pwc-misc.c

webcam device driver

/* Linux driver for Philips webcam 
   Various miscellaneous functions and tables.
   (C) 1999-2003 Nemosoft Unv.
   (C) 2004-2006 Luc Saillard ([e-mail])

   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 <[e-mail]>.
   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
*/

#include <linux/slab.h>

#include "pwc.h"

const struct pwc_coord pwc_image_sizes[PSZ_MAX] =
{
	{ 128,  96, 0 }, /* sqcif */
	{ 160, 120, 0 }, /* qsif */
	{ 176, 144, 0 }, /* qcif */
	{ 320, 240, 0 }, /* sif */
	{ 352, 288, 0 }, /* cif */
	{ 640, 480, 0 }, /* vga */
};

/* x,y -> PSZ_ */
int pwc_decode_size(struct pwc_device *pdev, int width, int height)
{
	int i, find;

	/* Make sure we don't go beyond our max size.
           NB: we have different limits for RAW and normal modes. In case
           you don't have the decompressor loaded or use RAW mode, 
           the maximum viewable size is smaller.
        */
	if (pdev->vpalette == VIDEO_PALETTE_RAW)
	{
		if (width > pdev->abs_max.x || height > pdev->abs_max.y)
		{
			PWC_DEBUG_SIZE("VIDEO_PALETTE_RAW: going beyond abs_max.\n");
                	return -1;
                }
	}
	else
	{
		if (width > pdev->view_max.x || height > pdev->view_max.y)
		{
			PWC_DEBUG_SIZE("VIDEO_PALETTE_not RAW: going beyond view_max.\n");
			return -1;
		}
	}

	/* Find the largest size supported by the camera that fits into the
	   requested size.
	 */
	find = -1;
	for (i = 0; i < PSZ_MAX; i++) {
		if (pdev->image_mask & (1 << i)) {
			if (pwc_image_sizes[i].x <= width && pwc_image_sizes[i].y <= height)
				find = i;
		}
	}
	return find;
}

/* initialize variables depending on type and decompressor*/
void pwc_construct(struct pwc_device *pdev)
{
  	if (DEVICE_USE_CODEC1(pdev->type)) {

		pdev->view_min.x = 128;
		pdev->view_min.y =  96;
		pdev->view_max.x = 352;
		pdev->view_max.y = 288;
                pdev->abs_max.x  = 352;
                pdev->abs_max.y  = 288;
		pdev->image_mask = 1 << PSZ_SQCIF | 1 << PSZ_QCIF | 1 << PSZ_CIF;
		pdev->vcinterface = 2;
		pdev->vendpoint = 4;
		pdev->frame_header_size = 0;
		pdev->frame_trailer_size = 0;

	} else if (DEVICE_USE_CODEC3(pdev->type)) {

	   	pdev->view_min.x = 160;
		pdev->view_min.y = 120;
		pdev->view_max.x = 640;
		pdev->view_max.y = 480;
		pdev->image_mask = 1 << PSZ_QSIF | 1 << PSZ_SIF | 1 << PSZ_VGA;
                pdev->abs_max.x = 640;
                pdev->abs_max.y = 480;
		pdev->vcinterface = 3;
		pdev->vendpoint = 5;
		pdev->frame_header_size = TOUCAM_HEADER_SIZE;
		pdev->frame_trailer_size = TOUCAM_TRAILER_SIZE;

	} else /* if (DEVICE_USE_CODEC2(pdev->type)) */ {

		pdev->view_min.x = 128;
		pdev->view_min.y =  96;
		/* Anthill bug #38: PWC always reports max size, even without PWCX */
		pdev->view_max.x = 640;
		pdev->view_max.y = 480;
		pdev->image_mask = 1 << PSZ_SQCIF | 1 << PSZ_QSIF | 1 << PSZ_QCIF | 1 << PSZ_SIF | 1 << PSZ_CIF | 1 << PSZ_VGA;
                pdev->abs_max.x = 640;
                pdev->abs_max.y = 480;
		pdev->vcinterface = 3;
		pdev->vendpoint = 4;
		pdev->frame_header_size = 0;
		pdev->frame_trailer_size = 0;
	}
	pdev->vpalette = VIDEO_PALETTE_YUV420P; /* default */
	pdev->view_min.size = pdev->view_min.x * pdev->view_min.y;
	pdev->view_max.size = pdev->view_max.x * pdev->view_max.y;
	/* length of image, in YUV format; always allocate enough memory. */
	pdev->len_per_image = PAGE_ALIGN((pdev->abs_max.x * pdev->abs_max.y * 3) / 2);
}