mirror of https://gitee.com/openkylin/linux.git
64 lines
1.8 KiB
C
64 lines
1.8 KiB
C
/*
|
|
* 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[] = {
|
|
0xff, 0xff, 0x00, 0xc4, 0xc4, 0x96,
|
|
0x00,
|
|
0x00, /* seq */
|
|
0x00,
|
|
0x00,
|
|
0x00, /* avg luminance lower 8 bit */
|
|
0x00, /* avg luminance higher 8 bit */
|
|
};
|
|
|
|
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 > 5)) {
|
|
sd->sof_read++;
|
|
if (sd->sof_read == 11)
|
|
sd->avg_lum_l = m[i];
|
|
if (sd->sof_read == 12)
|
|
sd->avg_lum = (m[i] << 8) + sd->avg_lum_l;
|
|
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;
|
|
}
|