135 lines
3.5 KiB
C
135 lines
3.5 KiB
C
|
/*
|
||
|
|
* Pixart PAC207BCA / PAC73xx common functions
|
||
|
|
*
|
||
|
|
* Copyright (C) 2008 Hans de Goede <j.w.r.degoede@hhs.nl>
|
||
|
|
* Copyright (C) 2005 Thomas Kaiser thomas@kaiser-linux.li
|
||
|
|
* Copyleft (C) 2005 Michel Xhaard mxhaard@magic.fr
|
||
|
|
*
|
||
|
|
* V4L2 by Jean-Francois Moine <http://moinejf.free.fr>
|
||
|
|
*
|
||
|
|
* 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
|
||
|
|
*
|
||
|
|
*/
|
||
|
|
|
||
|
|
/* We calculate the autogain at the end of the transfer of a frame, at this
|
||
|
|
moment a frame with the old settings is being captured and transmitted. So
|
||
|
|
if we adjust the gain or exposure we must ignore atleast the next frame for
|
||
|
|
the new settings to come into effect before doing any other adjustments. */
|
||
|
|
#define PAC_AUTOGAIN_IGNORE_FRAMES 2
|
||
|
|
|
||
|
|
static const unsigned char pac_sof_marker[5] =
|
||
|
|
{ 0xff, 0xff, 0x00, 0xff, 0x96 };
|
||
|
|
|
||
|
|
/*
|
||
|
|
The following state machine finds the SOF marker sequence
|
||
|
|
0xff, 0xff, 0x00, 0xff, 0x96 in a byte stream.
|
||
|
|
|
||
|
|
+----------+
|
||
|
|
| 0: START |<---------------\
|
||
|
|
+----------+<-\ |
|
||
|
|
| \---/otherwise |
|
||
|
|
v 0xff |
|
||
|
|
+----------+ otherwise |
|
||
|
|
| 1 |--------------->*
|
||
|
|
| | ^
|
||
|
|
+----------+ |
|
||
|
|
| |
|
||
|
|
v 0xff |
|
||
|
|
+----------+<-\0xff |
|
||
|
|
/->| |--/ |
|
||
|
|
| | 2 |--------------->*
|
||
|
|
| | | otherwise ^
|
||
|
|
| +----------+ |
|
||
|
|
| | |
|
||
|
|
| v 0x00 |
|
||
|
|
| +----------+ |
|
||
|
|
| | 3 | |
|
||
|
|
| | |--------------->*
|
||
|
|
| +----------+ otherwise ^
|
||
|
|
| | |
|
||
|
|
0xff | v 0xff |
|
||
|
|
| +----------+ |
|
||
|
|
\--| 4 | |
|
||
|
|
| |----------------/
|
||
|
|
+----------+ otherwise
|
||
|
|
|
|
||
|
|
v 0x96
|
||
|
|
+----------+
|
||
|
|
| FOUND |
|
||
|
|
+----------+
|
||
|
|
*/
|
||
|
|
|
||
|
|
static unsigned char *pac_find_sof(struct gspca_dev *gspca_dev, u8 *sof_read,
|
||
|
|
unsigned char *m, int len)
|
||
|
|
{
|
||
|
|
int i;
|
||
|
|
|
||
|
|
/* Search for the SOF marker (fixed part) in the header */
|
||
|
|
for (i = 0; i < len; i++) {
|
||
|
|
switch (*sof_read) {
|
||
|
|
case 0:
|
||
|
|
if (m[i] == 0xff)
|
||
|
|
*sof_read = 1;
|
||
|
|
break;
|
||
|
|
case 1:
|
||
|
|
if (m[i] == 0xff)
|
||
|
|
*sof_read = 2;
|
||
|
|
else
|
||
|
|
*sof_read = 0;
|
||
|
|
break;
|
||
|
|
case 2:
|
||
|
|
switch (m[i]) {
|
||
|
|
case 0x00:
|
||
|
|
*sof_read = 3;
|
||
|
|
break;
|
||
|
|
case 0xff:
|
||
|
|
/* stay in this state */
|
||
|
|
break;
|
||
|
|
default:
|
||
|
|
*sof_read = 0;
|
||
|
|
}
|
||
|
|
break;
|
||
|
|
case 3:
|
||
|
|
if (m[i] == 0xff)
|
||
|
|
*sof_read = 4;
|
||
|
|
else
|
||
|
|
*sof_read = 0;
|
||
|
|
break;
|
||
|
|
case 4:
|
||
|
|
switch (m[i]) {
|
||
|
|
case 0x96:
|
||
|
|
/* Pattern found */
|
||
|
|
PDEBUG(D_FRAM,
|
||
|
|
"SOF found, bytes to analyze: %u."
|
||
|
|
" Frame starts at byte #%u",
|
||
|
|
len, i + 1);
|
||
|
|
*sof_read = 0;
|
||
|
|
return m + i + 1;
|
||
|
|
break;
|
||
|
|
case 0xff:
|
||
|
|
*sof_read = 2;
|
||
|
|
break;
|
||
|
|
default:
|
||
|
|
*sof_read = 0;
|
||
|
|
}
|
||
|
|
break;
|
||
|
|
default:
|
||
|
|
*sof_read = 0;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
return NULL;
|
||
|
|
}
|