Media-ctl及拓扑结构

Media-ctl是v4l-utils包中的一个工具，主要用来配置media framework的各节点fmt、size和link。您可通过以下help命令来查询使用方法。

[root@px3se:/]# media-ctl --help
media-ctl [options]
-d, --device dev Media device name (default: /dev/media0)
-e, --entity name Print the device name associated with the given entity
-V, --set-v4l2 v4l2 Comma-separated list of formats to setup
 --get-v4l2 pad Print the active format on a given pad
 --set-dv pad Configure DV timings on a given pad
-h, --help Show verbose help and exit
-i, --interactive Modify links interactively
-l, --links links Comma-separated list of link descriptors to setup
 --known-mbus-fmts List known media bus formats and their numeric values
-p, --print-topology Print the device topology. If an entity
 is specified through the -e option, print
 information for that entity only.
 --print-dot Print the device topology as a dot graph
-r, --reset Reset all links to inactive
-v, --verbose Be verbose
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