If you by mistake deleted avi files from SD card, or reformat SD card and lost avi videos on the SD card, or other reasons caused avi files to be deleted from SD card, you can recover deleted avi files from sd card with profession data recovery software.
See this one: how to recover data from SD card
The SD card data recovery software is easy to use. You can recover deleted photos, videos, songs, documents, and other files from SD card, microsd, sdhc, sdxc, sd mini, CF card.
You can recover deleted avi files from SanDisk, Kingston, Transcend, Lexar, Panasonic, Toshiba, Sony SD card. The SD card data recovery software works on Windows 10, Windows 8, Windows 7, Windows XP, Windows Vista.
How to undelete files from SD card
How to recover videos from SD card
CF card data recovery