Changes between Version 9 and Version 10 of linux/media


Ignore:
Timestamp:
06/05/2019 10:40:40 PM (6 weeks ago)
Author:
Tim Harvey
Comment:

fix typo and added note about adv7180 rolling

Legend:

Unmodified
Added
Removed
Modified
  • linux/media

    v9 v10  
    299299Note 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).
    300300
     301Note 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
     302
    301303To 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
    302304
     
    347349[=#v4l2-ctl]
    348350== Capture examples
    349 With the assumption that you have already configured your capture device (see [#media-ctl-setup above) and set it to the {{{DEVICE}}} env variable the following examples are useful examples for capture and streaming:
     351With the assumption that you have already configured your capture device (see [#media-ctl-setup above]) and set it to the {{{DEVICE}}} env variable the following examples are useful examples for capture and streaming:
    350352
    351353Examples:
     
    361363[=#gstreamer]
    362364== GStreamer Capture, Dispaly, and Stream Examples
    363 With the assumption that you have already configured your capture device (see [#media-ctl-setup above) and set it to the {{{DEVICE}}} env variable the following examples are useful examples for capture and streaming:
     365With the assumption that you have already configured your capture device (see [#media-ctl-setup above]) and set it to the {{{DEVICE}}} env variable the following examples are useful examples for capture and streaming:
    364366
    365367