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| author | Jean-Francois Moine <moinejf@free.fr> | 2008-08-31 08:07:44 +0200 |
|---|---|---|
| committer | Jean-Francois Moine <moinejf@free.fr> | 2008-08-31 08:07:44 +0200 |
| commit | f1a52a2e70204db19b6c81bb59de2c759cefaaa6 (patch) | |
| tree | 882adbd278eafe5ceacdb3f9ea935350706f472f | |
| parent | aa7b59a4ff3c24effe6d63cc0a0694f5c33234dc (diff) | |
| download | mediapointer-dvb-s2-f1a52a2e70204db19b6c81bb59de2c759cefaaa6.tar.gz mediapointer-dvb-s2-f1a52a2e70204db19b6c81bb59de2c759cefaaa6.tar.bz2 | |
gspca: Fix dark room problem with sonixb.
From: Hans de Goede <j.w.r.degoede@hhs.nl>
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.
Priority: high
Signed-off-by: Hans de Goede <j.w.r.degoede@hhs.nl>
Signed-off-by: Jean-Francois Moine <moinejf@free.fr>
| -rw-r--r-- | linux/drivers/media/video/gspca/sonixb.c | 14 |
1 files changed, 12 insertions, 2 deletions
diff --git a/linux/drivers/media/video/gspca/sonixb.c b/linux/drivers/media/video/gspca/sonixb.c index 0cb12acf9..5b02da8a4 100644 --- a/linux/drivers/media/video/gspca/sonixb.c +++ b/linux/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; @@ -1052,10 +1053,19 @@ 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) { |