For example: https://github.com/CCExtractor/ccextractor/blob/b488126d09de590268a49d6bb18f6c8285147cbf/src/lib_ccx/ccx_encoders_smptett.c#L221
sprintf()
is configured by LC_NUMERIC. See: https://linux.die.net/man/3/sprintf Format of the format string
Final output is inconsistent and it is hard to parse. Do you consider some better solution?