On 05/28/2018 12:59 AM, Ian Arkver wrote:
On 28/05/18 08:00, Philipp Zabel wrote:
On Fri, 2018-05-25 at 16:53 -0700, Steve Longerbeam wrote:
Interlaced scan, a.k.a. interweave, should be enabled at the CSI IDMAC
output pad if the input field type is 'alternate' (in addition to field
types 'seq-tb' and 'seq-bt').
Which brings up whether V4L2_FIELD_HAS_BOTH() macro should be used
to determine enabling interlaced/interweave scan. That macro
includes the 'interlaced' field types, and in those cases the data
is already interweaved with top/bottom field lines. A heads-up for
now that this if statement may need to call V4L2_FIELD_IS_SEQUENTIAL()
instead, I have no sensor hardware that sends 'interlaced' data, so
can't
test.
I agree, the check here should be IS_SEQUENTIAL || ALTERNATE, and
interlaced_scan should also be enabled if image.pix.field is
INTERLACED_TB/BT.
Yep, in fact I have implemented that in v2. Interlace_scan will be enabled
only if input field type is SEQUENTIAL || ALTERNATE, and output field type
is INTERLACED_TB/BT or non-qualified INTERLACED.
And for INTERLACED_TB/BT input, the logic should be inverted: then we'd
have to enable interlaced_scan whenever image.pix.field is SEQ_BT/TB.
Hi Philipp,
If your intent here is to de-interweave the two fields back to two
sequential fields, I don't believe the IDMAC operation would achieve
that. It's basically line stride doubling and a line offset for the
lines in the 2nd half of the incoming frame, right?
I agree, I'm not sure interlaced_scan will perform the inverse (turn an
interlaced
buffer into a sequential buffer). If the implementation involves a scan of
two lines, second line with a memory offset equal to field size, and
doubling
the line stride to reach the next set of two lines, then running that
operation
on an interlaced buffer would not produce a sequential buffer.
Steve
Signed-off-by: Steve Longerbeam <steve_longerbeam@xxxxxxxxxx>
---
drivers/staging/media/imx/imx-media-csi.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/staging/media/imx/imx-media-csi.c
b/drivers/staging/media/imx/imx-media-csi.c
index 9bc555c..eef3483 100644
--- a/drivers/staging/media/imx/imx-media-csi.c
+++ b/drivers/staging/media/imx/imx-media-csi.c
@@ -477,7 +477,8 @@ static int csi_idmac_setup_channel(struct
csi_priv *priv)
ipu_smfc_set_burstsize(priv->smfc, burst_size);
if (image.pix.field == V4L2_FIELD_NONE &&
- V4L2_FIELD_HAS_BOTH(infmt->field))
+ (V4L2_FIELD_HAS_BOTH(infmt->field) ||
+ infmt->field == V4L2_FIELD_ALTERNATE))
ipu_cpmem_interlaced_scan(priv->idmac_ch,
image.pix.bytesperline);
