uvgRTP doesn't compile on CentOS7

[lhp-git]

I am using uvgRTP for a streaming application developped on CentOS7.9. Upgrading the OS is not an option.
Until now, I used the 1.0.0 release. I had to modify the random.cc file (more on this later) but the build succedeed.
I now want to upgrade to the 2.0.0 release. Unfortunately, the Makefile generated by cmake3 hardcodes the C++ standard version to c++17. The gcc compiler of CentOS7.9 is 4.8.5, which supports only c++11.

Wouldn't it be possible to ensure uvgrtp compiles with c++11 ?

The only thing that is specific to c++17 is located in the include/crypto.hh file.

I suggest to replace :
#if __has_include(<cryptopp/aes.h>) &&
...
!defined(RTP_NO_CRYPTO)

#define RTP_CRYPTO

#include <cryptopp/aes.h>
...
#endif

with :
#ifndef RTP_NO_CRYPTO
#include <cryptopp/aes.h>
...
#endif

The second point that is not available on CentOS7 is the getrandom() function.
I suggest to use the SYS_getrandom system call if the getrandom() function isn't available (HAVE_GETRANDOM undefined).
I have attached the modified file random.cc
random.txt

[altonen]

Hi,

unfortunately it was decided that for the sake of user experience, Crypto++ should be checked and enabled automatically. There was internal debate about this but this was the direction that was chosen for uvgRTP and thus, unfortunately for you, I don't see this change being merged to master. On the other hand, I'm no longer in a position to make any decisions regarding uvgRTP (that's now Joni's or Marko's job) so you may also try your luck and open a pull request for the Crypto++ detection update and see what happens.

The updates regarding crypto.cc look good to me and if you want them to be merged to master, please open a pull request.

[lhp-git]

Thank you for your quick answer.

I will guard my modifications to the crypto.hh file with a check to the GCC version (< 5), hence the "official" Crypto++ remains unchanged if GCC version is > 5. I will try my luck with a pull request for this, and another for the getrandom() function.

What about the hardcoding of the standard c++17 in the CMakeLists.txt ? This requirement isn't mentioned in the BUILDING.md, and is new with the 2.0.0 version. This is disapointing for users of the 1.0.0 who wants to upgrade.

[altonen]

Checking against GCC's version sounds reasonable to me. As you mentioned, uvgRTP only uses the __has_include from C++17 so you could modify the CMake file to detect if a C++17-compatible compiler is present and enable -std=c++17 if so. And if not, it could default to C++11 and use your GCC version check code to enable/disable crypto (if merged to master).

[lhp-git]

I will prepare a pull request, but for that I need to learn how to do it. I think there are tutorials for that.

[lhp-git]

PR "build: Support for CentOS7 #18" submitted

[lhp-git]

The PR #18 has been merged. I can close this issue now.