When calling freedv_get_bits_per_modem_frame//8 for all the data modes I get the raw byte count for the modem (including the crc length). Eg for DATAC3 I get 128 while in the documentation says 126 - which is what I expect.

For DATAC1 however the documentation says 56 bytes and the call returns back 56, suggesting that the documentation should probably have 54 in it rather than 56 ?