Changes between Version 17 and Version 18 of linux/media


Ignore:
Timestamp:
06/19/2020 12:00:39 AM (2 years ago)
Author:
Tim Harvey
Comment:

remove reference to kernel version

Legend:

Unmodified
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  • linux/media

    v17 v18  
    307307Note that it is required that you re-run the {{{media-ctl-setup}}} script and its generated output commands whenever the input source changes (ie Analog NTSC->PAL or HDMI input format (resolution/colorspace/framerate).
    308308
    309 Note that for many Analog decoder chips such as the adv7180 used on Ventana you must stop and re-start streaming if you lose or gain signal lock (ie Analog video input is disconnected and reconnected or simply connected after streaming starts). This is because many analog video decoders end up producing some incomplete frames right after lock and these frames must be discarded or they will confuse the IMX6. There is no support for discarding the first few frames in mainline linux at this time, but you can use the following patch which is included in Gateworks 4.20 media kernel: https://github.com/Gateworks/linux-imx6/commit/fcab532
     309Note that for many Analog decoder chips such as the adv7180 used on Ventana you must stop and re-start streaming if you lose or gain signal lock (ie Analog video input is disconnected and reconnected or simply connected after streaming starts). This is because many analog video decoders end up producing some incomplete frames right after lock and these frames must be discarded or they will confuse the IMX6. There is no support for discarding the first few frames in mainline linux at this time, but you can use the following patch which is included in Gateworks media kernel: https://github.com/Gateworks/linux-imx6/commit/fcab532
    310310
    311311To detect when the input changes on a capture source you can catch the {{{V4L2_EVENT_SOURCE_CHANGE}}} event via the {{{VIDIOC_DQEVENT}}} ioctl - see https://www.linuxtv.org/downloads/v4l-dvb-apis-old/vidioc-dqevent.html