android-libetc1 software package provides ETC1 compression library, you can install in your Debian 9 (Stretch) by running the commands given below on the terminal,
$ sudo apt-get update $ sudo apt-get install android-libetc1
android-libetc1 is installed in your system.
Make ensure the android-libetc1 package were installed using the commands given below,
$ sudo dpkg-query -l | grep android-libetc1 *
You will get with android-libetc1 package name, version, architecture and description in a table
| Distro | Debian 9 stretch |
| Section | Libraries |
| Package | android-libetc1 |
| Version | 1:6.0.1+r55-1 |
| Description | ETC1 compression library |
| Sub Section | Libs |