Conclusions

By working directly with v4l2 API the immediate result was a fewer consume of system resources compared to using video capture programs like streamer or ffmpeg.
This system can record video at medium quality and without audio, because the hardware limitations of the Raspberry Pi, so the code needs to be optimize for this computer.
The transmission protocol FTP is extremely fast in the transfer of files over an internal network, if it is needed the transfer of a file from another external network, then the FTP server has to be properly configured.
A better approach of the program algorithm can be obtained by separating the capturing and internet checking processes into two parallel processes, so the video capturing can be more fluid.