Converting .3gp files to .bik format.
Converting 3GPP Multimedia Files directly to Bink Video Files (.3gp to .bik conversion) should be possible and quite straightforward, even though your options might be limited.
You can use the Freemake Video Converter, which should be perfectly capable of converting .3gp to .bik.
One of the most popular and successful free video conversion softwares
A free software for MP4/3GP file conversions of portable video devices.