| Hans de Goede | 327c4ab | 2008-09-03 17:12:14 -0300 | [diff] [blame] | 1 | /* |
| 2 | * Pixart PAC207BCA / PAC73xx common functions |
| 3 | * |
| 4 | * Copyright (C) 2008 Hans de Goede <j.w.r.degoede@hhs.nl> |
| 5 | * Copyright (C) 2005 Thomas Kaiser thomas@kaiser-linux.li |
| 6 | * Copyleft (C) 2005 Michel Xhaard mxhaard@magic.fr |
| 7 | * |
| 8 | * V4L2 by Jean-Francois Moine <http://moinejf.free.fr> |
| 9 | * |
| 10 | * This program is free software; you can redistribute it and/or modify |
| 11 | * it under the terms of the GNU General Public License as published by |
| 12 | * the Free Software Foundation; either version 2 of the License, or |
| 13 | * (at your option) any later version. |
| 14 | * |
| 15 | * This program is distributed in the hope that it will be useful, |
| 16 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 17 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 18 | * GNU General Public License for more details. |
| 19 | * |
| 20 | * You should have received a copy of the GNU General Public License |
| 21 | * along with this program; if not, write to the Free Software |
| 22 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
| 23 | * |
| 24 | */ |
| 25 | |
| Hans de Goede | 8a5b2e9 | 2008-09-03 17:12:17 -0300 | [diff] [blame] | 26 | /* We calculate the autogain at the end of the transfer of a frame, at this |
| 27 | moment a frame with the old settings is being transmitted, and a frame is |
| 28 | being captured with the old settings. So if we adjust the autogain we must |
| 29 | ignore atleast the 2 next frames for the new settings to come into effect |
| 30 | before doing any other adjustments */ |
| 31 | #define PAC_AUTOGAIN_IGNORE_FRAMES 3 |
| 32 | |
| Hans de Goede | 327c4ab | 2008-09-03 17:12:14 -0300 | [diff] [blame] | 33 | static const unsigned char pac_sof_marker[5] = |
| 34 | { 0xff, 0xff, 0x00, 0xff, 0x96 }; |
| 35 | |
| 36 | static unsigned char *pac_find_sof(struct gspca_dev *gspca_dev, |
| 37 | unsigned char *m, int len) |
| 38 | { |
| 39 | struct sd *sd = (struct sd *) gspca_dev; |
| 40 | int i; |
| 41 | |
| 42 | /* Search for the SOF marker (fixed part) in the header */ |
| 43 | for (i = 0; i < len; i++) { |
| 44 | if (m[i] == pac_sof_marker[sd->sof_read]) { |
| 45 | sd->sof_read++; |
| 46 | if (sd->sof_read == sizeof(pac_sof_marker)) { |
| Hans de Goede | 8a5b2e9 | 2008-09-03 17:12:17 -0300 | [diff] [blame] | 47 | PDEBUG(D_FRAM, |
| Hans de Goede | 327c4ab | 2008-09-03 17:12:14 -0300 | [diff] [blame] | 48 | "SOF found, bytes to analyze: %u." |
| 49 | " Frame starts at byte #%u", |
| 50 | len, i + 1); |
| 51 | sd->sof_read = 0; |
| 52 | return m + i + 1; |
| 53 | } |
| 54 | } else { |
| 55 | sd->sof_read = 0; |
| 56 | } |
| 57 | } |
| 58 | |
| 59 | return NULL; |
| 60 | } |