trx/tx.c

236 lines
4.6 KiB
C

#include <netdb.h>
#include <string.h>
#include <alsa/asoundlib.h>
#include <celt/celt.h>
#include <sys/socket.h>
#include <sys/types.h>
#include "defaults.h"
#include "device.h"
#include "sched.h"
#define ENCODED_BYTES 128
typedef int seq_t;
/*
* Bind to network socket, for sending to the given host and port
*/
static int bind_to_network(const char *host, const char *service,
struct addrinfo **servinfo, struct addrinfo **theirs)
{
int r, sd;
struct addrinfo hints, *p;
memset(&hints, 0, sizeof(hints));
hints.ai_family = AF_UNSPEC;
hints.ai_socktype = SOCK_DGRAM;
r = getaddrinfo(host, service, &hints, servinfo);
if (r != 0) {
fprintf(stderr, "getaddrinfo: %s\n", gai_strerror(r));
return -1;
}
for (p = *servinfo; p != NULL; p = p->ai_next) {
sd = socket(p->ai_family, p->ai_socktype, p->ai_protocol);
if (sd == -1) {
perror("socket");
continue;
}
break;
}
if (p == NULL) {
fputs("Failed to bind socket\n", stderr);
return -1;
} else {
*theirs = p;
return sd;
}
}
/*
* Encode a frame of audio and send it over the network
*/
static int send_audio(snd_pcm_t *snd, CELTEncoder *encoder,
int sd, struct addrinfo *theirs, seq_t *seq)
{
float *pcm;
void *packet, *encoded;
ssize_t z;
snd_pcm_sframes_t f;
pcm = alloca(sizeof(float) * DEFAULT_FRAME * DEFAULT_CHANNELS);
packet = alloca(ENCODED_BYTES + sizeof(uint32_t));
encoded = packet + sizeof(uint32_t);
f = snd_pcm_readi(snd, pcm, DEFAULT_FRAME);
if (f < 0) {
aerror("snd_pcm_readi", f);
return -1;
}
if (f < DEFAULT_FRAME)
fprintf(stderr, "Short read, %ld\n", f);
z = celt_encode_float(encoder, pcm, NULL, encoded, ENCODED_BYTES);
if (z < 0) {
fputs("celt_encode_float failed\n", stderr);
return -1;
}
*(uint32_t*)packet = htonl(*seq);
(*seq)++;
z = sendto(sd, packet, sizeof(uint32_t) + ENCODED_BYTES, 0,
theirs->ai_addr, theirs->ai_addrlen);
if (z == -1) {
perror("sendto");
return -1;
}
fputc('>', stderr);
return 0;
}
static int run_tx(snd_pcm_t *snd, CELTEncoder *encoder,
int sd, struct addrinfo *theirs)
{
seq_t seq = 0;
for (;;) {
int r;
r = send_audio(snd, encoder, sd, theirs, &seq);
if (r == -1)
return -1;
}
}
static void usage(FILE *fd)
{
fprintf(fd, "Usage: tx [<parameters>] <host>\n");
fprintf(fd, "\nAudio device (ALSA) parameters:\n");
fprintf(fd, " -d <device> Device name (default '%s')\n",
DEFAULT_DEVICE);
fprintf(fd, " -m <ms> Buffer time (milliseconds, default %d)\n",
DEFAULT_BUFFER);
fprintf(fd, "\nNetwork parameters:\n");
fprintf(fd, " -p <port> UDP port number or name (default %s)\n",
DEFAULT_SERVICE);
fprintf(fd, " -f <bytes> Frame size (default %d)\n",
DEFAULT_FRAME);
fprintf(fd, "\nEncoding parameters:\n");
fprintf(fd, " -r <rate> Sample rate (default %d)\n",
DEFAULT_RATE);
fprintf(fd, " -c <n> Number of channels (default %d)\n",
DEFAULT_CHANNELS);
fprintf(fd, " -b <bitrate> Bitrate (kbps, approx., default %d)\n",
DEFAULT_BITRATE);
}
int main(int argc, char *argv[])
{
int sd, r;
struct addrinfo *servinfo, *theirs;
snd_pcm_t *snd;
CELTMode *mode;
CELTEncoder *encoder;
/* command-line options */
const char *device = DEFAULT_DEVICE,
*service = DEFAULT_SERVICE,
*host;
unsigned int buffer = DEFAULT_BUFFER,
rate = DEFAULT_RATE,
channels = DEFAULT_CHANNELS;
size_t frame = DEFAULT_FRAME;
for (;;) {
int c;
c = getopt(argc, argv, "c:d:f:m:p:r:");
if (c == -1)
break;
switch (c) {
case 'c':
channels = atoi(optarg);
break;
case 'd':
device = optarg;
break;
case 'f':
frame = atol(optarg);
break;
case 'm':
buffer = atoi(optarg);
break;
case 'p':
service = optarg;
break;
case 'r':
rate = atoi(optarg);
break;
default:
usage(stderr);
return -1;
}
}
if (argv[optind] == NULL) {
usage(stderr);
return -1;
}
host = argv[optind];
mode = celt_mode_create(rate, channels, frame, NULL);
if (mode == NULL) {
fputs("celt_mode_create failed\n", stderr);
return -1;
}
encoder = celt_encoder_create(mode);
if (encoder == NULL) {
fputs("celt_encoder_create failed\n", stderr);
return -1;
}
sd = bind_to_network(host, service, &servinfo, &theirs);
if (sd == -1)
return -1;
r = snd_pcm_open(&snd, device, SND_PCM_STREAM_CAPTURE, 0);
if (r < 0) {
aerror("snd_pcm_open", r);
return -1;
}
if (set_alsa_hw(snd, rate, channels, buffer * 1000) == -1)
return -1;
if (set_alsa_sw(snd) == -1)
return -1;
if (go_realtime() != 0)
return -1;
r = run_tx(snd, encoder, sd, theirs);
freeaddrinfo(servinfo);
if (snd_pcm_close(snd) < 0)
abort();
celt_encoder_destroy(encoder);
celt_mode_destroy(mode);
if (close(sd) == -1)
abort();
return r;
}