Hi Philipp, Krzysztof,
On 06/15/2018 01:33 AM, Krzysztof Hałasa wrote:
Steve Longerbeam <slongerbeam@xxxxxxxxx> writes:
Right, the selection of interweave is moved to the capture devices,
so the following will enable interweave:
v4l2-ctl -dN --set-fmt-video=field=interlaced_tb
and
So the patch to adv7180 needs to be modified to report # field lines.
Try the following:
--- a/drivers/media/i2c/adv7180.c
+++ b/drivers/media/i2c/adv7180.c
With this patch, fix-csi-interlaced.3 seems to work for me.
"ipu2_csi1":2 reports [fmt:AYUV32/720x576 field:seq-tb], but the
/dev/videoX shows (when requested) 720 x 576 NV12 interlaced, top field
first, and I'm getting valid output.
Thanks for your work.
I've found some time to diagnose the behavior of interweave with B/T line
swapping (to support interlaced-bt) with planar formats.
There are a couple problems (one known and one unknown):
1. This requires 32 pixel alignment to meet the IDMAC 8-byte alignment
of the planar U/V buffer offsets, and 32 pixel alignment precludes
capturing raw NTSC/PAL at 720 pixel line stride.
2. Even with 32 pixel aligned frames, for example by using the prpenc scaler
to generate 704 pixel strides from 720, the colors are still wrong when
capturing interlaced-bt. I thought for sure this must be because we
also
need to double the SLUV line strides in addition to doubling SLY
line stride.
But I tried this and the results are that it works only for YUV
4:2:2. For 4:2:0
it causes system hard lockups. (Aside note: interweave without line
swap
apparently has never worked for 4:2:2, even when doubling SLUV, so it's
quite bizarre to me why 4:2:2 interweave _with_ line swap _does_ work
after doubling SLUV).
For these reasons I think we should disallow interlaced-bt with planar
formats.
If the user needs NTSC interlaced capture with planar, the fields can be
swapped at
the CSI, by selecting seq-tb at the CSI source pad, which allows for
interlaced-tb
at the capture interface, which doesn't require interweave line swapping.
Steve
