Autogain algorithm is very simple, if average luminance is low - increase gain,
if it's high - decrease gain. Gain granularity is low enough for this algo to
stabilize quickly.
Signed-off-by: Vasily Khoruzhick <anarsoul@xxxxxxxxx>
---
drivers/media/usb/gspca/sn9c2028.c | 121 +++++++++++++++++++++++++++++++++++++
drivers/media/usb/gspca/sn9c2028.h | 20 +++++-
2 files changed, 138 insertions(+), 3 deletions(-)
diff --git a/drivers/media/usb/gspca/sn9c2028.c b/drivers/media/usb/gspca/sn9c2028.c
index 317b02c..0ff390f 100644
--- a/drivers/media/usb/gspca/sn9c2028.c
+++ b/drivers/media/usb/gspca/sn9c2028.c
@@ -34,6 +34,16 @@ struct sd {
struct gspca_dev gspca_dev; /* !! must be the first item */
u8 sof_read;
u16 model;
+
+#define MIN_AVG_LUM 8500
+#define MAX_AVG_LUM 10000
+ int avg_lum;
+ u8 avg_lum_l;
+
+ struct { /* autogain and gain control cluster */
+ struct v4l2_ctrl *autogain;
+ struct v4l2_ctrl *gain;
+ };
};
struct init_command {
@@ -252,6 +262,77 @@ static int run_start_commands(struct gspca_dev *gspca_dev,
return 0;
}
+static void set_gain(struct gspca_dev *gspca_dev, s32 g)
+{
+ struct sd *sd = (struct sd *) gspca_dev;
+
+ struct init_command genius_vcam_live_gain_cmds[] = {
+ {{0x1d, 0x25, 0x10, 0x20, 0xab, 0x00}, 0},
+ };
+ if (!gspca_dev->streaming)
+ return;
+
+ switch (sd->model) {
+ case 0x7003:
+ genius_vcam_live_gain_cmds[0].instruction[2] = g;
+ run_start_commands(gspca_dev, genius_vcam_live_gain_cmds,
+ ARRAY_SIZE(genius_vcam_live_gain_cmds));
+ break;
+ default:
+ break;
+ }
+}
+
+static int sd_s_ctrl(struct v4l2_ctrl *ctrl)
+{
+ struct gspca_dev *gspca_dev =
+ container_of(ctrl->handler, struct gspca_dev, ctrl_handler);
+ struct sd *sd = (struct sd *)gspca_dev;
+
+ gspca_dev->usb_err = 0;
+
+ if (!gspca_dev->streaming)
+ return 0;
+
+ switch (ctrl->id) {
+ /* standalone gain control */
+ case V4L2_CID_GAIN:
+ set_gain(gspca_dev, ctrl->val);
+ break;
+ /* autogain */
+ case V4L2_CID_AUTOGAIN:
+ set_gain(gspca_dev, sd->gain->val);
+ break;
+ }
+ return gspca_dev->usb_err;
+}
+
+static const struct v4l2_ctrl_ops sd_ctrl_ops = {
+ .s_ctrl = sd_s_ctrl,
+};
+
+
+static int sd_init_controls(struct gspca_dev *gspca_dev)
+{
+ struct v4l2_ctrl_handler *hdl = &gspca_dev->ctrl_handler;
+ struct sd *sd = (struct sd *)gspca_dev;
+
+ gspca_dev->vdev.ctrl_handler = hdl;
+ v4l2_ctrl_handler_init(hdl, 2);
+
+ switch (sd->model) {
+ case 0x7003:
+ sd->gain = v4l2_ctrl_new_std(hdl, &sd_ctrl_ops,
+ V4L2_CID_GAIN, 0, 20, 1, 0);
+ sd->autogain = v4l2_ctrl_new_std(hdl, &sd_ctrl_ops,
+ V4L2_CID_AUTOGAIN, 0, 1, 1, 1);
+ break;
+ default:
+ break;
+ }
+
+ return 0;
+}
static int start_spy_cam(struct gspca_dev *gspca_dev)
{
struct init_command spy_start_commands[] = {
@@ -641,6 +722,9 @@ static int start_genius_videocam_live(struct gspca_dev *gspca_dev)
if (r < 0)
return r;
+ if (sd->gain)
+ set_gain(gspca_dev, v4l2_ctrl_g_ctrl(sd->gain));
+
return r;
}
@@ -757,6 +841,8 @@ static int sd_start(struct gspca_dev *gspca_dev)
return -ENXIO;
}
+ sd->avg_lum = -1;
+
return err_code;
}
@@ -776,6 +862,39 @@ static void sd_stopN(struct gspca_dev *gspca_dev)
PERR("Camera Stop command failed");
}
+static void do_autogain(struct gspca_dev *gspca_dev, int avg_lum)
+{
+ struct sd *sd = (struct sd *) gspca_dev;
+ s32 cur_gain = v4l2_ctrl_g_ctrl(sd->gain);
+
+ if (avg_lum == -1)
+ return;
+
+ if (avg_lum < MIN_AVG_LUM) {
+ if (cur_gain == sd->gain->maximum)
+ return;
+ cur_gain++;
+ v4l2_ctrl_s_ctrl(sd->gain, cur_gain);
+ }
+ if (avg_lum > MAX_AVG_LUM) {
+ if (cur_gain == sd->gain->minimum)
+ return;
+ cur_gain--;
+ v4l2_ctrl_s_ctrl(sd->gain, cur_gain);
+ }
+
+}
+
+static void sd_dqcallback(struct gspca_dev *gspca_dev)
+{
+ struct sd *sd = (struct sd *) gspca_dev;
+
+ if (sd->autogain == NULL || !v4l2_ctrl_g_ctrl(sd->autogain))
+ return;
+
+ do_autogain(gspca_dev, sd->avg_lum);
+}
+
/* Include sn9c2028 sof detection functions */
#include "sn9c2028.h"
@@ -810,8 +929,10 @@ static const struct sd_desc sd_desc = {
.name = MODULE_NAME,
.config = sd_config,
.init = sd_init,
+ .init_controls = sd_init_controls,
.start = sd_start,
.stopN = sd_stopN,
+ .dq_callback = sd_dqcallback,
.pkt_scan = sd_pkt_scan,
};
diff --git a/drivers/media/usb/gspca/sn9c2028.h b/drivers/media/usb/gspca/sn9c2028.h
index 8fd1d3e..6f20c0f 100644
--- a/drivers/media/usb/gspca/sn9c2028.h
+++ b/drivers/media/usb/gspca/sn9c2028.h
@@ -21,8 +21,17 @@
*
*/
-static const unsigned char sn9c2028_sof_marker[5] =
- { 0xff, 0xff, 0x00, 0xc4, 0xc4 };
+static const unsigned char sn9c2028_sof_marker[] = {
+ 0xff, 0xff, 0x00, 0xc4, 0xc4, 0x96,
+ 0x00,
+ 0x00, /* seq */
+ 0x00,
+ 0x00,
+ 0x00, /* avg luminance lower 8 bit */
+ 0x00, /* avg luminance higher 8 bit */
+ 0x00,
+ 0x00,
+};
static unsigned char *sn9c2028_find_sof(struct gspca_dev *gspca_dev,
unsigned char *m, int len)
@@ -32,8 +41,13 @@ static unsigned char *sn9c2028_find_sof(struct gspca_dev *gspca_dev,
/* Search for the SOF marker (fixed part) in the header */
for (i = 0; i < len; i++) {
- if (m[i] == sn9c2028_sof_marker[sd->sof_read]) {
+ if ((m[i] == sn9c2028_sof_marker[sd->sof_read]) ||
+ (sd->sof_read > 5)) {
sd->sof_read++;
+ if (sd->sof_read == 11)
+ sd->avg_lum_l = m[i];
+ if (sd->sof_read == 12)
+ sd->avg_lum = (m[i] << 8) + sd->avg_lum_l;
if (sd->sof_read == sizeof(sn9c2028_sof_marker)) {
PDEBUG(D_FRAM,
"SOF found, bytes to analyze: %u."
--
2.3.5
