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.

/*
 * Implementation of the optional decoder homing feature requires matching
 * the input RTP-encoded GSM-FR frame against the known decoder homing frame.
 * This C module provides this DHF as an API-exported const array.
 */

#include <stdint.h>
#include "tw_gsmfr.h"

const uint8_t gsmfr_decoder_homing_frame[GSMFR_RTP_FRAME_LEN] = {
	0xD2, 0x57, 0x7A, 0x1C, 0xDA,
	0x50, 0x00, 0x49, 0x24, 0x92, 0x49, 0x24,
	0x50, 0x00, 0x49, 0x24, 0x92, 0x49, 0x24,
	0x50, 0x00, 0x49, 0x24, 0x92, 0x49, 0x24,
	0x50, 0x00, 0x49, 0x23, 0x92, 0x49, 0x24,
};