aboutsummaryrefslogtreecommitdiff
path: root/drivers/usb/media/pwc/pwc-uncompress.c
blob: ef4204eab6c4459aaa1ccbadd2f1876e73e09262 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
/* 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 <asm/current.h>
#include <asm/types.h>

#include "pwc.h"
#include "pwc-uncompress.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;
#if defined(__KERNEL__) && defined(PWC_MAGIC)
	if (pdev->magic != PWC_MAGIC) {
		Err("pwc_decompress(): magic failed.\n");
		return -EFAULT;
	}
#endif

	fbuf = pdev->read_frame;
	if (fbuf == NULL)
		return -EFAULT;
	image = pdev->image_ptr[pdev->fill_image];
	if (!image)
		return -EFAULT;

	yuv = fbuf->data + pdev->frame_header_size;  /* Skip header */

	/* Raw format; that's easy... */
	if (pdev->vpalette == VIDEO_PALETTE_RAW)
	{
		memcpy(image, 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);
			}
	}
	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)
		 {
		   printk(KERN_ERR "pwc: Mode Bayer is not supported for now\n");
		   flags |= PWCX_FLAG_BAYER;
		   return -ENXIO; /* No such device or address: missing decompressor */
		 }

#if 0
		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, yuv, image, flags,
				pdev->decompress_data, pdev->vbandlength);
		    break;
		  case 645:
		  case 646:
		    /* TODO & FIXME */
		    return -ENXIO; /* Missing decompressor */
		    break;
		 }
#endif
	}
	return 0;
}