Seek to a desired MPEG frame offset.
* Usage is modelled afer the standard lseek().
* \param mh handle
* \param frameoff offset in MPEG frames
* \param whence one of SEEK_SET, SEEK_CUR or SEEK_END
* \return The resulting offset >= 0 or error/message code
Seek to a desired MPEG frame offset. * Usage is modelled afer the standard lseek(). * \param mh handle * \param frameoff offset in MPEG frames * \param whence one of SEEK_SET, SEEK_CUR or SEEK_END * \return The resulting offset >= 0 or error/message code