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/* Linux driver for Philips webcam

   Decompression frontend.

   (C) 1999-2003 Nemosoft Unv.

   (C) 2004-2006 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

   vim: set ts=8:

*/

#include <asm/current.h>

#include <asm/types.h>

#include "pwc.h"

#include "pwc-uncompress.h"

#include "pwc-dec1.h"

#include "pwc-dec23.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;

        fbuf = pdev->read_frame;

        if (fbuf == NULL)

                return -EFAULT;

        image  = pdev->image_data;

        image += pdev->images[pdev->fill_image].offset;

        yuv = fbuf->data + pdev->frame_header_size;  /* Skip header */

        /* Raw format; that's easy... */

        if (pdev->vpalette == VIDEO_PALETTE_RAW)

        {

                struct pwc_raw_frame *raw_frame = image;

                raw_frame->type = cpu_to_le16(pdev->type);

                raw_frame->vbandlength = cpu_to_le16(pdev->vbandlength);

                        /* cmd_buf is always 4 bytes, but sometimes, only the

                         * first 3 bytes is filled (Nala case). We can

                         * determine this using the type of the webcam */

                memcpy(raw_frame->cmd, pdev->cmd_buf, 4);

                memcpy(raw_frame+1, 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);

                }

                return 0;

        }

        /*

         * Compressed;

         * the decompressor routines will write the data in planar format

         * immediately.

         */

        if (pdev->vsize == PSZ_VGA && pdev->vframes == 5 && pdev->vsnapshot) {

                PWC_ERROR("Mode Bayer is not supported for now\n");

                /* flags |= PWCX_FLAG_BAYER; */

                return -ENXIO; /* No such device or address: missing decompressor */

        }

        if (DEVICE_USE_CODEC1(pdev->type)) {

                /* TODO & FIXME */

                PWC_ERROR("This chipset is not supported for now\n");

                return -ENXIO; /* No such device or address: missing decompressor */

        } else {

                pwc_dec23_decompress(pdev, yuv, image, PWCX_FLAG_PLANAR);

        }

        return 0;

}

/* vim: set cino= formatoptions=croql cindent shiftwidth=8 tabstop=8: */