61 строка
2.0 KiB
C
61 строка
2.0 KiB
C
/*
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* Pixart PAC207BCA / PAC73xx common functions
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*
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* Copyright (C) 2008 Hans de Goede <j.w.r.degoede@hhs.nl>
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* Copyright (C) 2005 Thomas Kaiser thomas@kaiser-linux.li
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* Copyleft (C) 2005 Michel Xhaard mxhaard@magic.fr
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*
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* V4L2 by Jean-Francois Moine <http://moinejf.free.fr>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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*
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*/
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/* We calculate the autogain at the end of the transfer of a frame, at this
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moment a frame with the old settings is being transmitted, and a frame is
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being captured with the old settings. So if we adjust the autogain we must
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ignore atleast the 2 next frames for the new settings to come into effect
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before doing any other adjustments */
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#define PAC_AUTOGAIN_IGNORE_FRAMES 3
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static const unsigned char pac_sof_marker[5] =
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{ 0xff, 0xff, 0x00, 0xff, 0x96 };
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static unsigned char *pac_find_sof(struct gspca_dev *gspca_dev,
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unsigned char *m, int len)
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{
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struct sd *sd = (struct sd *) gspca_dev;
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int i;
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/* Search for the SOF marker (fixed part) in the header */
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for (i = 0; i < len; i++) {
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if (m[i] == pac_sof_marker[sd->sof_read]) {
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sd->sof_read++;
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if (sd->sof_read == sizeof(pac_sof_marker)) {
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PDEBUG(D_FRAM,
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"SOF found, bytes to analyze: %u."
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" Frame starts at byte #%u",
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len, i + 1);
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sd->sof_read = 0;
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return m + i + 1;
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}
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} else {
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sd->sof_read = 0;
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}
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}
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return NULL;
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}
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