/* Linux driver for Philips webcam
Decompression frontend.
(C) 1999-2003 Nemosoft Unv.
(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
vim: set ts=8:
*/
#include <asm/current.h>
#include <asm/types.h>
#include "pwc.h"
#include "pwc-uncompress.h"
#include "pwc-dec1.h"
#include "pwc-dec23.h"
int pwc_decompress(struct pwc_device *pdev)
{
struct pwc_frame_buf *fbuf;
int n, line, col, stride;
void *yuv, *image;
u16 *src;
u16 *dsty, *dstu, *dstv;
if (pdev == NULL)
return -EFAULT;
fbuf = pdev->read_frame;
if (fbuf == NULL)
return -EFAULT;
image = pdev->image_data;
image += pdev->images[pdev->fill_image].offset;
yuv = fbuf->data + pdev->frame_header_size; /* Skip header */
/* Raw format; that's easy... */
if (pdev->vpalette == VIDEO_PALETTE_RAW)
{
struct pwc_raw_frame *raw_frame = image;
raw_frame->type = cpu_to_le16(pdev->type);
raw_frame->vbandlength = cpu_to_le16(pdev->vbandlength);
/* cmd_buf is always 4 bytes, but sometimes, only the
* first 3 bytes is filled (Nala case). We can
* determine this using the type of the webcam */
memcpy(raw_frame->cmd, pdev->cmd_buf, 4);
memcpy(raw_frame+1, yuv, pdev->frame_size);
return 0;
}
if (pdev->vbandlength == 0) {
/* Uncompressed mode.
* We copy the data into the output buffer, using the viewport
* size (which may be larger than the image size).
* Unfortunately we have to do a bit of byte stuffing to get
* the desired output format/size.
*
* We do some byte shuffling here to go from the
* native format to YUV420P.
*/
src = (u16 *)yuv;
n = pdev->view.x * pdev->view.y;
/* offset in Y plane */
stride = pdev->view.x * pdev->offset.y + pdev->offset.x;
dsty = (u16 *)(image + stride);
/* offsets in U/V planes */
stride = pdev->view.x * pdev->offset.y / 4 + pdev->offset.x / 2;
dstu = (u16 *)(image + n + stride);
dstv = (u16 *)(image + n + n / 4 + stride);
/* increment after each line */
stride = (pdev->view.x - pdev->image.x) / 2; /* u16 is 2 bytes */
for (line = 0; line < pdev->image.y; line++) {
for (col = 0; col < pdev->image.x; col += 4) {
*dsty++ = *src++;
*dsty++ = *src++;
if (line & 1)
*dstv++ = *src++;
else
*dstu++ = *src++;
}
dsty += stride;
if (line & 1)
dstv += (stride >> 1);
else
dstu += (stride >> 1);
}
return 0;
}
/*
* Compressed;
* the decompressor routines will write the data in planar format
* immediately.
*/
if (pdev->vsize == PSZ_VGA && pdev->vframes == 5 && pdev->vsnapshot) {
PWC_ERROR("Mode Bayer is not supported for now\n");
/* flags |= PWCX_FLAG_BAYER; */
return -ENXIO; /* No such device or address: missing decompressor */
}
if (DEVICE_USE_CODEC1(pdev->type)) {
/* TODO & FIXME */
PWC_ERROR("This chipset is not supported for now\n");
return -ENXIO; /* No such device or address: missing decompressor */
} else {
pwc_dec23_decompress(pdev, yuv, image, PWCX_FLAG_PLANAR);
}
return 0;
}
/* vim: set cino= formatoptions=croql cindent shiftwidth=8 tabstop=8: */
