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-uncompress.h"
34#include "pwc-dec1.h"
35#include "pwc-dec23.h"
36
37int pwc_decompress(struct pwc_device *pdev)
38{
39	struct pwc_frame_buf *fbuf;
40	int n, line, col, stride;
41	void *yuv, *image;
42	u16 *src;
43	u16 *dsty, *dstu, *dstv;
44
45	if (pdev == NULL)
46		return -EFAULT;
47
48	fbuf = pdev->read_frame;
49	if (fbuf == NULL)
50		return -EFAULT;
51	image  = pdev->image_data;
52	image += pdev->images[pdev->fill_image].offset;
53
54	yuv = fbuf->data + pdev->frame_header_size;  /* Skip header */
55
56	/* Raw format; that's easy... */
57	if (pdev->vpalette == VIDEO_PALETTE_RAW)
58	{
59		struct pwc_raw_frame *raw_frame = image;
60		raw_frame->type = cpu_to_le16(pdev->type);
61		raw_frame->vbandlength = cpu_to_le16(pdev->vbandlength);
62			/* cmd_buf is always 4 bytes, but sometimes, only the
63			 * first 3 bytes is filled (Nala case). We can
64			 * determine this using the type of the webcam */
65		memcpy(raw_frame->cmd, pdev->cmd_buf, 4);
66		memcpy(raw_frame+1, yuv, pdev->frame_size);
67		return 0;
68	}
69
70	if (pdev->vbandlength == 0) {
71		/* Uncompressed mode.
72		 * We copy the data into the output buffer, using the viewport
73		 * size (which may be larger than the image size).
74		 * Unfortunately we have to do a bit of byte stuffing to get
75		 * the desired output format/size.
76		 *
77		 * We do some byte shuffling here to go from the
78		 * native format to YUV420P.
79		 */
80		src = (u16 *)yuv;
81		n = pdev->view.x * pdev->view.y;
82
83		/* offset in Y plane */
84		stride = pdev->view.x * pdev->offset.y + pdev->offset.x;
85		dsty = (u16 *)(image + stride);
86
87		/* offsets in U/V planes */
88		stride = pdev->view.x * pdev->offset.y / 4 + pdev->offset.x / 2;
89		dstu = (u16 *)(image + n +         stride);
90		dstv = (u16 *)(image + n + n / 4 + stride);
91
92		/* increment after each line */
93		stride = (pdev->view.x - pdev->image.x) / 2; /* u16 is 2 bytes */
94
95		for (line = 0; line < pdev->image.y; line++) {
96			for (col = 0; col < pdev->image.x; col += 4) {
97				*dsty++ = *src++;
98				*dsty++ = *src++;
99				if (line & 1)
100					*dstv++ = *src++;
101				else
102					*dstu++ = *src++;
103			}
104			dsty += stride;
105			if (line & 1)
106				dstv += (stride >> 1);
107			else
108				dstu += (stride >> 1);
109		}
110
111		return 0;
112	}
113
114	/*
115	 * Compressed;
116	 * the decompressor routines will write the data in planar format
117	 * immediately.
118	 */
119	if (pdev->vsize == PSZ_VGA && pdev->vframes == 5 && pdev->vsnapshot) {
120		PWC_ERROR("Mode Bayer is not supported for now\n");
121		/* flags |= PWCX_FLAG_BAYER; */
122		return -ENXIO; /* No such device or address: missing decompressor */
123	}
124
125	if (DEVICE_USE_CODEC1(pdev->type)) {
126
127		PWC_ERROR("This chipset is not supported for now\n");
128		return -ENXIO; /* No such device or address: missing decompressor */
129
130	} else {
131		pwc_dec23_decompress(pdev, yuv, image, PWCX_FLAG_PLANAR);
132	}
133	return 0;
134}
135
136
137/* vim: set cino= formatoptions=croql cindent shiftwidth=8 tabstop=8: */
138