diff mbox

libv4lconvert support for SQ905C decompression (revised)

Message ID alpine.LNX.2.00.0903041730550.23054@banach.math.auburn.edu (mailing list archive)
State RFC
Headers show

Commit Message

kilgota@banach.math.auburn.edu March 4, 2009, 11:37 p.m. UTC
Hans,

From an abundance of caution, I thought I had better run the v4lconvert 
patch which supports the SQ905C compressed format through the 
checkpatch.pl process, too. The result of that process appears here, 
below the signed-off-by line.

Theodore Kilgore

---------- Forwarded message ----------
Date: Sun, 1 Mar 2009 17:45:32 -0600 (CST)
From: kilgota@banach.math.auburn.edu
To: Hans de Goede <hdegoede@redhat.com>, linux-media@vger.kernel.org
Subject: [PATCH] libv4lconvert support for SQ905C decompression

Hans,

Below is a patch for libv4lconvert, to support the decompression used by the 
SQ905C cameras (0x2770:0x905C) and some other related cameras. There is at the 
moment no support module for these cameras in streaming mode, but I intend to 
submit one.

This contribution was created in whole by me, based upon code in libgphoto2 
which was created in whole by me, and which was licensed for
libgphoto2 under the LGPL license.

Signed-off-by: Theodore Kilgore <kilgota@auburn.edu>

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Comments

Hans de Goede March 11, 2009, 1:24 p.m. UTC | #1
kilgota@banach.math.auburn.edu wrote:
> 
> Hans,
> 
>  From an abundance of caution, I thought I had better run the v4lconvert 
> patch which supports the SQ905C compressed format through the 
> checkpatch.pl process, too. The result of that process appears here, 
> below the signed-off-by line.
> 
> Theodore Kilgore
> 

Thanks applied to me tree:
http://linuxtv.org/hg/~hgoede/libv4l

I expect to release libv4l-0.5.9 with this in, soon.

Regards,

Hans

> ---------- Forwarded message ----------
> Date: Sun, 1 Mar 2009 17:45:32 -0600 (CST)
> From: kilgota@banach.math.auburn.edu
> To: Hans de Goede <hdegoede@redhat.com>, linux-media@vger.kernel.org
> Subject: [PATCH] libv4lconvert support for SQ905C decompression
> 
> Hans,
> 
> Below is a patch for libv4lconvert, to support the decompression used by 
> the SQ905C cameras (0x2770:0x905C) and some other related cameras. There 
> is at the moment no support module for these cameras in streaming mode, 
> but I intend to submit one.
> 
> This contribution was created in whole by me, based upon code in 
> libgphoto2 which was created in whole by me, and which was licensed for
> libgphoto2 under the LGPL license.
> 
> Signed-off-by: Theodore Kilgore <kilgota@auburn.edu>
> 
> -----------------------------------------------------------------------
> diff -uprN libv4lconvert-old/Makefile libv4lconvert-new/Makefile
> --- libv4lconvert-old/Makefile    2009-03-01 15:37:38.000000000 -0600
> +++ libv4lconvert-new/Makefile    2009-03-04 16:22:52.000000000 -0600
> @@ -12,7 +12,7 @@ endif
> 
>  CONVERT_OBJS  = libv4lconvert.o tinyjpeg.o sn9c10x.o sn9c20x.o pac207.o \
>          mr97310a.o flip.o crop.o jidctflt.o spca561-decompress.o \
> -        rgbyuv.o spca501.o bayer.o
> +        rgbyuv.o spca501.o sq905c.o bayer.o
>  TARGETS       = $(CONVERT_LIB) libv4lconvert.pc
>  INCLUDES      = ../include/libv4lconvert.h
> 
> diff -uprN libv4lconvert-old/libv4lconvert-priv.h 
> libv4lconvert-new/libv4lconvert-priv.h
> --- libv4lconvert-old/libv4lconvert-priv.h    2009-03-01 
> 15:37:38.000000000 -0600
> +++ libv4lconvert-new/libv4lconvert-priv.h    2009-03-04 
> 16:22:52.000000000 -0600
> @@ -47,6 +47,10 @@
>  #define V4L2_PIX_FMT_MR97310A v4l2_fourcc('M','3','1','0')
>  #endif
> 
> +#ifndef V4L2_PIX_FMT_SQ905C
> +#define V4L2_PIX_FMT_SQ905C v4l2_fourcc('9', '0', '5', 'C')
> +#endif
> +
>  #ifndef V4L2_PIX_FMT_PJPG
>  #define V4L2_PIX_FMT_PJPG v4l2_fourcc('P', 'J', 'P', 'G')
>  #endif
> @@ -180,6 +184,9 @@ void v4lconvert_decode_pac207(const unsi
>  void v4lconvert_decode_mr97310a(const unsigned char *src, unsigned char 
> *dst,
>    int width, int height);
> 
> +void v4lconvert_decode_sq905c(const unsigned char *src, unsigned char 
> *dst,
> +  int width, int height);
> +
>  void v4lconvert_bayer_to_rgb24(const unsigned char *bayer,
>    unsigned char *rgb, int width, int height, unsigned int pixfmt);
> 
> diff -uprN libv4lconvert-old/libv4lconvert.c 
> libv4lconvert-new/libv4lconvert.c
> --- libv4lconvert-old/libv4lconvert.c    2009-03-01 15:37:38.000000000 
> -0600
> +++ libv4lconvert-new/libv4lconvert.c    2009-03-04 16:22:52.000000000 
> -0600
> @@ -61,6 +61,7 @@ static const struct v4lconvert_pixfmt su
>    { V4L2_PIX_FMT_SN9C10X,      V4LCONVERT_COMPRESSED },
>    { V4L2_PIX_FMT_PAC207,       V4LCONVERT_COMPRESSED },
>    { V4L2_PIX_FMT_MR97310A,     V4LCONVERT_COMPRESSED },
> +  { V4L2_PIX_FMT_SQ905C,       V4LCONVERT_COMPRESSED },
>    { V4L2_PIX_FMT_PJPG,         V4LCONVERT_COMPRESSED },
>  };
> 
> @@ -608,6 +609,7 @@ static int v4lconvert_convert_pixfmt(str
>      case V4L2_PIX_FMT_SN9C10X:
>      case V4L2_PIX_FMT_PAC207:
>      case V4L2_PIX_FMT_MR97310A:
> +    case V4L2_PIX_FMT_SQ905C:
>      {
>        unsigned char *tmpbuf;
> 
> @@ -633,6 +635,10 @@ static int v4lconvert_convert_pixfmt(str
>        v4lconvert_decode_mr97310a(src, tmpbuf, width, height);
>        src_pix_fmt = V4L2_PIX_FMT_SBGGR8;
>        break;
> +    case V4L2_PIX_FMT_SQ905C:
> +      v4lconvert_decode_sq905c(src, tmpbuf, width, height);
> +      src_pix_fmt = V4L2_PIX_FMT_SRGGB8;
> +      break;
>        }
>        src = tmpbuf;
>        /* Deliberate fall through to raw bayer fmt code! */
> diff -uprN libv4lconvert-old/sq905c.c libv4lconvert-new/sq905c.c
> --- libv4lconvert-old/sq905c.c    1969-12-31 18:00:00.000000000 -0600
> +++ libv4lconvert-new/sq905c.c    2009-03-04 16:27:17.000000000 -0600
> @@ -0,0 +1,217 @@
> +/*
> + * sq905c.c
> + *
> + * Here is the decompression function for the SQ905C cameras. The 
> functions
> + * used are adapted from the libgphoto2 functions for the same cameras,
> + * which was
> + * Copyright (c) 2005 and 2007 Theodore Kilgore <kilgota@auburn.edu>
> + * This version for libv4lconvert is
> + * Copyright (c) 2009 Theodore Kilgore <kilgota@auburn.edu>
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU Lesser General Public License as 
> published by
> + * the Free Software Foundation; either version 2.1 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 Lesser General Public License for more details.
> + *
> + * You should have received a copy of the GNU Lesser 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 <stdlib.h>
> +
> +#include "libv4lconvert-priv.h"
> +
> +
> +#define CLIP(x) ((x) < 0 ? 0 : ((x) > 0xff) ? 0xff : (x))
> +
> +
> +static int
> +sq905c_first_decompress(unsigned char *output, unsigned char *input,
> +                        unsigned int outputsize)
> +{
> +    unsigned char parity = 0;
> +    unsigned char nibble_to_keep[2];
> +    unsigned char temp1 = 0, temp2 = 0;
> +    unsigned char input_byte;
> +    unsigned char lookup = 0;
> +    unsigned int i = 0;
> +    unsigned int bytes_used = 0;
> +    unsigned int bytes_done = 0;
> +    unsigned int bit_counter = 8;
> +    unsigned int cycles = 0;
> +    int table[9] = { -1, 0, 2, 6, 0x0e, 0x0e, 0x0e, 0x0e, 0xfb};
> +    unsigned char lookup_table[16]
> +             = {0, 2, 6, 0x0e, 0xf0, 0xf1, 0xf2, 0xf3, 0xf4,
> +            0xf5, 0xf6, 0xf7, 0xf8, 0xf9, 0xfa, 0xfb};
> +    unsigned char translator[16] = {8, 7, 9, 6, 10, 11, 12, 13,
> +                    14, 15, 5, 4, 3, 2, 1, 0};
> +
> +    nibble_to_keep[0] = 0;
> +    nibble_to_keep[1] = 0;
> +
> +    while (bytes_done < outputsize) {
> +        while (parity < 2) {
> +            while (lookup > table[cycles]) {
> +                if (bit_counter == 8) {
> +                    input_byte = input[bytes_used];
> +                    bytes_used++;
> +                    temp1 = input_byte;
> +                    bit_counter = 0;
> +                }
> +                input_byte = temp1;
> +                temp2 = (temp2 << 1) & 0xFF;
> +                input_byte = input_byte >> 7;
> +                temp2 = temp2 | input_byte;
> +                temp1 = (temp1 << 1) & 0xFF;
> +                bit_counter++;
> +                cycles++;
> +                if (cycles > 9)
> +                    return -1;
> +                lookup = temp2 & 0xff;
> +            }
> +            temp2 = 0;
> +            for (i = 0; i < 17; i++) {
> +                if (lookup == lookup_table[i]) {
> +                    nibble_to_keep[parity] = translator[i];
> +                    break;
> +                }
> +                if (i == 16)
> +                    return -1;
> +            }
> +            cycles = 0;
> +            parity++;
> +        }
> +        output[bytes_done] = (nibble_to_keep[0]<<4)|nibble_to_keep[1];
> +        bytes_done++;
> +        parity = 0;
> +    }
> +    return 0;
> +}
> +
> +static int
> +sq905c_second_decompress(unsigned char *uncomp, unsigned char *in,
> +                            int width, int height)
> +{
> +    int diff = 0;
> +    int tempval = 0;
> +    int i, m, parity;
> +    unsigned char delta_left = 0;
> +    unsigned char delta_right = 0;
> +    int input_counter = 0;
> +    int delta_table[] = {-144, -110, -77, -53, -35, -21, -11, -3,
> +                2, 10, 20, 34, 52, 76, 110, 144};
> +    unsigned char *templine_red;
> +    unsigned char *templine_green;
> +    unsigned char *templine_blue;
> +    templine_red = malloc(width);
> +    if (!templine_red) {
> +        free(templine_red);
> +        return -1;
> +    }
> +    for (i = 0; i < width; i++)
> +        templine_red[i] = 0x80;
> +    templine_green = malloc(width);
> +    if (!templine_green) {
> +        free(templine_green);
> +        return -1;
> +    }
> +    for (i = 0; i < width; i++)
> +        templine_green[i] = 0x80;
> +    templine_blue = malloc(width);
> +    if (!templine_blue) {
> +        free(templine_blue);
> +        return -1;
> +    }
> +    for (i = 0; i < width; i++)
> +        templine_blue[i] = 0x80;
> +    for (m = 0; m < height/2; m++) {
> +        /* First we do an even-numbered line */
> +        for (i = 0; i < width/2; i++) {
> +            parity = i&1;
> +            delta_right = in[input_counter] & 0x0f;
> +            delta_left = (in[input_counter]>>4)&0xff;
> +            input_counter++;
> +            /* left pixel (red) */
> +            diff = delta_table[delta_left];
> +            if (!i)
> +                tempval = templine_red[0] + diff;
> +            else
> +                tempval = (templine_red[i]
> +                    + uncomp[2*m*width+2*i-2])/2 + diff;
> +            tempval = CLIP(tempval);
> +            uncomp[2*m*width+2*i] = tempval;
> +            templine_red[i] = tempval;
> +            /* right pixel (green) */
> +            diff = delta_table[delta_right];
> +            if (!i)
> +                tempval = templine_green[1] + diff;
> +            else if (2*i == width - 2)
> +                tempval = (templine_green[i]
> +                        + uncomp[2*m*width+2*i-1])/2
> +                            + diff;
> +            else
> +                tempval = (templine_green[i+1]
> +                        + uncomp[2*m*width+2*i-1])/2
> +                            + diff;
> +            tempval = CLIP(tempval);
> +            uncomp[2*m*width+2*i+1] = tempval;
> +            templine_green[i] = tempval;
> +        }
> +        /* then an odd-numbered line */
> +        for (i = 0; i < width/2; i++) {
> +            delta_right = in[input_counter] & 0x0f;
> +            delta_left = (in[input_counter]>>4) & 0xff;
> +            input_counter++;
> +            /* left pixel (green) */
> +            diff = delta_table[delta_left];
> +            if (!i)
> +                tempval = templine_green[0] + diff;
> +            else
> +                tempval = (templine_green[i]
> +                    + uncomp[(2*m+1)*width+2*i-2])/2
> +                        + diff;
> +            tempval = CLIP(tempval);
> +            uncomp[(2*m+1)*width+2*i] = tempval;
> +            templine_green[i] = tempval;
> +            /* right pixel (blue) */
> +            diff = delta_table[delta_right];
> +            if (!i)
> +                tempval = templine_blue[0] + diff;
> +            else
> +                tempval = (templine_blue[i]
> +                        + uncomp[(2*m+1)*width+2*i-1])/2
> +                        + diff;
> +            tempval = CLIP(tempval);
> +            uncomp[(2*m+1)*width+2*i+1] = tempval;
> +            templine_blue[i] = tempval;
> +        }
> +    }
> +    free(templine_green);
> +    free(templine_red);
> +    free(templine_blue);
> +    return 0;
> +}
> +
> +void v4lconvert_decode_sq905c(const unsigned char *src, unsigned char 
> *dst,
> +  int width, int height)
> +{
> +    int size;
> +    unsigned char *temp_data;
> +    unsigned char *raw;
> +    /* here we get rid of the 0x50 bytes of header in src. */
> +    raw = src + 0x50;
> +    size = width*height/2;
> +    temp_data = malloc(size);
> +    if (!temp_data)
> +        goto out;
> +    sq905c_first_decompress(temp_data, raw, size);
> +    sq905c_second_decompress(dst, temp_data, width, height);
> +out:
> +    free(temp_data);
> +}
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diff mbox

Patch

diff -uprN libv4lconvert-old/Makefile libv4lconvert-new/Makefile
--- libv4lconvert-old/Makefile	2009-03-01 15:37:38.000000000 -0600
+++ libv4lconvert-new/Makefile	2009-03-04 16:22:52.000000000 -0600
@@ -12,7 +12,7 @@  endif

  CONVERT_OBJS  = libv4lconvert.o tinyjpeg.o sn9c10x.o sn9c20x.o pac207.o \
  		mr97310a.o flip.o crop.o jidctflt.o spca561-decompress.o \
-		rgbyuv.o spca501.o bayer.o
+		rgbyuv.o spca501.o sq905c.o bayer.o
  TARGETS       = $(CONVERT_LIB) libv4lconvert.pc
  INCLUDES      = ../include/libv4lconvert.h

diff -uprN libv4lconvert-old/libv4lconvert-priv.h libv4lconvert-new/libv4lconvert-priv.h
--- libv4lconvert-old/libv4lconvert-priv.h	2009-03-01 15:37:38.000000000 -0600
+++ libv4lconvert-new/libv4lconvert-priv.h	2009-03-04 16:22:52.000000000 -0600
@@ -47,6 +47,10 @@ 
  #define V4L2_PIX_FMT_MR97310A v4l2_fourcc('M','3','1','0')
  #endif

+#ifndef V4L2_PIX_FMT_SQ905C
+#define V4L2_PIX_FMT_SQ905C v4l2_fourcc('9', '0', '5', 'C')
+#endif
+
  #ifndef V4L2_PIX_FMT_PJPG
  #define V4L2_PIX_FMT_PJPG v4l2_fourcc('P', 'J', 'P', 'G')
  #endif
@@ -180,6 +184,9 @@  void v4lconvert_decode_pac207(const unsi
  void v4lconvert_decode_mr97310a(const unsigned char *src, unsigned char *dst,
    int width, int height);

+void v4lconvert_decode_sq905c(const unsigned char *src, unsigned char *dst,
+  int width, int height);
+
  void v4lconvert_bayer_to_rgb24(const unsigned char *bayer,
    unsigned char *rgb, int width, int height, unsigned int pixfmt);

diff -uprN libv4lconvert-old/libv4lconvert.c libv4lconvert-new/libv4lconvert.c
--- libv4lconvert-old/libv4lconvert.c	2009-03-01 15:37:38.000000000 -0600
+++ libv4lconvert-new/libv4lconvert.c	2009-03-04 16:22:52.000000000 -0600
@@ -61,6 +61,7 @@  static const struct v4lconvert_pixfmt su
    { V4L2_PIX_FMT_SN9C10X,      V4LCONVERT_COMPRESSED },
    { V4L2_PIX_FMT_PAC207,       V4LCONVERT_COMPRESSED },
    { V4L2_PIX_FMT_MR97310A,     V4LCONVERT_COMPRESSED },
+  { V4L2_PIX_FMT_SQ905C,       V4LCONVERT_COMPRESSED },
    { V4L2_PIX_FMT_PJPG,         V4LCONVERT_COMPRESSED },
  };

@@ -608,6 +609,7 @@  static int v4lconvert_convert_pixfmt(str
      case V4L2_PIX_FMT_SN9C10X:
      case V4L2_PIX_FMT_PAC207:
      case V4L2_PIX_FMT_MR97310A:
+    case V4L2_PIX_FMT_SQ905C:
      {
        unsigned char *tmpbuf;

@@ -633,6 +635,10 @@  static int v4lconvert_convert_pixfmt(str
  	  v4lconvert_decode_mr97310a(src, tmpbuf, width, height);
  	  src_pix_fmt = V4L2_PIX_FMT_SBGGR8;
  	  break;
+	case V4L2_PIX_FMT_SQ905C:
+	  v4lconvert_decode_sq905c(src, tmpbuf, width, height);
+	  src_pix_fmt = V4L2_PIX_FMT_SRGGB8;
+	  break;
        }
        src = tmpbuf;
        /* Deliberate fall through to raw bayer fmt code! */
diff -uprN libv4lconvert-old/sq905c.c libv4lconvert-new/sq905c.c
--- libv4lconvert-old/sq905c.c	1969-12-31 18:00:00.000000000 -0600
+++ libv4lconvert-new/sq905c.c	2009-03-04 16:27:17.000000000 -0600
@@ -0,0 +1,217 @@ 
+/*
+ * sq905c.c
+ *
+ * Here is the decompression function for the SQ905C cameras. The functions
+ * used are adapted from the libgphoto2 functions for the same cameras,
+ * which was
+ * Copyright (c) 2005 and 2007 Theodore Kilgore <kilgota@auburn.edu>
+ * This version for libv4lconvert is
+ * Copyright (c) 2009 Theodore Kilgore <kilgota@auburn.edu>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation; either version 2.1 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 Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser 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 <stdlib.h>
+
+#include "libv4lconvert-priv.h"
+
+
+#define CLIP(x) ((x) < 0 ? 0 : ((x) > 0xff) ? 0xff : (x))
+
+
+static int
+sq905c_first_decompress(unsigned char *output, unsigned char *input,
+					    unsigned int outputsize)
+{
+	unsigned char parity = 0;
+	unsigned char nibble_to_keep[2];
+	unsigned char temp1 = 0, temp2 = 0;
+	unsigned char input_byte;
+	unsigned char lookup = 0;
+	unsigned int i = 0;
+	unsigned int bytes_used = 0;
+	unsigned int bytes_done = 0;
+	unsigned int bit_counter = 8;
+	unsigned int cycles = 0;
+	int table[9] = { -1, 0, 2, 6, 0x0e, 0x0e, 0x0e, 0x0e, 0xfb};
+	unsigned char lookup_table[16]
+		     = {0, 2, 6, 0x0e, 0xf0, 0xf1, 0xf2, 0xf3, 0xf4,
+			0xf5, 0xf6, 0xf7, 0xf8, 0xf9, 0xfa, 0xfb};
+	unsigned char translator[16] = {8, 7, 9, 6, 10, 11, 12, 13,
+					14, 15, 5, 4, 3, 2, 1, 0};
+
+	nibble_to_keep[0] = 0;
+	nibble_to_keep[1] = 0;
+
+	while (bytes_done < outputsize) {
+		while (parity < 2) {
+			while (lookup > table[cycles]) {
+				if (bit_counter == 8) {
+					input_byte = input[bytes_used];
+					bytes_used++;
+					temp1 = input_byte;
+					bit_counter = 0;
+				}
+				input_byte = temp1;
+				temp2 = (temp2 << 1) & 0xFF;
+				input_byte = input_byte >> 7;
+				temp2 = temp2 | input_byte;
+				temp1 = (temp1 << 1) & 0xFF;
+				bit_counter++;
+				cycles++;
+				if (cycles > 9)
+					return -1;
+				lookup = temp2 & 0xff;
+			}
+			temp2 = 0;
+			for (i = 0; i < 17; i++) {
+				if (lookup == lookup_table[i]) {
+					nibble_to_keep[parity] = translator[i];
+					break;
+				}
+				if (i == 16)
+					return -1;
+			}
+			cycles = 0;
+			parity++;
+		}
+		output[bytes_done] = (nibble_to_keep[0]<<4)|nibble_to_keep[1];
+		bytes_done++;
+		parity = 0;
+	}
+	return 0;
+}
+
+static int
+sq905c_second_decompress(unsigned char *uncomp, unsigned char *in,
+						    int width, int height)
+{
+	int diff = 0;
+	int tempval = 0;
+	int i, m, parity;
+	unsigned char delta_left = 0;
+	unsigned char delta_right = 0;
+	int input_counter = 0;
+	int delta_table[] = {-144, -110, -77, -53, -35, -21, -11, -3,
+				2, 10, 20, 34, 52, 76, 110, 144};
+	unsigned char *templine_red;
+	unsigned char *templine_green;
+	unsigned char *templine_blue;
+	templine_red = malloc(width);
+	if (!templine_red) {
+		free(templine_red);
+		return -1;
+	}
+	for (i = 0; i < width; i++)
+		templine_red[i] = 0x80;
+	templine_green = malloc(width);
+	if (!templine_green) {
+		free(templine_green);
+		return -1;
+	}
+	for (i = 0; i < width; i++)
+		templine_green[i] = 0x80;
+	templine_blue = malloc(width);
+	if (!templine_blue) {
+		free(templine_blue);
+		return -1;
+	}
+	for (i = 0; i < width; i++)
+		templine_blue[i] = 0x80;
+	for (m = 0; m < height/2; m++) {
+		/* First we do an even-numbered line */
+		for (i = 0; i < width/2; i++) {
+			parity = i&1;
+			delta_right = in[input_counter] & 0x0f;
+			delta_left = (in[input_counter]>>4)&0xff;
+			input_counter++;
+			/* left pixel (red) */
+			diff = delta_table[delta_left];
+			if (!i)
+				tempval = templine_red[0] + diff;
+			else
+				tempval = (templine_red[i]
+					+ uncomp[2*m*width+2*i-2])/2 + diff;
+			tempval = CLIP(tempval);
+			uncomp[2*m*width+2*i] = tempval;
+			templine_red[i] = tempval;
+			/* right pixel (green) */
+			diff = delta_table[delta_right];
+			if (!i)
+				tempval = templine_green[1] + diff;
+			else if (2*i == width - 2)
+				tempval = (templine_green[i]
+						+ uncomp[2*m*width+2*i-1])/2
+							+ diff;
+			else
+				tempval = (templine_green[i+1]
+						+ uncomp[2*m*width+2*i-1])/2
+							+ diff;
+			tempval = CLIP(tempval);
+			uncomp[2*m*width+2*i+1] = tempval;
+			templine_green[i] = tempval;
+		}
+		/* then an odd-numbered line */
+		for (i = 0; i < width/2; i++) {
+			delta_right = in[input_counter] & 0x0f;
+			delta_left = (in[input_counter]>>4) & 0xff;
+			input_counter++;
+			/* left pixel (green) */
+			diff = delta_table[delta_left];
+			if (!i)
+				tempval = templine_green[0] + diff;
+			else
+				tempval = (templine_green[i]
+					+ uncomp[(2*m+1)*width+2*i-2])/2
+						+ diff;
+			tempval = CLIP(tempval);
+			uncomp[(2*m+1)*width+2*i] = tempval;
+			templine_green[i] = tempval;
+			/* right pixel (blue) */
+			diff = delta_table[delta_right];
+			if (!i)
+				tempval = templine_blue[0] + diff;
+			else
+				tempval = (templine_blue[i]
+					    + uncomp[(2*m+1)*width+2*i-1])/2
+						+ diff;
+			tempval = CLIP(tempval);
+			uncomp[(2*m+1)*width+2*i+1] = tempval;
+			templine_blue[i] = tempval;
+		}
+	}
+	free(templine_green);
+	free(templine_red);
+	free(templine_blue);
+	return 0;
+}
+
+void v4lconvert_decode_sq905c(const unsigned char *src, unsigned char *dst,
+  int width, int height)
+{
+	int size;
+	unsigned char *temp_data;
+	unsigned char *raw;
+	/* here we get rid of the 0x50 bytes of header in src. */
+	raw = src + 0x50;
+	size = width*height/2;
+	temp_data = malloc(size);
+	if (!temp_data)
+		goto out;
+	sq905c_first_decompress(temp_data, raw, size);
+	sq905c_second_decompress(dst, temp_data, width, height);
+out:
+	free(temp_data);
+}