits, primary_color);
+
+	if (look_nbits(pdec,2) == 0) {
+		skip_nbits(pdec, 2);
+		/* Very simple, the color is the same for all pixels of the square */
+		for (i = 0; i < 16; i++)
+			pdec->temp_colors[i] = pdec->table_dc00[primary_color];
+
+		return;
+	}
+
+	/* This block is encoded with small pattern */
+	for (i = 0; i < 16; i++)
+		pdec->temp_colors[i] = pdec->table_d800[primary_color];
+
+	__get_nbits(pdec, 3, channel_v);
+	channel_v = ((channel_v & 1) << 2) | (channel_v & 2) | ((channel_v & 4) >> 2);
+
+	ptable0004 += (channel_v * 128);
+	ptable8004 += (channel_v * 32);
+
+	offset1 = 0;
+	do
+	{
+		unsigned int htable_idx, rows = 0;
+		const unsigned int *block;
+
+		/* [  zzzz y x x ]
+		 *     xx == 00 :=> end of the block def, remove the two bits from the stream
+		 *    yxx == 111
+		 *    yxx == any other value
+		 *
+		 */
+		fill_nbits(pdec, 16);
+		htable_idx = look_nbits(pdec, 6);
+		op = hash_table_ops[htable_idx * 4];
+
+		if (op == 2) {
+			skip_nbits(pdec, 2);
+
+		} else if (op == 1) {
+			/* 15bits [ xxxx xxxx yyyy 111 ]
+			 * yyy => offset in the table8004
+			 * xxx => offset in the tabled004 (tree)
+			 */
+			unsigned int mask, shift;
+			unsigned int nbits, col1;
+			unsigned int yyyy;
+
+			skip_nbits(pdec, 3);
+			/* offset1 += yyyy */
+			__get_nbits(pdec, 4, yyyy);
+			offset1 += 1 + yyyy;
+			offset1 &= 0x0F;
+			nbits = ptable8004[offset1 * 2];
+
+			/* col1 = xxxx xxxx */
+			__get_nbits(pdec, nbits+1, col1);
+
+			/* Bit mask table */
+			mask = pdec->table_bitpowermask[nbits][col1];
+			shift = ptable8004[offset1 * 2 + 1];
+			rows = ((mask << shift) + 0x80) & 0xFF;
+
+			block = pdec->table_subblock[rows];
+			for (i = 0; i < 16; i++)
+				pdec->temp_colors[i] += block[MulIdx[offset1][i]];
+
+		} else {
+			/* op == 0
+			 * offset1 is coded on 3 bits
+			 */
+			unsigned int shift;
+
+			offset1 += hash_table_ops [htable_idx * 4 + 2];
+			offset1 &= 0x0F;
+
+			rows = ptable0004[offset1 + hash_table_ops [htable_idx * 4 + 3]];
+			block = pdec->table_subblock[rows];
+			for (i = 0; i < 16; i++)
+				pdec->temp_colors[i] += block[MulIdx[offset1][i]];
+
+			shift = hash_table_ops[htable_idx * 4 + 1];
+			skip_nbits(pdec, shift);
+		}
+
+	} while (op != 2);
+
+}
+
+static void DecompressBand23(struct pwc_dec23_private *pdec,
+			     const unsigned char *rawyuv,
+			     unsigned char *planar_y,
+			     unsigned char *planar_u,
+			     unsigned char *planar_v,
+			     unsigned int   compressed_image_width,
+			     unsigned int   real_image_width)
+{
+	int compression_index, nblocks;
+	const unsigned char *ptable0004;
+	const unsigned char *ptable8004;
+
+	pdec->reservoir = 0;
+	pdec->nbits_in_reservoir = 0;
+	pdec->stream = rawyuv + 1;	/* The first byte of the stream is skipped */
+
+	get_nbits(pdec, 4, compression_index);
+
+	/* pass 1: uncompress Y component */
+	nblocks = compressed_image_width / 4;
+
+	ptable0004 = pdec->table_0004_pass1[compression_index];
+	ptable8004 = pdec->table_8004_pass1[compression_index];
+
+	/* Each block decode a square of 4x4 */
+	while (nblocks) {
+		decode_block(pdec, ptable0004, ptable8004);
+		copy_image_block_Y(pdec->temp_colors, planar_y, real_image_width, pdec->scalebits);
+		planar_y += 4;
+		nblocks--;
+	}
+
+	/* pass 2: uncompress UV component */
+	nblocks = compressed_image_width / 8;
+
+	ptable0004 = pdec->table_0004_pass2[compression_index];
+	ptable8004 = pdec->table_8004_pass2[compression_index];
+
+	/* Each block decode a square of 4x4 */
+	while (nblocks) {
+		decode_block(pdec, ptable0004, ptable8004);
+		copy_image_block_CrCb(pdec->temp_colors, planar_u, real_image_width/2, pdec->scalebits);
+
+		decode_block(pdec, ptable0004, ptable8004);
+		copy_image_block_CrCb(pdec->temp_colors, planar_v, real_image_width/2, pdec->scalebits);
+
+		planar_v += 8;
+		planar_u += 8;
+		nblocks -= 2;
+	}
+
+}
+
+#if ENABLE_BAYER_DECODER
+/*
+ * Size need to be a multiple of 8 in width
+ *
+ * Return a block of four line encoded like this:
+ *
+ *   G R G R G R G R G R G R G R G R
+ *   B G B G B G B G B G B G B G B G
+ *   G R G R G R G R G R G R G R G R
+ *   B G B G B G B G B G B G B G B G
+ *
+ */
+static void DecompressBandBayer(struct pwc_dec23_private *pdec,
+    				const unsigned char *rawyuv,
+				unsigned char *rgbbayer,
+				unsigned int   compressed_image_width,
+				unsigned int   real_image_width)
+{
+	int compression_index, nblocks;
+	const unsigned char *ptable0004;
+	const unsigned char *ptable8004;
+	unsigned char *dest;
+
+	pdec->reservoir = 0;
+	pdec->nbits_in_reservoir = 0;
+	pdec->stream = rawyuv + 1;	/* The first byte of the stream is skipped */
+
+	get_nbits(pdec, 4, compression_index);
+
+	/* pass 1: uncompress RB component */
+	nblocks = compressed_image_width / 4;
+
+	ptable0004 = pdec->table_0004_pass1[compression_index];
+	ptable8004 = pdec->table_8004_pass1[compression_index];
+	dest = rgbbayer;
+
+	/* Each block decode a square of 4x4 */
+	while (nblocks) {
+		decode_block(pdec, ptable0004, ptable8004);
+		copy_image_block_RedBlue(pdec->temp_colors, rgbbayer, real_image_width, pdec->scalebits);
+		dest += 8;
+		nblocks--;
+	}
+
+	/* pass 2: uncompress G component */
+	nblocks = compressed_image_width / 8;
+
+	ptable0004 = pdec->table_0004_pass2[compression_index];
+	ptable8004 = pdec->table_8004_pass2[compression_index];
+
+	/* Each block decode a square of 4x4 */
+	while (nblocks) {
+		decode_block(pdec, ptable0004, ptable8004);
+		copy_image_block_Green(pdec->temp_colors, rgbbayer+1, real_image_width, pdec->scalebits);
+
+		decode_block(pdec, ptable0004, ptable8004);
+		copy_image_block_Green(pdec->temp_colors, rgbbayer+real_image_width, real_image_width, pdec->scalebits);
+
+		rgbbayer += 16;
+		nblocks -= 2;
+	}
+}
+#endif
+
+
+/**
+ *
+ * Uncompress a pwc23 buffer.
+ *
+ * pwc.view: size of the image wanted
+ * pwc.image: size of the image returned by the camera
+ * pwc.offset: (x,y) to displayer image in the view
+ *
+ * src: raw data
+ * dst: image output
+ * flags: PWCX_FLAG_PLANAR or PWCX_FLAG_BAYER
+ */
+void pwc_dec23_decompress(const struct pwc_device *pwc,
+			  const void *src,
+			  void *dst,
+			  int flags)
+{
+	int bandlines_left, stride, bytes_per_block;
+
+	bandlines_left = pwc->image.y / 4;
+	bytes_per_block = pwc->view.x * 4;
+
+	if (flags & PWCX_FLAG_BAYER) {
+#if ENABLE_BAYER_DECODER
+		/* RGB Bayer format */
+		unsigned char *rgbout;
+
+		stride = pwc->view.x * pwc->offset.y;
+		rgbout = dst + stride + pwc->offset.x;
+
+
+		while (bandlines_left--) {
+
+			DecompressBandBayer(pwc->decompress_data,
+					    src,
+					    rgbout,
+					    pwc->image.x, pwc->view.x);
+
+			src += pwc->vbandlength;
+			rgbout += bytes_per_block;
+
+		}
+#else
+		memcpy(dst, 0, pwc->view.x * pwc->view.y);
+#endif
+
+	} else {
+		/* YUV420P image format */
+		unsigned char *pout_planar_y;
+		unsigned char *pout_planar_u;
+		unsigned char *pout_planar_v;
+		unsigned int   plane_size;
+
+		plane_size = pwc->view.x * pwc->view.y;
+
+		/* offset in Y plane */
+		stride = pwc->view.x * pwc->offset.y;
+		pout_planar_y = dst + stride + pwc->offset.x;
+
+		/* offsets in U/V planes */
+		stride = (pwc->view.x * pwc->offset.y) / 4 + pwc->offset.x / 2;
+		pout_planar_u = dst + plane_size + stride;
+		pout_planar_v = dst + plane_size + plane_size / 4 + stride;
+
+		while (bandlines_left--) {
+
+			DecompressBand23(pwc->decompress_data,
+					 src,
+					 pout_planar_y, pout_planar_u, pout_planar_v,
+					 pwc->image.x, pwc->view.x);
+			src += pwc->vbandlength;
+			pout_planar_y += bytes_per_block;
+			pout_planar_u += pwc->view.x;
+			pout_planar_v += pwc->view.x;
+
+		}
+
+	}
+
+}
+
+void pwc_dec23_exit(void)
+{
+	/* Do nothing */
+
+}
+
+/**
+ * Allocate a private structure used by lookup table.
+ * You must call kfree() to free the memory allocated.
+ */
+int pwc_dec23_alloc(struct pwc_device *pwc)
+{
+	pwc->decompress_data = kmalloc(sizeof(struct pwc_dec23_private), GFP_KERNEL);
+	if (pwc->decompress_data == NULL)
+		return -ENOMEM;
+	return 0;
+}
+
+/* vim: set cino= formatoptions=croql cindent shiftwidth=8 tabstop=8: */