libtwamr encoder: always emit frame->mode = mode; In the original implementation of amr_encode_frame(), the 'mode' member of the output struct was set to 0xFF if the output frame type is TX_NO_DATA. This design was made to mimic the mode field (16-bit word) being set to 0xFFFF (or -1) in 3GPP test sequence format - but nothing actually depends on this struct member being set in any way, and amr_frame_to_tseq() generates the needed 0xFFFF on its own, based on frame->type being equal to TX_NO_DATA. It is simpler and more efficient to always set frame->mode to the actual encoding mode in amr_encode_frame(), and this new behavior has already been documented in doc/AMR-library-API description in anticipation of the present change.

/* Double precision operations */

void L_Extract (Word32 L_32, Word16 *hi, Word16 *lo);
Word32 L_Comp (Word16 hi, Word16 lo);
Word32 Mpy_32 (Word16 hi1, Word16 lo1, Word16 hi2, Word16 lo2);
Word32 Mpy_32_16 (Word16 hi, Word16 lo, Word16 n);
Word32 Div_32 (Word32 L_num, Word16 denom_hi, Word16 denom_lo);