In any case, they generally fill different niches. FFmpeg is, generally, a library containing set of A/V codecs and (de)muxers. (There are some more obscure parts, too, plus a command line tool ffmpeg(1) that gives access to most aspects of that library.) GStreamer is, generally, an A/V graph framework originally modelled after Microsoft DirectShow.
If you find FFmpeg too difficult to use, most likely what you want isn't a codec library in the first place, but some higher-level abstraction (e.g. if you just want a video on screen, most likely you don't want to muck around with low-level demuxing, but you'd rather want something that deals with clocks and sync and stuff, and FFmpeg just doesn't do that—it's not a video player). It has a lot of weaknesses, but the API is fairly straightforward for what it does.
In any case, they generally fill different niches. FFmpeg is, generally, a library containing set of A/V codecs and (de)muxers. (There are some more obscure parts, too, plus a command line tool ffmpeg(1) that gives access to most aspects of that library.) GStreamer is, generally, an A/V graph framework originally modelled after Microsoft DirectShow.
If you find FFmpeg too difficult to use, most likely what you want isn't a codec library in the first place, but some higher-level abstraction (e.g. if you just want a video on screen, most likely you don't want to muck around with low-level demuxing, but you'd rather want something that deals with clocks and sync and stuff, and FFmpeg just doesn't do that—it's not a video player). It has a lot of weaknesses, but the API is fairly straightforward for what it does.