FreeCalypso > hg > gsm-codec-lib
view libtwamr/dec_lag3.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 | fb001496ca8c |
| 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 : dec_lag3.h * Purpose : Decoding of fractional pitch lag with 1/3 resolution. * Extract the integer and fraction parts of the pitch lag from * the received adaptive codebook index. * ******************************************************************************** */ #ifndef dec_lag3_h #define dec_lag3_h "$Id $" /* ******************************************************************************** * INCLUDE FILES ******************************************************************************** */ #include "typedef.h" /* ******************************************************************************** * LOCAL VARIABLES AND TABLES ******************************************************************************** */ /* ******************************************************************************** * DEFINITION OF DATA TYPES ******************************************************************************** */ /* ******************************************************************************** * DECLARATION OF PROTOTYPES ******************************************************************************** */ /************************************************************************* * FUNCTION: Dec_lag3 * * PURPOSE: Decoding of fractional pitch lag with 1/3 resolution. * Extract the integer and fraction parts of the pitch lag from * the received adaptive codebook index. * * See "Enc_lag3.c" for more details about the encoding procedure. * * The fractional lag in 1st and 3rd subframes is encoded with 8 bits * while that in 2nd and 4th subframes is relatively encoded with 4, 5 * and 6 bits depending on the mode. * *************************************************************************/ void Dec_lag3(Word16 index, /* i : received pitch index */ Word16 T0_min, /* i : minimum of search range */ Word16 T0_max, /* i : maximum of search range */ Word16 i_subfr, /* i : subframe flag */ Word16 T0_prev, /* i : integer pitch delay of last subframe used in 2nd and 4th subframes */ Word16 * T0, /* o : integer part of pitch lag */ Word16 * T0_frac, /* o : fractional part of pitch lag */ Word16 flag4 /* i : flag for encoding with 4 bits */ ); #endif