| libplatform Notes |
| ***************** |
| |
| libplatform is a private library used by this project for portability |
| across platforms. Simple file access, getting system time, parsing |
| command-line arguments, endian byte-swap macros, are examples of |
| things that belong in this convenience library. |
| |
| The implementation means to support the following platforms: |
| |
| - posix (the default) |
| - win32 (Windows 2000 or newer) |
| |
| |
| All symbols in libplatform reside in private namespace mp4v2::platform |
| and must never be made visible through public interfaces. In general, |
| implementation .h and .cpp files are free to include this library. |
| |
| Both libmp4v2 and various executables created by this project rely on |
| libplatform and this creates a bit of a dilemma in that libmp4v2 must |
| ship as a stand-alone library. Thus, when creating libmp4v2 we must always |
| embed the needed bits from libplatform. In turn, the executables then |
| link against both libmp4v2 and the remaining bits of libplatform. |
| |
| This approach requires advanced linking which is available using |
| several different methods, varying by platforms. And to complicate |
| matters further, libtool (even version 2.2.6) makes this impossible. |
| So the simple solution is to add libplatform symbols to libmp4v2. |
| The only problem with this is libmp4v2 becomes a little fatter than |
| it needs to be, but since all the symbols are in a private namespace |
| and we use set default symbol visibility to hidden, we protect our |
| clients from inadvertantly becoming dependents. |
| |
| If libplatform ever becomes bulky we can revisit this issue, but at |
| this time using advanced linking would only save ~10KB of binary size. |
