etc1 require minum openGL version

It's an extension for OpenGL ES 2.0, so it's not mandatory on any implementation. You'll need to check the extension strings on the platform you are running on to see if this is supported.

http://www.khronos.org/registry/gles/extensions/OES/OES_compressed_ETC1_RGB8_texture.txt

ETC2 (which is a superset of ETC1) is mandatory in OpenGL ES 3.0 onwards.

HTH,
Pete

It's an extension for OpenGL ES 2.0, so it's not mandatory on any implementation. You'll need to check the extension strings on the platform you are running on to see if this is supported.

http://www.khronos.org/registry/gles/extensions/OES/OES_compressed_ETC1_RGB8_texture.txt

ETC2 (which is a superset of ETC1) is mandatory in OpenGL ES 3.0 onwards.

HTH,
Pete