FreeCalypso > hg > gsm-codec-lib
view libtwamr/autocorr.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 | 54f6bc41ed10 |
| 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 : autocorr.h * Purpose : Compute autocorrelations of signal with windowing * ******************************************************************************** */ #ifndef autocorr_h #define autocorr_h "$Id $" /* ******************************************************************************** * INCLUDE FILES ******************************************************************************** */ #include "typedef.h" /* ******************************************************************************** * DEFINITION OF DATA TYPES ******************************************************************************** */ /* ******************************************************************************** * DECLARATION OF PROTOTYPES ******************************************************************************** */ /* ************************************************************************** * * Function : autocorr * Purpose : Compute autocorrelations of signal with windowing * Description : - Windowing of input speech: s'[n] = s[n] * w[n] * - Autocorrelations of input speech: * r[k] = sum_{i=k}^{239} s'[i]*s'[i-k] k=0,...,10 * The autocorrelations are expressed in normalized * double precision format. * Returns : Autocorrelation * ************************************************************************** */ Word16 Autocorr ( Word16 x[], /* (i) : Input signal (L_WINDOW) */ Word16 m, /* (i) : LPC order */ Word16 r_h[], /* (o) : Autocorrelations (msb) (MP1) */ Word16 r_l[], /* (o) : Autocorrelations (lsb) (MP1) */ const Word16 wind[]/* (i) : window for LPC analysis. (L_WINDOW) */ ); #endif