[PATCH 15/28] V4L/DVB (4983): Force temporal filter to 0 whenscaling to prevent ghosting.

From: Mauro Carvalho Chehab
Date: Wed Dec 27 2006 - 12:18:20 EST



From: Hans Verkuil <hverkuil@xxxxxxxxx>

Change the code to unconditionally turn off the temporal filter when scaling.
If the window is not full screen the filter will introduce a nasty ghosting
effect.

Signed-off-by: Hans Verkuil <hverkuil@xxxxxxxxx>
Signed-off-by: Mauro Carvalho Chehab <mchehab@xxxxxxxxxxxxx>
---

drivers/media/video/cx2341x.c | 15 ++++++---------
1 files changed, 6 insertions(+), 9 deletions(-)

diff --git a/drivers/media/video/cx2341x.c b/drivers/media/video/cx2341x.c
index 657e0b9..e796afd 100644
--- a/drivers/media/video/cx2341x.c
+++ b/drivers/media/video/cx2341x.c
@@ -742,7 +742,6 @@ int cx2341x_update(void *priv, cx2341x_m

if (old == NULL || old->width != new->width || old->height != new->height ||
old->video_encoding != new->video_encoding) {
- int is_scaling;
u16 w = new->width;
u16 h = new->height;

@@ -752,20 +751,18 @@ int cx2341x_update(void *priv, cx2341x_m
}
err = cx2341x_api(priv, func, CX2341X_ENC_SET_FRAME_SIZE, 2, h, w);
if (err) return err;
+ }

+ if (new->width != 720 || new->height != (new->is_50hz ? 576 : 480)) {
/* Adjust temporal filter if necessary. The problem with the temporal
filter is that it works well with full resolution capturing, but
not when the capture window is scaled (the filter introduces
- a ghosting effect). So if the capture window changed, and there is
- no updated filter value, then the filter is set depending on whether
- the new window is full resolution or not.
+ a ghosting effect). So if the capture window is scaled, then
+ force the filter to 0.

- For full resolution a setting of 8 really improves the video
+ For full resolution the filter really improves the video
quality, especially if the original video quality is suboptimal. */
- is_scaling = new->width != 720 || new->height != (new->is_50hz ? 576 : 480);
- if (old && old->video_temporal_filter == temporal) {
- temporal = is_scaling ? 0 : 8;
- }
+ temporal = 0;
}

if (old == NULL || old->stream_type != new->stream_type) {

-
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