LXR linux/drivers/media/usb/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
  36int 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}
 108