projects / linux-2.6-block.git / blame
| Commit | Line | Data |
|---|---|---|
| c942fddf | 1 | /* SPDX-License-Identifier: GPL-2.0-or-later */ |
| 5bdd00b9 TK |
2 | /* |
| 3 | * SN9C2028 common functions | |
| 4 | * | |
| 5 | * Copyright (C) 2009 Theodore Kilgore <kilgota@auburn,edu> | |
| 6 | * | |
| 7 | * Based closely upon the file gspca/pac_common.h | |
| 5bdd00b9 TK |
8 | */ |
| 9 | ||
| d8fd9f56 VK |
10 | static const unsigned char sn9c2028_sof_marker[] = { |
| 11 | 0xff, 0xff, 0x00, 0xc4, 0xc4, 0x96, | |
| 12 | 0x00, | |
| 13 | 0x00, /* seq */ | |
| 14 | 0x00, | |
| 15 | 0x00, | |
| 16 | 0x00, /* avg luminance lower 8 bit */ | |
| 17 | 0x00, /* avg luminance higher 8 bit */ | |
| 18 | }; | |
| 5bdd00b9 TK |
19 | |
| 20 | static unsigned char *sn9c2028_find_sof(struct gspca_dev *gspca_dev, | |
| 21 | unsigned char *m, int len) | |
| 22 | { | |
| 23 | struct sd *sd = (struct sd *) gspca_dev; | |
| 24 | int i; | |
| 25 | ||
| 26 | /* Search for the SOF marker (fixed part) in the header */ | |
| 27 | for (i = 0; i < len; i++) { | |
| d8fd9f56 VK |
28 | if ((m[i] == sn9c2028_sof_marker[sd->sof_read]) || |
| 29 | (sd->sof_read > 5)) { | |
| 5bdd00b9 | 30 | sd->sof_read++; |
| d8fd9f56 VK |
31 | if (sd->sof_read == 11) |
| 32 | sd->avg_lum_l = m[i]; | |
| 33 | if (sd->sof_read == 12) | |
| 34 | sd->avg_lum = (m[i] << 8) + sd->avg_lum_l; | |
| 5bdd00b9 | 35 | if (sd->sof_read == sizeof(sn9c2028_sof_marker)) { |
| 37d5efb0 JP |
36 | gspca_dbg(gspca_dev, D_FRAM, |
| 37 | "SOF found, bytes to analyze: %u - Frame starts at byte #%u\n", | |
| 38 | len, i + 1); | |
| 5bdd00b9 TK |
39 | sd->sof_read = 0; |
| 40 | return m + i + 1; | |
| 41 | } | |
| 42 | } else { | |
| 43 | sd->sof_read = 0; | |
| 44 | } | |
| 45 | } | |
| 46 | ||
| 47 | return NULL; | |
| 48 | } |