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Commit ba24b442 authored by Hans Verkuil's avatar Hans Verkuil Committed by Mauro Carvalho Chehab
Browse files

[media] vivid: do not allow video loopback for SEQ_TB/BT 



Sequential top-bottom/bottom-top fields are not supported as video loopback.
This is too much work to implement for field settings that are rarely used.

Signed-off-by: default avatarHans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: default avatarMauro Carvalho Chehab <mchehab@osg.samsung.com>
parent 9c35bd48

Documentation/video4linux/vivid.txt

+5 −0
Original line number Diff line number Diff line
@@ -912,6 +912,11 @@ looped to the video input provided that: 
  sequence and field counting in struct v4l2_buffer on the capture side may not

  be 100% accurate.



- field settings V4L2_FIELD_SEQ_TB/BT are not supported. While it is possible to

  implement this, it would mean a lot of work to get this right. Since these

  field values are rarely used the decision was made not to implement this for

  now.



- on the input side the "Standard Signal Mode" for the S-Video input or the

  "DV Timings Signal Mode" for the HDMI input should be configured so that a

  valid signal is passed to the video input.

drivers/media/platform/vivid/vivid-vid-common.c

+7 −0
Original line number Diff line number Diff line
@@ -210,6 +210,13 @@ bool vivid_vid_can_loop(struct vivid_dev *dev) 
		return false;

	if (dev->field_cap != dev->field_out)

		return false;

	/*

	 * While this can be supported, it is just too much work

	 * to actually implement.

	 */

	if (dev->field_cap == V4L2_FIELD_SEQ_TB ||

	    dev->field_cap == V4L2_FIELD_SEQ_BT)

		return false;

	if (vivid_is_svid_cap(dev) && vivid_is_svid_out(dev)) {

		if (!(dev->std_cap & V4L2_STD_525_60) !=

		    !(dev->std_out & V4L2_STD_525_60))