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Diffstat (limited to 'Documentation/media/uapi/v4l/vidioc-dqevent.rst')
| -rw-r--r-- | Documentation/media/uapi/v4l/vidioc-dqevent.rst | 12 |
1 files changed, 11 insertions, 1 deletions
diff --git a/Documentation/media/uapi/v4l/vidioc-dqevent.rst b/Documentation/media/uapi/v4l/vidioc-dqevent.rst index cb3565f36793..04416b6943c0 100644 --- a/Documentation/media/uapi/v4l/vidioc-dqevent.rst +++ b/Documentation/media/uapi/v4l/vidioc-dqevent.rst @@ -379,7 +379,17 @@ call. - 0x0001 - This event gets triggered when a resolution change is detected at an input. This can come from an input connector or from a video - decoder. + decoder. Applications will have to query the new resolution (if + any, the signal may also have been lost). + + *Important*: even if the new video timings appear identical to the old + ones, receiving this event indicates that there was an issue with the + video signal and you must stop and restart streaming + (:ref:`VIDIOC_STREAMOFF <VIDIOC_STREAMON>` + followed by :ref:`VIDIOC_STREAMON <VIDIOC_STREAMON>`). The reason is + that many devices are not able to recover from a temporary loss of + signal and so restarting streaming I/O is required in order for the + hardware to synchronize to the video signal. Return Value |