FreeCalypso > hg > gsm-codec-lib
view libgsmefr/dec_main.c @ 282:9ee8ad3d4d30
frtest: rm gsmfr-hand-test and gsmfr-max-out utils
These hack programs were never properly documented and were written
only as part of a debug chase, in pursuit of a bug that ultimately
turned out to be in our then-hacky patch to osmo-bts-sysmo,
before beginning of proper patches in Osmocom. These hack programs
need to be dropped from the present sw package because they depend
on old libgsm, and we are eliminating that dependency.
author | Mychaela Falconia <falcon@freecalypso.org> |
---|---|
date | Sun, 14 Apr 2024 05:44:47 +0000 |
parents | 18866c0354ef |
children |
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/* * This module contains our GSM EFR decoder main function, EFR_decode_params(), * that stands at the boundary between our public interface and the guts of * ETSI-based codec. */ #include "gsm_efr.h" #include "typedef.h" #include "namespace.h" #include "basic_op.h" #include "cnst.h" #include "codec.h" #include "sig_proc.h" #include "memops.h" #include "dec_state.h" #include "d_homing.h" /* These constants define the number of consecutive parameters that function decoder_homing_frame_test() checks */ #define WHOLE_FRAME 57 #define TO_FIRST_SUBFRAME 18 void EFR_decode_params(struct EFR_decoder_state *st, const int16_t *params, int bfi, int SID_flag, int TAF, int16_t *pcm_out) { Word16 *synth = st->synth_buf + M; Word16 Az_dec[AZ_SIZE]; Word16 i, temp; Word16 reset_flag; if (!bfi) /* BFI == 0, perform DHF check */ { if (st->reset_flag_old) /* Check for second and further successive DHF (to first subfr.) */ { reset_flag = decoder_homing_frame_test (params, TO_FIRST_SUBFRAME); } else { reset_flag = 0; } } else /* BFI==1, bypass DHF check (frame is taken as not being a DHF) */ { reset_flag = 0; } if (reset_flag && st->reset_flag_old) { /* Force the output to be the encoder homing frame pattern */ for (i = 0; i < L_FRAME; i++) { synth[i] = EHF_MASK; } } else { /* Synthesis */ Decoder_12k2 (st, bfi, params, synth, Az_dec, TAF, SID_flag); Post_Filter (st, synth, Az_dec); /* Post-filter */ for (i = 0; i < L_FRAME; i++) /* Upscale the 15 bit linear PCM to 16 bits, then truncate to 13 bits */ { temp = shl (synth[i], 1); synth[i] = temp & 0xfff8; } } /* else */ Copy (synth, pcm_out, L_FRAME); /* BFI == 0, perform check for first DHF (whole frame) */ if (!bfi && !st->reset_flag_old) { reset_flag = decoder_homing_frame_test (params, WHOLE_FRAME); } if (reset_flag) { /* Bring the decoder and receive DTX to the home state */ EFR_decoder_reset(st); } else { st->reset_flag_old = 0; } }