diff options
author | Hans de Goede <j.w.r.degoede@hhs.nl> | 2008-09-04 00:12:14 +0400 |
---|---|---|
committer | Mauro Carvalho Chehab <mchehab@redhat.com> | 2008-09-04 01:37:24 +0400 |
commit | 327c4abf74a4426676df6c359b2a3dea2a5d126e (patch) | |
tree | 005359b56ee32e6dc645b57d0f0da518292719a8 /drivers/media | |
parent | 62ee8eeebd1bf6c29977800ac18dfcecf584d42e (diff) | |
download | linux-327c4abf74a4426676df6c359b2a3dea2a5d126e.tar.xz |
V4L/DVB (8812): gspca: Do pac73xx webcams work.
- documentation for some registers
- some preparations for adding autogain_n_exposure functionality
- various pac7311 fixes
- disable brightness and colors controls for 7311
- fix contrast control for 7311
- add hflip and vflip controls for 7311
- minimal jpeg header
- proper SOF detection
Signed-off-by: Hans de Goede <j.w.r.degoede@hhs.nl>
Signed-off-by: Jean-Francois Moine <moinejf@free.fr>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Diffstat (limited to 'drivers/media')
-rw-r--r-- | drivers/media/video/gspca/pac207.c | 36 | ||||
-rw-r--r-- | drivers/media/video/gspca/pac7311.c | 309 | ||||
-rw-r--r-- | drivers/media/video/gspca/pac_common.h | 53 |
3 files changed, 220 insertions, 178 deletions
diff --git a/drivers/media/video/gspca/pac207.c b/drivers/media/video/gspca/pac207.c index d9668f4cb4d1..620c9631629e 100644 --- a/drivers/media/video/gspca/pac207.c +++ b/drivers/media/video/gspca/pac207.c @@ -181,9 +181,6 @@ static const __u8 pac207_sensor_init[][8] = { /* 48 reg_72 Rate Control end BalSize_4a =0x36 */ static const __u8 PacReg72[] = { 0x00, 0x00, 0x36, 0x00 }; -static const unsigned char pac207_sof_marker[5] = - { 0xff, 0xff, 0x00, 0xff, 0x96 }; - static int pac207_write_regs(struct gspca_dev *gspca_dev, u16 index, const u8 *buffer, u16 length) { @@ -367,31 +364,8 @@ static void pac207_do_auto_gain(struct gspca_dev *gspca_dev) sd->autogain_ignore_frames = PAC207_AUTOGAIN_IGNORE_FRAMES; } -static unsigned char *pac207_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] == pac207_sof_marker[sd->sof_read]) { - sd->sof_read++; - if (sd->sof_read == sizeof(pac207_sof_marker)) { - PDEBUG(D_STREAM, - "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; -} +/* Include pac common sof detection functions */ +#include "pac_common.h" static void sd_pkt_scan(struct gspca_dev *gspca_dev, struct gspca_frame *frame, @@ -401,14 +375,14 @@ static void sd_pkt_scan(struct gspca_dev *gspca_dev, struct sd *sd = (struct sd *) gspca_dev; unsigned char *sof; - sof = pac207_find_sof(gspca_dev, data, len); + sof = pac_find_sof(gspca_dev, data, len); if (sof) { int n; /* finish decoding current frame */ n = sof - data; - if (n > sizeof pac207_sof_marker) - n -= sizeof pac207_sof_marker; + if (n > sizeof pac_sof_marker) + n -= sizeof pac_sof_marker; else n = 0; frame = gspca_frame_add(gspca_dev, LAST_PACKET, frame, diff --git a/drivers/media/video/gspca/pac7311.c b/drivers/media/video/gspca/pac7311.c index 4cc9379ee411..bed04cc9a584 100644 --- a/drivers/media/video/gspca/pac7311.c +++ b/drivers/media/video/gspca/pac7311.c @@ -19,10 +19,36 @@ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */ +/* Some documentation about various registers as determined by trial and error. + When the register addresses differ between the 7202 and the 7311 the 2 + different addresses are written as 7302addr/7311addr, when one of the 2 + addresses is a - sign that register description is not valid for the + matching IC. + + Register page 1: + + Address Description + -/0x08 Unknown compressor related, must always be 8 except when not + in 640x480 resolution and page 4 reg 2 <= 3 then set it to 9 ! + -/0x1b Auto white balance related, bit 0 is AWB enable (inverted) + bits 345 seem to toggle per color gains on/off (inverted) + 0x78 Global control, bit 6 controls the LED (inverted) + -/0x80 JPEG compression ratio ? Best not touched + + Register page 3/4: + + Address Description + 0x02 Clock divider 2-63, fps =~ 60 / val. Must be a multiple of 3 on + the 7302, so one of 3, 6, 9, ... + -/0x0f Master gain 1-245, low value = high gain + 0x10/- Master gain 0-31 + -/0x10 Another gain 0-15, limited influence (1-2x gain I guess) + 0x21 Bitfield: 0-1 unused, 2-3 vflip/hflip, 4-5 unknown, 6-7 unused +*/ + #define MODULE_NAME "pac7311" #include "gspca.h" -#include "jpeg.h" MODULE_AUTHOR("Thomas Kaiser thomas@kaiser-linux.li"); MODULE_DESCRIPTION("Pixart PAC7311"); @@ -32,25 +58,22 @@ MODULE_LICENSE("GPL"); struct sd { struct gspca_dev gspca_dev; /* !! must be the first item */ - int lum_sum; - atomic_t avg_lum; - atomic_t do_gain; - unsigned char brightness; unsigned char contrast; unsigned char colors; unsigned char autogain; __u8 hflip; __u8 vflip; - __u8 qindex; - - char tosof; /* number of bytes before next start of frame */ - signed char ag_cnt; -#define AG_CNT_START 13 __u8 sensor; #define SENSOR_PAC7302 0 #define SENSOR_PAC7311 1 + + u8 sof_read; + u8 header_read; + u8 autogain_ignore_frames; + + atomic_t avg_lum; }; /* V4L2 controls supported by the driver */ @@ -92,7 +115,7 @@ static struct ctrl sd_ctrls[] = { #define CONTRAST_MAX 255 .maximum = CONTRAST_MAX, .step = 1, -#define CONTRAST_DEF 60 +#define CONTRAST_DEF 127 .default_value = CONTRAST_DEF, }, .set = sd_setcontrast, @@ -243,7 +266,7 @@ static const __u8 start_7302[] = { 0x2a, 5, 0xc8, 0x00, 0x18, 0x12, 0x22, 0x64, 8, 0x00, 0x00, 0xf0, 0x01, 0x14, 0x44, 0x44, 0x44, 0x6e, 1, 0x08, - 0xff, 1, 0x03, /* page 1 */ + 0xff, 1, 0x01, /* page 1 */ 0x78, 1, 0x00, 0, 0 /* end of sequence */ }; @@ -274,9 +297,9 @@ static const __u8 page3_7302[] = { /* pac 7311 */ static const __u8 probe_7311[] = { - 0x78, 0x40, /* Bit_0=start stream, Bit_7=LED */ - 0x78, 0x40, /* Bit_0=start stream, Bit_7=LED */ - 0x78, 0x44, /* Bit_0=start stream, Bit_7=LED */ + 0x78, 0x40, /* Bit_0=start stream, Bit_6=LED */ + 0x78, 0x40, /* Bit_0=start stream, Bit_6=LED */ + 0x78, 0x44, /* Bit_0=start stream, Bit_6=LED */ 0xff, 0x04, 0x27, 0x80, 0x28, 0xca, @@ -340,18 +363,6 @@ static void reg_w_buf(struct gspca_dev *gspca_dev, 500); } -static __u8 reg_r(struct gspca_dev *gspca_dev, - __u8 index) -{ - usb_control_msg(gspca_dev->dev, - usb_rcvctrlpipe(gspca_dev->dev, 0), - 0, /* request */ - USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_DEVICE, - 0, /* value */ - index, gspca_dev->usb_buf, 1, - 500); - return gspca_dev->usb_buf[0]; -} static void reg_w(struct gspca_dev *gspca_dev, __u8 index, @@ -413,7 +424,7 @@ static void reg_w_var(struct gspca_dev *gspca_dev, reg_w_page(gspca_dev, page3_7302, sizeof page3_7302); break; default: - if (len > 32) { + if (len > 64) { PDEBUG(D_ERR|D_STREAM, "Incorrect variable sequence"); return; @@ -453,7 +464,7 @@ static int sd_config(struct gspca_dev *gspca_dev, cam->nmodes = 1; } else { PDEBUG(D_CONF, "Find Sensor PAC7311"); - reg_w_seq(gspca_dev, probe_7302, sizeof probe_7302); + reg_w_seq(gspca_dev, probe_7311, sizeof probe_7311); cam->cam_mode = vga_mode; cam->nmodes = ARRAY_SIZE(vga_mode); @@ -465,8 +476,6 @@ static int sd_config(struct gspca_dev *gspca_dev, sd->autogain = AUTOGAIN_DEF; sd->hflip = HFLIP_DEF; sd->vflip = VFLIP_DEF; - sd->qindex = 3; - sd->ag_cnt = -1; return 0; } @@ -497,6 +506,7 @@ static void setbrightcont(struct gspca_dev *gspca_dev) reg_w(gspca_dev, 0xdc, 0x01); } +/* This function is used by pac7302 only */ static void setbrightness(struct gspca_dev *gspca_dev) { struct sd *sd = (struct sd *) gspca_dev; @@ -506,7 +516,10 @@ static void setbrightness(struct gspca_dev *gspca_dev) setbrightcont(gspca_dev); return; } -/*jfm: inverted?*/ +/* HDG: this is not brightness but gain, I'll add gain and exposure controls + in a next patch */ + return; + brightness = BRIGHTNESS_MAX - sd->brightness; reg_w(gspca_dev, 0xff, 0x04); reg_w(gspca_dev, 0x0e, 0x00); @@ -524,12 +537,13 @@ static void setcontrast(struct gspca_dev *gspca_dev) setbrightcont(gspca_dev); return; } - reg_w(gspca_dev, 0xff, 0x01); - reg_w(gspca_dev, 0x10, sd->contrast); + reg_w(gspca_dev, 0xff, 0x04); + reg_w(gspca_dev, 0x10, sd->contrast >> 4); /* load registers to sensor (Bit 0, auto clear) */ reg_w(gspca_dev, 0x11, 0x01); } +/* This function is used by pac7302 only */ static void setcolors(struct gspca_dev *gspca_dev) { struct sd *sd = (struct sd *) gspca_dev; @@ -551,36 +565,24 @@ static void setcolors(struct gspca_dev *gspca_dev) reg_w(gspca_dev, 0x0f + 2 * i + 1, v); } reg_w(gspca_dev, 0xdc, 0x01); - return; + PDEBUG(D_CONF|D_STREAM, "color: %i", sd->colors); } - reg_w(gspca_dev, 0xff, 0x01); - reg_w(gspca_dev, 0x80, sd->colors); - /* load registers to sensor (Bit 0, auto clear) */ - reg_w(gspca_dev, 0x11, 0x01); - PDEBUG(D_CONF|D_STREAM, "color: %i", sd->colors); } -static void setautogain(struct gspca_dev *gspca_dev) -{ - struct sd *sd = (struct sd *) gspca_dev; - - if (sd->autogain) { - sd->lum_sum = 0; - sd->ag_cnt = AG_CNT_START; - } else { - sd->ag_cnt = -1; - } -} - -/* this function is used by pac7302 only */ static void sethvflip(struct gspca_dev *gspca_dev) { struct sd *sd = (struct sd *) gspca_dev; __u8 data; - reg_w(gspca_dev, 0xff, 0x03); /* page 3 */ - data = (sd->hflip ? 0x00 : 0x08) - | (sd->vflip ? 0x04 : 0x00); + if (sd->sensor == SENSOR_PAC7302) { + reg_w(gspca_dev, 0xff, 0x03); /* page 3 */ + data = (sd->hflip ? 0x00 : 0x08) + | (sd->vflip ? 0x04 : 0x00); + } else { + reg_w(gspca_dev, 0xff, 0x04); /* page 3 */ + data = (sd->hflip ? 0x04 : 0x00) + | (sd->vflip ? 0x08 : 0x00); + } reg_w(gspca_dev, 0x21, data); reg_w(gspca_dev, 0x11, 0x01); } @@ -588,7 +590,6 @@ static void sethvflip(struct gspca_dev *gspca_dev) /* this function is called at open time */ static int sd_open(struct gspca_dev *gspca_dev) { - reg_w(gspca_dev, 0x78, 0x44); /* Turn on LED */ return 0; } @@ -596,7 +597,7 @@ static void sd_start(struct gspca_dev *gspca_dev) { struct sd *sd = (struct sd *) gspca_dev; - sd->tosof = 0; + sd->sof_read = 0; if (sd->sensor == SENSOR_PAC7302) reg_w_var(gspca_dev, start_7302); @@ -606,7 +607,6 @@ static void sd_start(struct gspca_dev *gspca_dev) setcontrast(gspca_dev); setbrightness(gspca_dev); setcolors(gspca_dev); - setautogain(gspca_dev); /* set correct resolution */ switch (gspca_dev->cam.cam_mode[(int) gspca_dev->curr_mode].priv) { @@ -621,7 +621,7 @@ static void sd_start(struct gspca_dev *gspca_dev) break; case 1: /* 320x240 pac7311 */ reg_w(gspca_dev, 0xff, 0x04); - reg_w(gspca_dev, 0x02, 0x07); + reg_w(gspca_dev, 0x02, 0x03); reg_w(gspca_dev, 0xff, 0x01); reg_w(gspca_dev, 0x08, 0x09); reg_w(gspca_dev, 0x17, 0x30); @@ -650,6 +650,10 @@ static void sd_start(struct gspca_dev *gspca_dev) reg_w(gspca_dev, 0x78, 0x44); reg_w(gspca_dev, 0x78, 0x45); } + + sd->sof_read = 0; + sd->autogain_ignore_frames = 0; + atomic_set(&sd->avg_lum, -1); } static void sd_stopN(struct gspca_dev *gspca_dev) @@ -657,6 +661,7 @@ static void sd_stopN(struct gspca_dev *gspca_dev) struct sd *sd = (struct sd *) gspca_dev; if (sd->sensor == SENSOR_PAC7302) { + reg_w(gspca_dev, 0xff, 0x01); reg_w(gspca_dev, 0x78, 0x00); reg_w(gspca_dev, 0x78, 0x00); return; @@ -668,9 +673,9 @@ static void sd_stopN(struct gspca_dev *gspca_dev) reg_w(gspca_dev, 0x2a, 0x0e); reg_w(gspca_dev, 0xff, 0x01); reg_w(gspca_dev, 0x3e, 0x20); - reg_w(gspca_dev, 0x78, 0x44); /* Bit_0=start stream, Bit_7=LED */ - reg_w(gspca_dev, 0x78, 0x44); /* Bit_0=start stream, Bit_7=LED */ - reg_w(gspca_dev, 0x78, 0x44); /* Bit_0=start stream, Bit_7=LED */ + reg_w(gspca_dev, 0x78, 0x44); /* Bit_0=start stream, Bit_6=LED */ + reg_w(gspca_dev, 0x78, 0x44); /* Bit_0=start stream, Bit_6=LED */ + reg_w(gspca_dev, 0x78, 0x44); /* Bit_0=start stream, Bit_6=LED */ } static void sd_stop0(struct gspca_dev *gspca_dev) @@ -690,42 +695,22 @@ static void sd_close(struct gspca_dev *gspca_dev) static void do_autogain(struct gspca_dev *gspca_dev) { - struct sd *sd = (struct sd *) gspca_dev; - int luma; - int luma_mean = 128; - int luma_delta = 20; - __u8 spring = 5; - int Gbright; - - if (!atomic_read(&sd->do_gain)) - return; - atomic_set(&sd->do_gain, 0); - - luma = atomic_read(&sd->avg_lum); - Gbright = reg_r(gspca_dev, 0x02); - PDEBUG(D_FRAM, "luma mean %d", luma); - if (luma < luma_mean - luma_delta || - luma > luma_mean + luma_delta) { - Gbright += (luma_mean - luma) >> spring; - if (Gbright > 0x1a) - Gbright = 0x1a; - else if (Gbright < 4) - Gbright = 4; - PDEBUG(D_FRAM, "gbright %d", Gbright); - if (sd->sensor == SENSOR_PAC7302) { - reg_w(gspca_dev, 0xff, 0x03); - reg_w(gspca_dev, 0x10, Gbright); - /* load registers to sensor (Bit 0, auto clear) */ - reg_w(gspca_dev, 0x11, 0x01); - } else { - reg_w(gspca_dev, 0xff, 0x04); - reg_w(gspca_dev, 0x0f, Gbright); - /* load registers to sensor (Bit 0, auto clear) */ - reg_w(gspca_dev, 0x11, 0x01); - } - } } +static const unsigned char pac7311_jpeg_header1[] = { + 0xff, 0xd8, 0xff, 0xc0, 0x00, 0x11, 0x08 +}; + +static const unsigned char pac7311_jpeg_header2[] = { + 0x03, 0x01, 0x21, 0x00, 0x02, 0x11, 0x01, 0x03, 0x11, 0x01, 0xff, 0xda, + 0x00, 0x0c, 0x03, 0x01, 0x00, 0x02, 0x11, 0x03, 0x11, 0x00, 0x3f, 0x00 +}; + +/* Include pac common sof detection functions */ +#include "pac_common.h" + +#define HEADER_LENGTH 2 + /* this function is run at interrupt level */ static void sd_pkt_scan(struct gspca_dev *gspca_dev, struct gspca_frame *frame, /* target */ @@ -733,58 +718,89 @@ static void sd_pkt_scan(struct gspca_dev *gspca_dev, int len) /* iso packet length */ { struct sd *sd = (struct sd *) gspca_dev; - int i; - -#define INTER_FRAME 0x53 /* eof + inter frame + sof */ -#define LUM_OFFSET 0x1e /* reverse offset / start of frame */ - - /* - * inside a frame, there may be: - * escaped ff ('ff 00') - * sequences'ff ff ff xx' to remove - * end of frame ('ff d9') - * at the end of frame, there are: - * ff d9 end of frame - * 0x33 bytes - * one byte luminosity - * 0x16 bytes - * ff ff 00 ff 96 62 44 start of frame - */ - - if (sd->tosof != 0) { /* if outside a frame */ - - /* get the luminosity and go to the start of frame */ - data += sd->tosof; - len -= sd->tosof; - if (sd->tosof > LUM_OFFSET) - sd->lum_sum += data[-LUM_OFFSET]; - sd->tosof = 0; - jpeg_put_header(gspca_dev, frame, sd->qindex, 0x21); + unsigned char *sof; + + sof = pac_find_sof(gspca_dev, data, len); + if (sof) { + unsigned char tmpbuf[4]; + int n, lum_offset, footer_length; + + if (sd->sensor == SENSOR_PAC7302) { + lum_offset = 34 + sizeof pac_sof_marker; + footer_length = 74; + } else { + lum_offset = 24 + sizeof pac_sof_marker; + footer_length = 26; + } + + /* Finish decoding current frame */ + n = (sof - data) - (footer_length + sizeof pac_sof_marker); + if (n < 0) { + frame->data_end += n; + n = 0; + } + frame = gspca_frame_add(gspca_dev, INTER_PACKET, frame, + data, n); + if (gspca_dev->last_packet_type != DISCARD_PACKET && + frame->data_end[-2] == 0xff && + frame->data_end[-1] == 0xd9) + frame = gspca_frame_add(gspca_dev, LAST_PACKET, frame, + NULL, 0); + + n = sof - data; + len -= n; + data = sof; + + /* Get average lumination */ + if (gspca_dev->last_packet_type == LAST_PACKET && + n >= lum_offset) { + if (sd->sensor == SENSOR_PAC7302) + atomic_set(&sd->avg_lum, + (data[-lum_offset] << 8) | + data[-lum_offset + 1]); + else + atomic_set(&sd->avg_lum, + data[-lum_offset] + + data[-lum_offset + 1]); + } else { + atomic_set(&sd->avg_lum, -1); + } + + /* Start the new frame with the jpeg header */ + gspca_frame_add(gspca_dev, FIRST_PACKET, frame, + pac7311_jpeg_header1, sizeof(pac7311_jpeg_header1)); + if (sd->sensor == SENSOR_PAC7302) { + /* The PAC7302 has the image rotated 90 degrees */ + tmpbuf[0] = gspca_dev->width >> 8; + tmpbuf[1] = gspca_dev->width & 0xff; + tmpbuf[2] = gspca_dev->height >> 8; + tmpbuf[3] = gspca_dev->height & 0xff; + } else { + tmpbuf[0] = gspca_dev->height >> 8; + tmpbuf[1] = gspca_dev->height & 0xff; + tmpbuf[2] = gspca_dev->width >> 8; + tmpbuf[3] = gspca_dev->width & 0xff; + } + gspca_frame_add(gspca_dev, INTER_PACKET, frame, tmpbuf, 4); + gspca_frame_add(gspca_dev, INTER_PACKET, frame, + pac7311_jpeg_header2, sizeof(pac7311_jpeg_header2)); + + sd->header_read = 0; } - for (i = 0; i < len; i++) { - if (data[i] != 0xff) - continue; - switch (data[i + 1]) { - case 0xd9: /* 'ff d9' end of frame */ - frame = gspca_frame_add(gspca_dev, - LAST_PACKET, - frame, data, i + 2); - data += i + INTER_FRAME; - len -= i + INTER_FRAME; - i = 0; - if (len > -LUM_OFFSET) - sd->lum_sum += data[-LUM_OFFSET]; - if (len < 0) { - sd->tosof = -len; - break; - } - jpeg_put_header(gspca_dev, frame, sd->qindex, 0x21); - break; + if (sd->header_read < HEADER_LENGTH) { + /* skip the variable part of the sof header */ + int needed = HEADER_LENGTH - sd->header_read; + if (len <= needed) { + sd->header_read += len; + return; } + data += needed; + len -= needed; + sd->header_read = HEADER_LENGTH; } - gspca_frame_add(gspca_dev, INTER_PACKET, - frame, data, i); + + gspca_frame_add(gspca_dev, INTER_PACKET, frame, data, len); } static int sd_setbrightness(struct gspca_dev *gspca_dev, __s32 val) @@ -846,8 +862,7 @@ static int sd_setautogain(struct gspca_dev *gspca_dev, __s32 val) struct sd *sd = (struct sd *) gspca_dev; sd->autogain = val; - if (gspca_dev->streaming) - setautogain(gspca_dev); + return 0; } diff --git a/drivers/media/video/gspca/pac_common.h b/drivers/media/video/gspca/pac_common.h new file mode 100644 index 000000000000..a19b5d44c009 --- /dev/null +++ b/drivers/media/video/gspca/pac_common.h @@ -0,0 +1,53 @@ +/* + * 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 + * + */ + +static const unsigned char pac_sof_marker[5] = + { 0xff, 0xff, 0x00, 0xff, 0x96 }; + +static unsigned char *pac_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] == pac_sof_marker[sd->sof_read]) { + sd->sof_read++; + if (sd->sof_read == sizeof(pac_sof_marker)) { + PDEBUG(D_STREAM, + "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; +} |