drivers/usb/media/pwc/pwc-uncompress.c

   1 /* Linux driver for Philips webcam
   2    Decompression frontend.
   3    (C) 1999-2003 Nemosoft Unv.
   4    (C) 2004      Luc Saillard (luc@saillard.org)
   5
   6    NOTE: this version of pwc is an unofficial (modified) release of pwc & pcwx
   7    driver and thus may have bugs that are not present in the original version.
   8    Please send bug reports and support requests to <luc@saillard.org>.
   9    The decompression routines have been implemented by reverse-engineering the
  10    Nemosoft binary pwcx module. Caveat emptor.
  11
  12    This program is free software; you can redistribute it and/or modify
  13    it under the terms of the GNU General Public License as published by
  14    the Free Software Foundation; either version 2 of the License, or
  15    (at your option) any later version.
  16
  17    This program is distributed in the hope that it will be useful,
  18    but WITHOUT ANY WARRANTY; without even the implied warranty of
  19    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  20    GNU General Public License for more details.
  21
  22    You should have received a copy of the GNU General Public License
  23    along with this program; if not, write to the Free Software
  24    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  25 */
  26
  27 #include <asm/current.h>
  28 #include <asm/types.h>
  29
  30 #include "pwc.h"
  31 #include "pwc-uncompress.h"
  32 #include "pwc-dec1.h"
  33 #include "pwc-dec23.h"
  34
  35 int pwc_decompress(struct pwc_device *pdev)
  36 {
  37         struct pwc_frame_buf *fbuf;
  38         int n, line, col, stride;
  39         void *yuv, *image;
  40         u16 *src;
  41         u16 *dsty, *dstu, *dstv;
  42
  43         if (pdev == NULL)
  44                 return -EFAULT;
  45 #if defined(__KERNEL__) && defined(PWC_MAGIC)
  46         if (pdev->magic != PWC_MAGIC) {
  47                 Err("pwc_decompress(): magic failed.\n");
  48                 return -EFAULT;
  49         }
  50 #endif
  51
  52         fbuf = pdev->read_frame;
  53         if (fbuf == NULL)
  54                 return -EFAULT;
  55         image = pdev->image_ptr[pdev->fill_image];
  56         if (!image)
  57                 return -EFAULT;
  58
  59         yuv = fbuf->data + pdev->frame_header_size;  /* Skip header */
  60
  61         /* Raw format; that's easy... */
  62         if (pdev->vpalette == VIDEO_PALETTE_RAW)
  63         {
  64                 memcpy(image, yuv, pdev->frame_size);
  65                 return 0;
  66         }
  67
  68         if (pdev->vbandlength == 0) {
  69                 /* Uncompressed mode. We copy the data into the output buffer,
  70                    using the viewport size (which may be larger than the image
  71                    size). Unfortunately we have to do a bit of byte stuffing
  72                    to get the desired output format/size.
  73                  */
  74                         /*
  75                          * We do some byte shuffling here to go from the
  76                          * native format to YUV420P.
  77                          */
  78                         src = (u16 *)yuv;
  79                         n = pdev->view.x * pdev->view.y;
  80
  81                         /* offset in Y plane */
  82                         stride = pdev->view.x * pdev->offset.y + pdev->offset.x;
  83                         dsty = (u16 *)(image + stride);
  84
  85                         /* offsets in U/V planes */
  86                         stride = pdev->view.x * pdev->offset.y / 4 + pdev->offset.x / 2;
  87                         dstu = (u16 *)(image + n +         stride);
  88                         dstv = (u16 *)(image + n + n / 4 + stride);
  89
  90                         /* increment after each line */
  91                         stride = (pdev->view.x - pdev->image.x) / 2; /* u16 is 2 bytes */
  92
  93                         for (line = 0; line < pdev->image.y; line++) {
  94                                 for (col = 0; col < pdev->image.x; col += 4) {
  95                                         *dsty++ = *src++;
  96                                         *dsty++ = *src++;
  97                                         if (line & 1)
  98                                                 *dstv++ = *src++;
  99                                         else
 100                                                 *dstu++ = *src++;
 101                                 }
 102                                 dsty += stride;
 103                                 if (line & 1)
 104                                         dstv += (stride >> 1);
 105                                 else
 106                                         dstu += (stride >> 1);
 107                         }
 108         }
 109         else {
 110                 /* Compressed; the decompressor routines will write the data
 111                    in planar format immediately.
 112                  */
 113                 int flags;
 114
 115                 flags = PWCX_FLAG_PLANAR;
 116                 if (pdev->vsize == PSZ_VGA && pdev->vframes == 5 && pdev->vsnapshot)
 117                  {
 118                    printk(KERN_ERR "pwc: Mode Bayer is not supported for now\n");
 119                    flags |= PWCX_FLAG_BAYER;
 120                    return -ENXIO; /* No such device or address: missing decompressor */
 121                  }
 122
 123                 switch (pdev->type)
 124                  {
 125                   case 675:
 126                   case 680:
 127                   case 690:
 128                   case 720:
 129                   case 730:
 130                   case 740:
 131                   case 750:
 132                     pwc_dec23_decompress(&pdev->image, &pdev->view, &pdev->offset,
 133                                 yuv, image,
 134                                 flags,
 135                                 pdev->decompress_data, pdev->vbandlength);
 136                     break;
 137                   case 645:
 138                   case 646:
 139                     /* TODO & FIXME */
 140                     return -ENXIO; /* No such device or address: missing decompressor */
 141                     break;
 142                  }
 143         }
 144         return 0;
 145 }
 146
 147