FreeCalypso > hg > gsm-codec-lib
view efrtest/decode-tw5.c @ 605:63f774192906
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 | f9535c1fbf70 |
| children |
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/* * This file is the main module for gsmefr-decode-tw5 utility. It is just * like the original gsmefr-decode, but reads the GSM-EFR speech recording * from TW-TS-005 Annex A hexadecimal format instead of the old gsmx * binary format. */ #include <stdio.h> #include <stdint.h> #include <stdlib.h> #include "../libgsmefr/gsm_efr.h" #include "../libtest/tw5reader.h" #include "../libtest/wavwriter.h" #include "../libtest/pcmwrite.h" main(argc, argv) char **argv; { FILE *hexf; void *wav; unsigned lineno; struct EFR_decoder_state *state; uint8_t frame[TWTS005_MAX_FRAME]; unsigned frame_len; int16_t pcm[160]; int rc; if (argc != 3) { fprintf(stderr, "usage: %s input.hex output.wav\n", argv[0]); exit(1); } hexf = fopen(argv[1], "r"); if (!hexf) { perror(argv[1]); exit(1); } lineno = 0; wav = wav_write_open(argv[2], 8000, 16, 1); if (!wav) { perror(argv[2]); exit(1); } state = EFR_decoder_create(); if (!state) { perror("EFR_decoder_create()"); exit(1); } for (;;) { rc = twts005_read_frame(hexf, &lineno, frame, &frame_len); if (rc < 0) { fprintf(stderr, "%s line %u: not valid TW-TS-005\n", argv[1], lineno); exit(1); } if (!rc) break; rc = EFR_decode_rtp(state, frame, frame_len, pcm); if (rc < 0) { fprintf(stderr, "%s line %u: not a valid GSM-EFR frame\n", argv[1], lineno); exit(1); } write_pcm_to_wav(wav, pcm); } wav_write_close(wav); exit(0); }
