FreeCalypso > hg > gsm-codec-lib

annotate libtwamr/dhf_subst2.c @ 605:63f774192906

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
gsmhr_decoder_twts002_in(): set BFI=1 SID=1 for invalid SID When a received TW-TS-002 RTP payload indicates invalid SID, which of the 3 possible BFI/SID combinations should we pass to our internal ETSI-based speech decoder or TFO engine? Our original code passed BFI=0 SID=1, but upon further reflection, BFI=1 SID=1 is a better choice. In the corner case where received invalid SID is fed to a full decoder in homed state, setting BFI=1 allows that decoder to emit zeros on PCM and stay homed, instead of launching into full decoding.
author Mychaela Falconia <falcon@freecalypso.org>
date Thu, 04 Dec 2025 21:01:46 +0000
parents fa0652115168
children
Ignore whitespace changes - Everywhere: Within whitespace: At end of lines:
rev   line source
464
fa0652115168 libtwamr: add amr_dhf_subst_efr2()
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1 /*
fa0652115168 libtwamr: add amr_dhf_subst_efr2()
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
2 * The function implemented in this module is an aid for AMR-EFR interworking;
fa0652115168 libtwamr: add amr_dhf_subst_efr2()
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
3 * it is meant to be invoked directly after amr_encode_frame(). It checks
fa0652115168 libtwamr: add amr_dhf_subst_efr2()
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
4 * the encoder output for MR122 DHF and turns it into EFR DHF just like
fa0652115168 libtwamr: add amr_dhf_subst_efr2()
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
5 * amr_dhf_subst_efr(), but only if the input PCM frame was an EHF. This
fa0652115168 libtwamr: add amr_dhf_subst_efr2()
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
6 * slightly more complicated logic is needed in order to replicate the observed
fa0652115168 libtwamr: add amr_dhf_subst_efr2()
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
7 * behavior of AMR-EFR speech encoder in the extant GSM network of T-Mobile USA.
fa0652115168 libtwamr: add amr_dhf_subst_efr2()
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
8 */
fa0652115168 libtwamr: add amr_dhf_subst_efr2()
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
9
fa0652115168 libtwamr: add amr_dhf_subst_efr2()
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
10 #include "tw_amr.h"
fa0652115168 libtwamr: add amr_dhf_subst_efr2()
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
11 #include "namespace.h"
fa0652115168 libtwamr: add amr_dhf_subst_efr2()
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
12 #include "e_homing.h"
fa0652115168 libtwamr: add amr_dhf_subst_efr2()
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
13
fa0652115168 libtwamr: add amr_dhf_subst_efr2()
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
14 void amr_dhf_subst_efr2(struct amr_param_frame *frame, const int16_t *pcm)
fa0652115168 libtwamr: add amr_dhf_subst_efr2()
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
15 {
fa0652115168 libtwamr: add amr_dhf_subst_efr2()
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
16 if (encoder_homing_frame_test(pcm))
fa0652115168 libtwamr: add amr_dhf_subst_efr2()
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
17 amr_dhf_subst_efr(frame);
fa0652115168 libtwamr: add amr_dhf_subst_efr2()
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
18 }