patch-2.4.5 linux/drivers/usb/pwc-uncompress.c

• Lines: 158
• Date: Fri May 25 09:48:50 2001
• Orig file: v2.4.4/linux/drivers/usb/pwc-uncompress.c
• Orig date: Wed Dec 31 16:00:00 1969

diff -u --recursive --new-file v2.4.4/linux/drivers/usb/pwc-uncompress.c linux/drivers/usb/pwc-uncompress.c
@@ -0,0 +1,157 @@
+/* Linux driver for Philips webcam 
+   Decompression frontend.
+   (C) 1999-2001 Nemosoft Unv. (webcam@smcc.demon.nl)
+
+   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
+*/
+/*
+   This is where the decompression routines register and unregister 
+   themselves. It also has a decompressor wrapper function.
+*/
+
+#include "pwc.h"
+#include "pwc-uncompress.h"
+
+
+/* This contains a list of all registered decompressors */
+static LIST_HEAD(pwc_decompressor_list);
+
+/* Should the pwc_decompress structure ever change, we increase the 
+   version number so that we don't get nasty surprises, or can 
+   dynamicly adjust our structure.
+ */
+const int pwc_decompressor_version = PWC_MAJOR;
+
+/* Add decompressor to list, ignoring duplicates */
+void pwc_register_decompressor(struct pwc_decompressor *pwcd)
+{
+	if (pwc_find_decompressor(pwcd->type) == NULL) {
+		Debug("Adding decompressor for model %d.\n", pwcd->type);
+		list_add_tail(&pwcd->pwcd_list, &pwc_decompressor_list);
+	}
+}
+
+/* Remove decompressor from list */
+void pwc_unregister_decompressor(int type)
+{
+	struct pwc_decompressor *find;
+	
+	find = pwc_find_decompressor(type);
+	if (find != NULL) {
+		Debug("Removing decompressor for model %d.\n", type);
+		list_del(&find->pwcd_list);
+	}
+}
+
+/* Find decompressor in list */
+struct pwc_decompressor *pwc_find_decompressor(int type)
+{
+	struct list_head *tmp;
+	struct pwc_decompressor *pwcd;
+
+	list_for_each(tmp, &pwc_decompressor_list) {
+		pwcd  = list_entry(tmp, struct pwc_decompressor, pwcd_list);
+		if (pwcd->type == type)
+			return pwcd;
+	}
+	return NULL;
+}
+
+
+
+int pwc_decompress(struct pwc_device *pdev)
+{
+	struct pwc_frame_buf *fbuf;
+	int n, l, c, w;
+	void *yuv, *image, *dst;
+	
+	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;
+
+#if PWC_DEBUG
+	/* This is a quickie */
+	if (pdev->vpalette == VIDEO_PALETTE_RAW) {
+		memcpy(image, fbuf->data, pdev->frame_size);
+		return 0;
+	}
+#endif
+
+	/* Compressed formats are decompressed in decompress_buffer, then 
+	 * transformed into the desired format 
+	 */
+	yuv = pdev->decompress_buffer;
+	n = 0;
+	if (pdev->vbandlength == 0) { /* uncompressed */
+		yuv = fbuf->data + pdev->frame_header_size;  /* Skip header */
+	}
+	else {
+		if (pdev->decompressor)
+			n = pdev->decompressor->decompress(pdev->decompress_data, pdev->image.x, pdev->image.y, pdev->vbandlength, yuv, fbuf->data + pdev->frame_header_size, 0);
+		else
+			n = -ENXIO; /* No such device or address: missing decompressor */
+	}
+	if (n < 0) {
+		Err("Error in decompression engine: %d\n", n);
+		return n;
+	}
+
+	/* At this point 'yuv' always points to the uncompressed, non-scaled YUV420I data */
+	if (pdev->image.x == pdev->view.x && pdev->image.y == pdev->view.y) {
+		/* Sizes matches; make it quick */
+		switch(pdev->vpalette) {
+		case VIDEO_PALETTE_YUV420:
+			memcpy(image, yuv, pdev->image.size);
+			break;
+		}
+	}
+	else {
+ 		/* Size mismatch; use viewport conversion routines */
+	 	switch(pdev->vpalette) {
+		case VIDEO_PALETTE_YUV420:
+			dst = image + pdev->offset.size;
+			w = pdev->view.x * 6;
+			c = pdev->image.x * 6;
+			for (l = 0; l < pdev->image.y; l++) {
+				memcpy(dst, yuv, c);
+				dst += w;
+				yuv += c;
+			}
+			break;
+ 		}
+ 	}
+	return 0;
+}
+
+/* Make sure these functions are available for the decompressor plugin
+   both when this code is compiled into the kernel or as as module.
+ */
+
+EXPORT_SYMBOL_NOVERS(pwc_decompressor_version);
+EXPORT_SYMBOL(pwc_register_decompressor);
+EXPORT_SYMBOL(pwc_unregister_decompressor);
+EXPORT_SYMBOL(pwc_find_decompressor);