Should Translations of some GPL code to other languages be licensed as GPL?
For ex we have x264 C/C++ H264 encoding open source GPL lib. We translate it from… C\C++ to Java or C# should we license our code as GPL?
Yes, GPL code translated to another language or platform is still subject to the terms of the GPL. It constitutes a "modified version."
IANAL, but, yes it would count as a derivative work
The GPL stipulates that all derivative works share its license.
I guess that legally you may not be obliged to license under the GPL depending on how you port the software, but you certainly should license under the GPL as the original author's intention is obviously to apply the GPL to all other software based off of the GPL'd work.
来源：https://stackoverflow.com/questions/1723606/should-translations-of-some-gpl-code-to-other-languages-be-licensed-as-gpl