sn9c2028.h

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/*
 * SN9C2028 common functions
 *
 * Copyright (C) 2009 Theodore Kilgore <kilgota@auburn,edu>
 *
 * Based closely upon the file gspca/pac_common.h
 *
 * 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
 *
 */

static const unsigned char sn9c2028_sof_marker[5] =
    { 0xff, 0xff, 0x00, 0xc4, 0xc4 };

static unsigned char *sn9c2028_find_sof(struct gspca_dev *gspca_dev,
                    unsigned char *m, int len)
{
    struct sd *sd = (struct sd *) gspca_dev;
    int i;

    /* Search for the SOF marker (fixed part) in the header */
    for (i = 0; i < len; i++) {
        if (m[i] == sn9c2028_sof_marker[sd->sof_read]) {
            sd->sof_read++;
            if (sd->sof_read == sizeof(sn9c2028_sof_marker)) {
                PDEBUG(D_FRAM,
                    "SOF found, bytes to analyze: %u."
                    " Frame starts at byte #%u",
                    len, i + 1);
                sd->sof_read = 0;
                return m + i + 1;
            }
        } else {
            sd->sof_read = 0;
        }
    }

    return NULL;
}