Hello terratec1234,
Thank you for your question.
Unfortunately .flv support is not included in version 3.6.
The list of features and fixes is available on
Video Splitter home page in Version history section. I copy below the list of features of new 3.6 version.
Features:
Saving video frame to JPEG format
Full screen mode
H264 VES saving for MKV, MP4 and ASF formats
Drag and drop input, output files from information panel to other applications
Ability to hide information panel
Saving ADTS AAC for files with AAC audio
Displaying route on the Google, Yandex maps and speedometer, compass, accelerometer readings on DETALECO CamBox CE DVR files
DETALECO CamBox CE DVR files trimming and joining with saving GPS extra data