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

   1 /* Linux driver for Philips webcam
   2    Decompression frontend.
   3    (C) 1999-2003 Nemosoft Unv.
   4    (C) 2004-2006 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    vim: set ts=8:
  27 */
  28
  29 #include <asm/current.h>
  30 #include <asm/types.h>
  31
  32 #include "pwc.h"
  33 #include "pwc-dec1.h"
  34 #include "pwc-dec23.h"
  35
  36 int pwc_decompress(struct pwc_device *pdev, struct pwc_frame_buf *fbuf)
  37 {
  38         int n, line, col;
  39         void *yuv, *image;
  40         u16 *src;
  41         u16 *dsty, *dstu, *dstv;
  42
  43         image = vb2_plane_vaddr(&fbuf->vb, 0);
  44
  45         yuv = fbuf->data + pdev->frame_header_size;  /* Skip header */
  46
  47         /* Raw format; that's easy... */
  48         if (pdev->pixfmt != V4L2_PIX_FMT_YUV420)
  49         {
  50                 struct pwc_raw_frame *raw_frame = image;
  51                 raw_frame->type = cpu_to_le16(pdev->type);
  52                 raw_frame->vbandlength = cpu_to_le16(pdev->vbandlength);
  53                         /* cmd_buf is always 4 bytes, but sometimes, only the
  54                          * first 3 bytes is filled (Nala case). We can
  55                          * determine this using the type of the webcam */
  56                 memcpy(raw_frame->cmd, pdev->cmd_buf, 4);
  57                 memcpy(raw_frame+1, yuv, pdev->frame_size);
  58                 vb2_set_plane_payload(&fbuf->vb, 0,
  59                         pdev->frame_size + sizeof(struct pwc_raw_frame));
  60                 return 0;
  61         }
  62
  63         vb2_set_plane_payload(&fbuf->vb, 0,
  64                               pdev->width * pdev->height * 3 / 2);
  65
  66         if (pdev->vbandlength == 0) {
  67                 /* Uncompressed mode.
  68                  *
  69                  * We do some byte shuffling here to go from the
  70                  * native format to YUV420P.
  71                  */
  72                 src = (u16 *)yuv;
  73                 n = pdev->width * pdev->height;
  74                 dsty = (u16 *)(image);
  75                 dstu = (u16 *)(image + n);
  76                 dstv = (u16 *)(image + n + n / 4);
  77
  78                 for (line = 0; line < pdev->height; line++) {
  79                         for (col = 0; col < pdev->width; col += 4) {
  80                                 *dsty++ = *src++;
  81                                 *dsty++ = *src++;
  82                                 if (line & 1)
  83                                         *dstv++ = *src++;
  84                                 else
  85                                         *dstu++ = *src++;
  86                         }
  87                 }
  88
  89                 return 0;
  90         }
  91
  92         /*
  93          * Compressed;
  94          * the decompressor routines will write the data in planar format
  95          * immediately.
  96          */
  97         if (DEVICE_USE_CODEC1(pdev->type)) {
  98
  99                 /* TODO & FIXME */
 100                 PWC_ERROR("This chipset is not supported for now\n");
 101                 return -ENXIO; /* No such device or address: missing decompressor */
 102
 103         } else {
 104                 pwc_dec23_decompress(pdev, yuv, image);
 105         }
 106         return 0;
 107 }