/* Linux driver for Philips webcam
   Decompression frontend.
   (C) 1999-2003 Nemosoft Unv.
   (C) 2004      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
*/

#include "pwc.h"
#include "pwc-uncompress.h"
#include "pwc-dec1.h"
#include "pwc-dec23.h"
#include "linux_usbif.h"

int pwc_decompress(struct pwc_device *pdev)
{
	int n, line, col, stride;
	__u16 *src;
	__u16 *dsty, *dstu, *dstv;

	if (pdev == NULL)
		return -EFAULT;

	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 *)grabbuf;
		n = pdev->view.x * pdev->view.y;

		/* offset in Y plane */
		stride = pdev->view.x * pdev->offset.y + pdev->offset.x;
		dsty = (__u16 *)(yuv + stride);

		/* offsets in U/V planes */
		stride = pdev->view.x * pdev->offset.y / 4 + pdev->offset.x / 2;
		dstu = (__u16 *)(yuv + n +         stride);
		dstv = (__u16 *)(yuv + 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);
		}
	}
	else {
		/* Compressed; the decompressor routines will write the data
		   in planar format immediately.
		   */
		int flags;

		flags = PWCX_FLAG_PLANAR;
		if (pdev->vsize == PSZ_VGA && pdev->vframes == 5 && pdev->vsnapshot)
		{
			Debug(KERN_ERR "pwc: Mode Bayer is not supported for now\n");
			flags |= PWCX_FLAG_BAYER;
			return -ENXIO; /* No such device or address: missing decompressor */
		}

		switch (pdev->type)
		{
			case 675:
			case 680:
			case 690:
			case 720:
			case 730:
			case 740:
			case 750:
				pwc_dec23_decompress(&pdev->image, &pdev->view, &pdev->offset,
						grabbuf, yuv, flags,
						pdev->decompress_data, pdev->vbandlength);
				break;
			case 645:
			case 646:
				/* TODO & FIXME */
				return -ENXIO; /* No such device or address: missing decompressor */
				break;
		}
	}
	return 0;
}