annotate libtwamr/dhf_subst2.c @ 485:751f06541fbb

doc/Codec-utils: clarify lack of DHF in gsmfr-decode-rb
author Mychaela Falconia <falcon@freecalypso.org>
date Mon, 20 May 2024 01:47:22 +0000
parents fa0652115168
children
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fa0652115168 libtwamr: add amr_dhf_subst_efr2()
Mychaela Falconia <falcon@freecalypso.org>
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1 /*
fa0652115168 libtwamr: add amr_dhf_subst_efr2()
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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>
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3 * it is meant to be invoked directly after amr_encode_frame(). It checks
fa0652115168 libtwamr: add amr_dhf_subst_efr2()
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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>
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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>
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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>
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7 * behavior of AMR-EFR speech encoder in the extant GSM network of T-Mobile USA.
fa0652115168 libtwamr: add amr_dhf_subst_efr2()
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8 */
fa0652115168 libtwamr: add amr_dhf_subst_efr2()
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9
fa0652115168 libtwamr: add amr_dhf_subst_efr2()
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10 #include "tw_amr.h"
fa0652115168 libtwamr: add amr_dhf_subst_efr2()
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11 #include "namespace.h"
fa0652115168 libtwamr: add amr_dhf_subst_efr2()
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12 #include "e_homing.h"
fa0652115168 libtwamr: add amr_dhf_subst_efr2()
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13
fa0652115168 libtwamr: add amr_dhf_subst_efr2()
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14 void amr_dhf_subst_efr2(struct amr_param_frame *frame, const int16_t *pcm)
fa0652115168 libtwamr: add amr_dhf_subst_efr2()
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15 {
fa0652115168 libtwamr: add amr_dhf_subst_efr2()
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16 if (encoder_homing_frame_test(pcm))
fa0652115168 libtwamr: add amr_dhf_subst_efr2()
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17 amr_dhf_subst_efr(frame);
fa0652115168 libtwamr: add amr_dhf_subst_efr2()
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18 }