Why wouldn't you? RTMP is one of the most common ways to stream video and if you're already receiving live audio/video data from a tuner then you can easily pac

Why wouldn't you? RTMP is one of the most common ways to stream video and if you're already receiving live audio/video data from a tuner then you can easily package it into an RTMP stream going out to any number of archive servers running ffmpeg (which does the hard work of any transcoding or remuxing you need to do). All you have to do is package the RTMP stream, build ffmpeg yourself with nonfree and gpl options enabled, and run/monitor off-the-shelf software with an obnoxious number of command line arguments. Chances are you can package the RTMP stream straight from the source using ffmpeg too. I don't know about the SDR vs tuner question but many SDRs are made with TV tuners and I'd bet you'd have more luck (especially long term) with the software written by the amateur radio community than whatever company makes your brand of TV tuner.