1/* Linux driver for Philips webcam 2 Decompression frontend. 3 (C) 1999-2003 Nemosoft Unv. (webcam@smcc.demon.nl) 4 5 This program is free software; you can redistribute it and/or modify 6 it under the terms of the GNU General Public License as published by 7 the Free Software Foundation; either version 2 of the License, or 8 (at your option) any later version. 9 10 This program is distributed in the hope that it will be useful, 11 but WITHOUT ANY WARRANTY; without even the implied warranty of 12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 13 GNU General Public License for more details. 14 15 You should have received a copy of the GNU General Public License 16 along with this program; if not, write to the Free Software 17 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 18*/ 19/* 20 This is where the decompression routines register and unregister 21 themselves. It also has a decompressor wrapper function. 22*/ 23 24#include <asm/types.h> 25 26#include "pwc.h" 27#include "pwc-uncompress.h" 28 29 30/* This contains a list of all registered decompressors */ 31static LIST_HEAD(pwc_decompressor_list); 32 33/* Should the pwc_decompress structure ever change, we increase the 34 version number so that we don't get nasty surprises, or can 35 dynamically adjust our structure. 36 */ 37const int pwc_decompressor_version = PWC_MAJOR; 38 39/* Add decompressor to list, ignoring duplicates */ 40void pwc_register_decompressor(struct pwc_decompressor *pwcd) 41{ 42 if (pwc_find_decompressor(pwcd->type) == NULL) { 43 Trace(TRACE_PWCX, "Adding decompressor for model %d.\n", pwcd->type); 44 list_add_tail(&pwcd->pwcd_list, &pwc_decompressor_list); 45 } 46} 47 48/* Remove decompressor from list */ 49void pwc_unregister_decompressor(int type) 50{ 51 struct pwc_decompressor *find; 52 53 find = pwc_find_decompressor(type); 54 if (find != NULL) { 55 Trace(TRACE_PWCX, "Removing decompressor for model %d.\n", type); 56 list_del(&find->pwcd_list); 57 } 58} 59 60/* Find decompressor in list */ 61struct pwc_decompressor *pwc_find_decompressor(int type) 62{ 63 struct list_head *tmp; 64 struct pwc_decompressor *pwcd; 65 66 list_for_each(tmp, &pwc_decompressor_list) { 67 pwcd = list_entry(tmp, struct pwc_decompressor, pwcd_list); 68 if (pwcd->type == type) 69 return pwcd; 70 } 71 return NULL; 72} 73 74 75 76int pwc_decompress(struct pwc_device *pdev) 77{ 78 struct pwc_frame_buf *fbuf; 79 int n, line, col, stride; 80 void *yuv, *image; 81 u16 *src; 82 u16 *dsty, *dstu, *dstv; 83 84 85 if (pdev == NULL) 86 return -EFAULT; 87#if defined(__KERNEL__) && defined(PWC_MAGIC) 88 if (pdev->magic != PWC_MAGIC) { 89 Err("pwc_decompress(): magic failed.\n"); 90 return -EFAULT; 91 } 92#endif 93 94 fbuf = pdev->read_frame; 95 if (fbuf == NULL) 96 return -EFAULT; 97 image = pdev->image_ptr[pdev->fill_image]; 98 if (!image) 99 return -EFAULT; 100 101 yuv = fbuf->data + pdev->frame_header_size; /* Skip header */ 102 if (pdev->vbandlength == 0) { 103 /* Uncompressed mode. We copy the data into the output buffer, 104 using the viewport size (which may be larger than the image 105 size). Unfortunately we have to do a bit of byte stuffing 106 to get the desired output format/size. 107 */ 108 /* 109 * We do some byte shuffling here to go from the 110 * native format to YUV420P. 111 */ 112 src = (u16 *)yuv; 113 n = pdev->view.x * pdev->view.y; 114 115 /* offset in Y plane */ 116 stride = pdev->view.x * pdev->offset.y + pdev->offset.x; 117 dsty = (u16 *)(image + stride); 118 119 /* offsets in U/V planes */ 120 stride = pdev->view.x * pdev->offset.y / 4 + pdev->offset.x / 2; 121 dstu = (u16 *)(image + n + stride); 122 dstv = (u16 *)(image + n + n / 4 + stride); 123 124 /* increment after each line */ 125 stride = (pdev->view.x - pdev->image.x) / 2; /* u16 is 2 bytes */ 126 127 for (line = 0; line < pdev->image.y; line++) { 128 for (col = 0; col < pdev->image.x; col += 4) { 129 *dsty++ = *src++; 130 *dsty++ = *src++; 131 if (line & 1) 132 *dstv++ = *src++; 133 else 134 *dstu++ = *src++; 135 } 136 dsty += stride; 137 if (line & 1) 138 dstv += (stride >> 1); 139 else 140 dstu += (stride >> 1); 141 } 142 } 143 else { 144 /* Compressed; the decompressor routines will write the data 145 in planar format immediately. 146 */ 147 if (pdev->decompressor) 148 pdev->decompressor->decompress( 149 &pdev->image, &pdev->view, &pdev->offset, 150 yuv, image, 151 1, 152 pdev->decompress_data, pdev->vbandlength); 153 else 154 return -ENXIO; /* No such device or address: missing decompressor */ 155 } 156 return 0; 157} 158 159/* Make sure these functions are available for the decompressor plugin 160 both when this code is compiled into the kernel or as as module. 161 */ 162 163EXPORT_SYMBOL_NOVERS(pwc_decompressor_version); 164EXPORT_SYMBOL(pwc_register_decompressor); 165EXPORT_SYMBOL(pwc_unregister_decompressor); 166