diff --git a/Documentation/admin-guide/media/vivid.rst b/Documentation/admin-guide/media/vivid.rst index 29481241d7cb..1306f19ecb5a 100644 --- a/Documentation/admin-guide/media/vivid.rst +++ b/Documentation/admin-guide/media/vivid.rst @@ -1135,27 +1135,33 @@ Metadata Capture Controls if set, then the generated metadata stream contains Source Clock information. -Video and Sliced VBI Looping ----------------------------- +Video, Sliced VBI and HDMI CEC Looping +-------------------------------------- -The vivid driver supports looping of video output to video input, and VBI -output to VBI input. For video/VBI looping this emulates as if a cable was -hooked up between the output and input connector. So video and VBI looping -is only supported between S-Video and HDMI inputs and outputs. -VBI is only valid for S-Video as it makes no sense for HDMI. +Video Looping functionality is supported for devices created by the same +vivid driver instance, as well as across multiple instances of the vivid driver. +The vivid driver supports looping of video and Sliced VBI data between an S-Video output +and an S-Video input. It also supports looping of video and HDMI CEC data between an +HDMI output and an HDMI input. -Looping is currently supported only between devices created by the same -vivid driver instance. +To enable looping, set the 'HDMI/S-Video XXX-N Is Connected To' control(s) to select +whether an input uses the Test Pattern Generator, or is disconnected, or is connected +to an output. An input can be connected to an output from any vivid instance. +The inputs and outputs are numbered XXX-N where XXX is the vivid instance number +(see module option n_devs). If there is only one vivid instance (the default), then +XXX will be 000. And N is the Nth S-Video/HDMI input or output of that instance. +If vivid is loaded without module options, then you can connect the S-Video 000-0 input +to the S-Video 000-0 output, or the HDMI 000-0 input to the HDMI 000-0 output. +This is the equivalent of connecting or disconnecting a cable between an input and an +output in a physical device. -The way to enable video/VBI looping is currently fairly crude. A 'Loop Video' -control is available in the "Vivid" control class of the video -capture and VBI capture devices. When checked the video looping will be enabled. -Once enabled any video S-Video or HDMI input will show a static test pattern -until the video output has started. At that time the video output will be -looped to the video input provided that: +If an 'HDMI/S-Video XXX-N Is Connected To' control selected an output, then the video +output will be looped to the video input provided that: -- the input type matches the output type. So the HDMI input cannot receive - video from the S-Video output. +- the currently selected input matches the input indicated by the control name. + +- in the vivid instance of the output connector, the currently selected output matches + the output indicated by the control's value. - the video resolution of the video input must match that of the video output. So it is not possible to loop a 50 Hz (720x576) S-Video output to a 60 Hz @@ -1182,6 +1188,8 @@ looped to the video input provided that: "DV Timings Signal Mode" for the HDMI input should be configured so that a valid signal is passed to the video input. +If any condition is not valid, then the 'Noise' test pattern is shown. + The framerates do not have to match, although this might change in the future. By default you will see the OSD text superimposed on top of the looped video. @@ -1344,8 +1352,6 @@ Just as a reminder and in no particular order: - Add ARGB888 overlay support: better testing of the alpha channel - Improve pixel aspect support in the tpg code by passing a real v4l2_fract - Use per-queue locks and/or per-device locks to improve throughput -- Add support to loop from a specific output to a specific input across - vivid instances - The SDR radio should use the same 'frequencies' for stations as the normal radio receiver, and give back noise if the frequency doesn't match up with a station frequency