FreeCalypso > hg > gsm-codec-lib
view libtwamr/lpc.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 | 9adfe3863a41 |
| children |
line wrap: on
line source
/* ******************************************************************************** * * 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 : lpc.h * Purpose : 2 LP analyses centered at 2nd and 4th subframe * for mode 12.2. For all other modes a * LP analysis centered at 4th subframe is * performed. * ******************************************************************************** */ #ifndef lpc_h #define lpc_h "$Id $" /* ******************************************************************************** * INCLUDE FILES ******************************************************************************** */ #include "tw_amr.h" #include "typedef.h" #include "levinson.h" /* ******************************************************************************** * LOCAL VARIABLES AND TABLES ******************************************************************************** */ /* ******************************************************************************** * DEFINITION OF DATA TYPES ******************************************************************************** */ typedef struct { LevinsonState levinsonSt; } lpcState; /* ******************************************************************************** * DECLARATION OF PROTOTYPES ******************************************************************************** */ void lpc_reset (lpcState *st); /* reset of pre processing state (i.e. set state memory to zero) returns 0 on success */ int lpc( lpcState *st, /* i/o: State struct */ enum Mode mode, /* i : coder mode */ Word16 x[], /* i : Input signal Q15 */ Word16 x_12k2[], /* i : Input signal (EFR) Q15 */ Word16 a[] /* o : predictor coefficients Q12 */ ); #endif