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path: root/drivers/media/video/pwc/pwc-uncompress.c
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Diffstat (limited to 'drivers/media/video/pwc/pwc-uncompress.c')
-rw-r--r--drivers/media/video/pwc/pwc-uncompress.c146
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..b37a89a163f
--- /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;
+}
+
+