diff options
| author | Hans de Goede <j.w.r.degoede@hhs.nl> | 2008-09-04 16:22:56 -0300 |
|---|---|---|
| committer | Mauro Carvalho Chehab <mchehab@redhat.com> | 2008-09-04 16:22:56 -0300 |
| commit | bf2a2202f75cda679303f09d150f9549f9835953 (patch) | |
| tree | 5f5d6b2466e573b920fffa83c5d3eff1f59346d1 /drivers/media/video | |
| parent | a94a508691d16420ad10572a33db4d45115b5f75 (diff) | |
V4L/DVB (8870): gspca: Fix dark room problem with sonixb.
When using the sonixb driver in a dark room and given that the autoexposure
algorithm starts with a setting most suitable for daylight, the picture
produced by the cam may actually be 100% black leading to a avg_lum value of 0,
so an avg_lum value of 0 does not always signal an exposure settings change
(which it normally does). This patch adds a check for the really black image
case and stops dropping all frames as invalid in this case.
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/video')
| -rw-r--r-- | drivers/media/video/gspca/sonixb.c | 14 |
1 files changed, 12 insertions, 2 deletions
diff --git a/drivers/media/video/gspca/sonixb.c b/drivers/media/video/gspca/sonixb.c index bde9ea9b980..64bc758fbae 100644 --- a/drivers/media/video/gspca/sonixb.c +++ b/drivers/media/video/gspca/sonixb.c @@ -52,6 +52,7 @@ MODULE_LICENSE("GPL"); struct sd { struct gspca_dev gspca_dev; /* !! must be the first item */ atomic_t avg_lum; + int prev_avg_lum; unsigned char gain; unsigned char exposure; @@ -1022,10 +1023,19 @@ static void sd_pkt_scan(struct gspca_dev *gspca_dev, } else { lum = data[i + 8] + (data[i + 9] << 8); } - if (lum == 0) { + /* When exposure changes midway a frame we + get a lum of 0 in this case drop 2 frames + as the frames directly after an exposure + change have an unstable image. Sometimes lum + *really* is 0 (cam used in low light with + low exposure setting), so do not drop frames + if the previous lum was 0 too. */ + if (lum == 0 && sd->prev_avg_lum != 0) { lum = -1; sd->frames_to_drop = 2; - } + sd->prev_avg_lum = 0; + } else + sd->prev_avg_lum = lum; atomic_set(&sd->avg_lum, lum); if (sd->frames_to_drop) { |