diff options
Diffstat (limited to 'drivers/media/video/pwc/pwc-uncompress.c')
| -rw-r--r-- | drivers/media/video/pwc/pwc-uncompress.c | 146 |
1 files changed, 146 insertions, 0 deletions
diff --git a/drivers/media/video/pwc/pwc-uncompress.c b/drivers/media/video/pwc/pwc-uncompress.c new file mode 100644 index 00000000000..ef4204eab6c --- /dev/null +++ b/drivers/media/video/pwc/pwc-uncompress.c @@ -0,0 +1,146 @@ +/* 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; +} + + |