/* 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 . 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 #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; }