view frtest/decode.c @ 183:452c1d5a6268

libgsmefr BFI w/o data: emit zero output after decoder reset In real-life usage, each EFR decoder session will most likely begin with lots of BFI frames before the first real frame arrives. However, because the spec-defined home state of the decoder is speech rather than CN, our regular logic for BFI w/o data would have to feed pseudorandom noise to the decoder (in the "fixed codebook excitation pulses" part), which is silly to do at the beginning of the decoder session right out of reset. Therefore, let's check reset_flag_old, and if we are still in the reset state, simply emit zero output.
author Mychaela Falconia <falcon@freecalypso.org>
date Tue, 03 Jan 2023 00:12:18 +0000
parents b9a842775f40
children 8d3cfa65a6c2
line wrap: on
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/*
 * This file is the main module for gsmfr-decode utility.
 */

#include <stdio.h>
#include <stdint.h>
#include <stdlib.h>
#include <gsm.h>
#include "../libgsmfrp/gsm_fr_preproc.h"
#include "../libtest/binreader.h"
#include "../libtest/wavwriter.h"
#include "../libtest/pcmwrite.h"

main(argc, argv)
	char **argv;
{
	FILE *binf;
	void *wav;
	gsm dec_state;
	struct gsmfr_preproc_state *pp_state;
	uint8_t frame[BINFILE_MAX_FRAME];
	int16_t pcm[160];
	int rc, bfi, taf;

	if (argc != 3) {
		fprintf(stderr, "usage: %s input.gsm output.wav\n", argv[0]);
		exit(1);
	}
	binf = fopen(argv[1], "r");
	if (!binf) {
		perror(argv[1]);
		exit(1);
	}
	wav = wav_write_open(argv[2], 8000, 16, 1);
	if (!wav) {
		perror(argv[2]);
		exit(1);
	}
	dec_state = gsm_create();
	if (!dec_state) {
		fprintf(stderr, "gsm_create() failed!\n");
		exit(1);
	}
	pp_state = gsmfr_preproc_create();
	if (!pp_state) {
		fprintf(stderr, "gsmfr_preproc_create() failed!\n");
		exit(1);
	}
	for (;;) {
		rc = binfile_read_frame(binf, frame);
		if (rc < 0) {
			fprintf(stderr, "error: garbage in %s\n", argv[1]);
			exit(1);
		}
		if (!rc)
			break;
		if (frame[0] == 0xBF) {
			bfi = 1;
			taf = frame[1] & 1;
		} else if ((frame[0] & 0xF0) == 0xD0)
			bfi = 0;
		else {
			fprintf(stderr, "error: %s is not in FR codec format\n",
				argv[1]);
			exit(1);
		}
		if (bfi)
			gsmfr_preproc_bfi(pp_state, taf, frame);
		else
			gsmfr_preproc_good_frame(pp_state, frame);
		gsm_decode(dec_state, frame, pcm);
		write_pcm_to_wav(wav, pcm);
	}
	wav_write_close(wav);
	exit(0);
}