FreeCalypso > hg > gsm-codec-lib
view libtwamr/bgnscd.h @ 477:4c9222d95647
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.
| author | Mychaela Falconia <falcon@freecalypso.org> |
|---|---|
| date | Sat, 18 May 2024 22:30:42 +0000 |
| parents | 8dfb7cbe6b59 |
| children |
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/* ******************************************************************************** * * GSM AMR-NB speech codec R98 Version 7.6.0 December 12, 2001 * R99 Version 3.3.0 * REL-4 Version 4.1.0 * ******************************************************************************** * * File : bgnscd.h * Purpose : Background noise source charateristic detector (SCD) * ******************************************************************************** */ #ifndef bgnscd_h #define bgnscd_h "$Id $" /* ******************************************************************************** * INCLUDE FILES ******************************************************************************** */ #include "typedef.h" #include "cnst.h" /* ******************************************************************************** * LOCAL VARIABLES AND TABLES ******************************************************************************** */ #define L_ENERGYHIST 60 #define INV_L_FRAME 102 /* 2*(160*x)^2 / 65536 where x is FLP values 150,5 and 50 */ #define FRAMEENERGYLIMIT 17578 /* 150 */ #define LOWERNOISELIMIT 20 /* 5 */ #define UPPERNOISELIMIT 1953 /* 50 */ /* ******************************************************************************** * DEFINITION OF DATA TYPES ******************************************************************************** */ typedef struct{ /* history vector of past synthesis speech energy */ Word16 frameEnergyHist[L_ENERGYHIST]; /* state flags */ Word16 bgHangover; /* counter; number of frames after last speech frame */ } Bgn_scdState; /* ******************************************************************************** * DECLARATION OF PROTOTYPES ******************************************************************************** */ /* ************************************************************************** * * Function : Bgn_scd_reset * Purpose : Resets state memory * Returns : 0 on success * ************************************************************************** */ void Bgn_scd_reset (Bgn_scdState *st); /* ************************************************************************** * * Function : Bgn_scd * Purpose : Charaterice synthesis speech and detect background noise * Returns : background noise decision; 0 = bgn, 1 = no bgn * ************************************************************************** */ Word16 Bgn_scd (Bgn_scdState *st, /* i : State variables for bgn SCD */ Word16 ltpGainHist[], /* i : LTP gain history */ Word16 speech[], /* o : synthesis speech frame */ Word16 *voicedHangover /* o : # of frames after last voiced frame */ ); #endif