view amrtest/decode.c @ 478:936a08cc73ce

doc/AMR-library-API: describe the decoder
author Mychaela Falconia <falcon@freecalypso.org>
date Sun, 19 May 2024 21:32:31 +0000
parents fe4983b05230
children
line wrap: on
line source

/*
 * twamr-decode is a speech decoder utility going from *.amr input
 * to WAV output.  It logically replaces amrnb-dec from opencore-amr
 * package.
 */

#include <stdio.h>
#include <stdint.h>
#include <stdlib.h>
#include <string.h>
#include <strings.h>
#include "../libtwamr/tw_amr.h"
#include "../libtest/wavwriter.h"
#include "../libtest/pcmwrite.h"

main(argc, argv)
	char **argv;
{
	FILE *inf;
	void *wav;
	uint8_t frm_in[AMR_IETF_MAX_PL];
	struct amr_decoder_state *state;
	struct amr_param_frame frame;
	int16_t pcm[160];
	int rc;

	if (argc != 3) {
		fprintf(stderr, "usage: %s input.amr output.wav\n", argv[0]);
		exit(1);
	}
	inf = fopen(argv[1], "r");
	if (!inf) {
		perror(argv[1]);
		exit(1);
	}
	if (fread(frm_in, 1, AMR_IETF_HDR_LEN, inf) != AMR_IETF_HDR_LEN ||
	    bcmp(frm_in, amr_file_header_magic, AMR_IETF_HDR_LEN)) {
		fprintf(stderr, "error: %s is not in IETF AMR format\n",
			argv[1]);
		exit(1);
	}
	wav = wav_write_open(argv[2], 8000, 16, 1);
	if (!wav) {
		perror(argv[2]);
		exit(1);
	}
	state = amr_decoder_create();
	if (!state) {
		perror("amr_decoder_create()");
		exit(1);
	}
	for (;;) {
		rc = getc(inf);
		if (rc < 0)
			break;
		frm_in[0] = rc;
		rc = amr_ietf_grok_first_octet(frm_in[0]);
		if (rc < 0) {
inv:			fprintf(stderr, "error: %s contains invalid AMR data\n",
				argv[1]);
			exit(1);
		}
		if (rc && fread(frm_in+1, 1, rc, inf) != rc)
			goto inv;
		amr_frame_from_ietf(frm_in, &frame);
		amr_decode_frame(state, &frame, pcm);
		write_pcm_to_wav(wav, pcm);
	}
	wav_write_close(wav);
	exit(0);
}