we are working on an integration with our mobile application where we are trying to create a live feed backend API that connects to an RTSP URL and returns some video data.

The process we thought about is the following:
mobile application -> /api/realtime/camera -> starts an FFMPEG process that connects to an RTSP url -> write process' input stream to API's response using webflux.

This is a code snippet:

----------- process init -----------------------------
        ProcessBuilder ffmpegBuilder = new ProcessBuilder(
                "ffmpeg",
                "-rtsp_transport", "tcp",
                "-i", rtspConnection,
                "-c:v", "libx264",
                "-preset", "ultrafast",
                "-tune", "zerolatency",
                "-b:v", "2000k",
                "-an",
                "-f", "mp4",
                "-movflags", "frag_keyframe+empty_moov+default_base_moof",
                "pipe:1");
        

------------- process read & push to spring reactive Sink ------------------
        try (var inputStream = ffmpegProcess.getInputStream()) {
            byte[] buffer = new byte[8192];
            int bytesRead;

            while ((bytesRead = inputStream.read(buffer)) != -1) {
                DataBuffer dataBuffer = new DefaultDataBufferFactory().wrap(copyOf(buffer, bytesRead));
                sink.emitNext(dataBuffer, Sinks.EmitFailureHandler.FAIL_FAST);
            }
        } catch (Exception e) {
            sink.emitError(e, Sinks.EmitFailureHandler.FAIL_FAST);
        } finally {
            this.dispose();
        }


----------------- API that will eventually transform previous sink as flux -----------
    @GetMapping(value = "/{deviceId}/camera", produces = "video/mp4")
    public Flux streamCamera(@PathVariable Long deviceId) {
        // return previous sink as flux
    }

The problem is that we realized that in a web context, in case that multiple users will open a connection to this API, this will eventually start a lot of background processes and it might cause OOM or other issues with our machine.

Questions:

• is this the way to go for such feature? or should the mobile app connect directly to the RTSP url?

• are there any ffmpeg-friendly libraries for java?