How to merge video and audio streams in Linux without GUI?

Question

linux

Good afternoon.
Never worked with video streams before. I have been digging into the aplay and arecord utilities for a long time to reconfigure them to work with a specific audio codec.
But there was a simple recording and playback of files.
At the moment, there is a task to create a video camera based on one of the Texas Instruments processors. The TI processor was not chosen by chance, because. implies the presence of a serious periphery.
Also, chips that are more suitable for this business (for example, from Ambarella) are not suitable, because. The camera will be analog.
Most camera and recorder firmwares are made without using Linux. This situation does not suit me, again because of the presence of the periphery.
One of the few cameras running on the OS is the well-known GoPro (at least before). But the RTOS system is used there, and, of course, there are no source codes anywhere.
Hence, there is a need to find software for Linux, which, with minimal changes, will be able to receive video and audio streams, glue them on the fly, convert them to a specific codec, and burn them to disk.
There are no problems with sound, the already well-known aplay will help here, you just have to intercept the audio stream before writing to disk.
With the video stream, I was hoping for help from the ffmpeg utility, but all the manuals show its work with existing files. Whether it can work with a video stream, I still do not understand.
Can you please tell me which utilities, in your opinion, will more correctly cope with the above task?
It will also be interesting to hear any opinions on this matter, perhaps due to inexperience in this area, I globally do not approach the issue correctly.

Answer 1

I recommend taking a serious look at gstreamer, especially since TI has codecs for it, as well as v4l video. About aplay - forget it, it's not from this opera, you need to not only record audio, but also synchronize it with video, and put it into the right container to the heap.
As for ffmpeg, yes, it can also from a stream and from a file and back and forth, but somehow it so happened that they still use gstreamer, especially on embedded.
processors.wiki.ti.com/index.php/GStreamer
http://wiki.virt2real.ru/w/GStreamer_and_its_chains

Answer 2

https://www.wowza.com/forums/showthread.php?31609-...
https://ubuntuforums.org/showthread.php?t=2294696
tk "all file" no difference what file is actually