If you are not an FFmpeg expert, use other video editing software. If you are an FFmpeg expert, you don’t need to use ffmpeg at all (but perhaps consider helping to improve this code!). Ultimately, if you want an incredibly fancy video, do not rely on ffmpeg to splice and merge and overlay and juxtapose all your layers together, to crop and pan and rotate, to apply effects and transitions and every other form of video processing to your image sequences finish the production outside of R, because that is what makes sense. ffmpeg is provided in mapmate as an exception to the rule for users who wish to trade the full control and flexibility over video editing and production that mapmate aims to avoid entangling itself with for the convenience of generating relatively basic video output directly from an R session. Any animation is expected to be done later by the user via software dedicated to video editing and production. The goal that mapmate attempts to fulfill is strictly that of animation pre-production and it does so by focusing on the generation of still image sequences.

See packages like animation if that is the goal. Keep in mind that the purpose of mapmate is not to generate animations directly from R. While additional uses may be incorporated into ffmpeg in future, the FFmpeg multimedia framework itself provides a far broader suite of tools and functionality than currently is needed here. Since this function is provided in the context of the mapmate package, it is aimed at assisting with converting still image sequences to video. The ffmpeg R function is primarily useful to users not well versed in the use of the FFmpeg multimedia framework who will be satisfied with the level of flexibility provided. Ffmpeg does not provide complete flexibility to allow making every possible valid call to FFmpeg, but users who are that well versed in the use of FFmpeg can use the command line utility directly or pass their custom calls directly to system from within R.

Ffmpeg map image