1 /* Linux driver for Philips webcam
2 Decompression frontend.
3 (C) 1999-2003 Nemosoft Unv.
4 (C) 2004-2006 Luc Saillard (luc@saillard.org)
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.
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.
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.
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
29 #include <asm/current.h>
30 #include <asm/types.h>
33 #include "pwc-uncompress.h"
35 #include "pwc-dec23.h"
37 int pwc_decompress(struct pwc_device *pdev)
39 struct pwc_frame_buf *fbuf;
40 int n, line, col, stride;
43 u16 *dsty, *dstu, *dstv;
45 fbuf = pdev->read_frame;
46 image = pdev->image_data;
47 image += pdev->images[pdev->fill_image].offset;
49 yuv = fbuf->data + pdev->frame_header_size; /* Skip header */
51 /* Raw format; that's easy... */
52 if (pdev->pixfmt != V4L2_PIX_FMT_YUV420)
54 struct pwc_raw_frame *raw_frame = image;
55 raw_frame->type = cpu_to_le16(pdev->type);
56 raw_frame->vbandlength = cpu_to_le16(pdev->vbandlength);
57 /* cmd_buf is always 4 bytes, but sometimes, only the
58 * first 3 bytes is filled (Nala case). We can
59 * determine this using the type of the webcam */
60 memcpy(raw_frame->cmd, pdev->cmd_buf, 4);
61 memcpy(raw_frame+1, yuv, pdev->frame_size);
65 if (pdev->vbandlength == 0) {
67 * We copy the data into the output buffer, using the viewport
68 * size (which may be larger than the image size).
69 * Unfortunately we have to do a bit of byte stuffing to get
70 * the desired output format/size.
72 * We do some byte shuffling here to go from the
73 * native format to YUV420P.
76 n = pdev->view.x * pdev->view.y;
78 /* offset in Y plane */
79 stride = pdev->view.x * pdev->offset.y + pdev->offset.x;
80 dsty = (u16 *)(image + stride);
82 /* offsets in U/V planes */
83 stride = pdev->view.x * pdev->offset.y / 4 + pdev->offset.x / 2;
84 dstu = (u16 *)(image + n + stride);
85 dstv = (u16 *)(image + n + n / 4 + stride);
87 /* increment after each line */
88 stride = (pdev->view.x - pdev->image.x) / 2; /* u16 is 2 bytes */
90 for (line = 0; line < pdev->image.y; line++) {
91 for (col = 0; col < pdev->image.x; col += 4) {
101 dstv += (stride >> 1);
103 dstu += (stride >> 1);
111 * the decompressor routines will write the data in planar format
114 if (pdev->vsize == PSZ_VGA && pdev->vframes == 5 && pdev->vsnapshot) {
115 PWC_ERROR("Mode Bayer is not supported for now\n");
116 /* flags |= PWCX_FLAG_BAYER; */
117 return -ENXIO; /* No such device or address: missing decompressor */
120 if (DEVICE_USE_CODEC1(pdev->type)) {
123 PWC_ERROR("This chipset is not supported for now\n");
124 return -ENXIO; /* No such device or address: missing decompressor */
127 pwc_dec23_decompress(pdev, yuv, image, PWCX_FLAG_PLANAR);
133 /* vim: set cino= formatoptions=croql cindent shiftwidth=8 tabstop=8: */