[FFmpeg-user] How to change overlay parameter at runtime

Ted Park kumowoon1025 at gmail.com
Fri Mar 27 15:36:29 EET 2020


> realtime filter is irrelevant here since you're using -re.  sendcmd parses its argument once at init, so can't be used to add or change arguments.

But wouldn’t it make a difference if zmq was being used to send commands? Or do you mean because it's reading at realtime? I think you could set up a filterchain that reads input at realtime but outputs (and encode/render/write) frames with polynomial PTS.

What I’ve always wanted to add to the examples section is a sort of libavfilter/libavformat REPL using zmq, with the filtergraph dot graph visualized in the terminal, and maybe some real time monitoring capability, though that might need to automatically render fractionally (which I’m lost on) in some situations, viz fps drops on sending command.

Not that I have any of the hard part of this done yet, but recently I noticed rabbitmq support in the configure script, in addition to zmq. I’ve never heard of rabbitmq, can someone comment on the differences between them? Is it more popular? It’d be hard to be easier or lighter than 0mq but if anyone is familiar with it I’d be much obliged.

Ted Park

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