mirror of
https://github.com/alsa-project/alsa-lib.git
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263 lines
7.3 KiB
C
263 lines
7.3 KiB
C
/*
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* PCM timer layer
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*/
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int pcard = 0;
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int pdevice = 0;
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int pfragment_size = 4096;
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void set_format(snd_pcm_t *phandle)
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{
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int err;
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snd_pcm_format_t format;
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bzero(&format, sizeof(format));
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format.format = SND_PCM_SFMT_S16_LE;
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format.channels = 2;
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format.rate = 44100;
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if ((err = snd_pcm_playback_format(phandle, &format)) < 0) {
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fprintf(stderr, "Playback format error: %s\n", snd_strerror(err));
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exit(0);
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}
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}
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void set_fragment(snd_pcm_t *phandle)
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{
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int err;
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snd_pcm_playback_params_t pparams;
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bzero(&pparams, sizeof(pparams));
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pparams.fragment_size = pfragment_size;
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pparams.fragments_max = -1; /* maximum */
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pparams.fragments_room = 1;
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if ((err = snd_pcm_playback_params(phandle, &pparams)) < 0) {
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fprintf(stderr, "Fragment setup error: %s\n", snd_strerror(err));
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exit(0);
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}
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}
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void show_playback_status(snd_pcm_t *phandle)
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{
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int err;
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snd_pcm_playback_status_t pstatus;
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if ((err = snd_pcm_playback_status(phandle, &pstatus)) < 0) {
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fprintf(stderr, "Playback status error: %s\n", snd_strerror(err));
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exit(0);
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}
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printf("Playback status\n");
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printf(" Real rate : %u\n", pstatus.rate);
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printf(" Fragments : %i\n", pstatus.fragments);
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printf(" Fragment size : %i\n", pstatus.fragment_size);
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}
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/*
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* Simple event sender
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*/
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void event_sender_start_timer(snd_seq_t *handle, int client, int queue, snd_pcm_t *phandle)
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{
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int err;
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snd_seq_event_t ev;
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if (phandle) {
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snd_pcm_playback_info_t pinfo;
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snd_seq_queue_timer_t qtimer;
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if ((err = snd_pcm_playback_info(phandle, &pinfo)) < 0) {
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fprintf(stderr, "Playback info error: %s\n", snd_strerror(err));
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exit(0);
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}
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bzero(&qtimer, sizeof(qtimer));
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qtimer.type = SND_SEQ_TIMER_MASTER;
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/* note: last bit from subdevices specifies playback */
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/* or capture direction for the timer specification */
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qtimer.number = SND_TIMER_PCM(pcard, pdevice, pinfo.subdevice << 1);
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if ((err = snd_seq_set_queue_timer(handle, queue, &qtimer)) < 0) {
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fprintf(stderr, "Sequencer PCM timer setup failed: %s\n", snd_strerror(err));
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exit(0);
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}
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}
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bzero(&ev, sizeof(ev));
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ev.source.queue = queue;
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ev.source.client = client;
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ev.source.port = 0;
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ev.dest.queue = queue;
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ev.dest.client = SND_SEQ_CLIENT_SYSTEM;
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ev.dest.port = SND_SEQ_PORT_SYSTEM_TIMER;
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ev.flags = SND_SEQ_TIME_STAMP_REAL | SND_SEQ_TIME_MODE_REL;
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ev.type = SND_SEQ_EVENT_START;
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if ((err = snd_seq_event_output(handle, &ev))<0)
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fprintf(stderr, "Timer event output error: %s\n", snd_strerror(err));
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/* ugly, but working */
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while (snd_seq_flush_output(handle)>0)
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sleep(1);
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}
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void event_sender_filter(snd_seq_t *handle)
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{
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int err;
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snd_seq_client_info_t info;
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if ((err = snd_seq_get_client_info(handle, &info)) < 0) {
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fprintf(stderr, "Unable to get client info: %s\n", snd_strerror(err));
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return;
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}
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info.filter = SND_SEQ_FILTER_USE_EVENT;
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memset(&info.event_filter, 0, sizeof(info.event_filter));
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snd_seq_set_bit(SND_SEQ_EVENT_ECHO, info.event_filter);
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if ((err = snd_seq_set_client_info(handle, &info)) < 0) {
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fprintf(stderr, "Unable to set client info: %s\n", snd_strerror(err));
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return;
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}
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}
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void send_event(snd_seq_t *handle, int queue, int client, int port,
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snd_seq_port_subscribe_t *sub, int *time)
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{
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int err;
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snd_seq_event_t ev;
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bzero(&ev, sizeof(ev));
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ev.source.queue = ev.dest.queue = queue;
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ev.source.client = ev.dest.client = client;
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ev.source.port = ev.dest.port = port;
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ev.flags = SND_SEQ_TIME_STAMP_REAL | SND_SEQ_TIME_MODE_ABS;
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ev.time.real.tv_sec = *time; (*time)++;
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ev.type = SND_SEQ_EVENT_ECHO;
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if ((err = snd_seq_event_output(handle, &ev))<0)
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fprintf(stderr, "Event output error: %s\n", snd_strerror(err));
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ev.dest.client = sub->dest.client;
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ev.dest.port = sub->dest.port;
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ev.dest.channel = 0;
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ev.type = SND_SEQ_EVENT_NOTE;
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ev.data.note.note = 64 + (queue*2);
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ev.data.note.velocity = 127;
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ev.data.note.duration = 500; /* 0.5sec */
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if ((err = snd_seq_event_output(handle, &ev))<0)
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fprintf(stderr, "Event output error: %s\n", snd_strerror(err));
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if ((err = snd_seq_flush_output(handle))<0)
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fprintf(stderr, "Event flush error: %s\n", snd_strerror(err));
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}
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void event_sender(snd_seq_t *handle, int argc, char *argv[])
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{
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snd_seq_event_t *ev;
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snd_seq_port_info_t port;
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snd_seq_port_subscribe_t sub;
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fd_set out, in;
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int client, queue, max, err, v1, v2, time = 0, first, pcm_flag = 0;
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char *ptr;
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snd_pcm_t *phandle = NULL;
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char *pbuf = NULL;
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if (argc < 1) {
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fprintf(stderr, "Invalid destonation...\n");
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return;
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}
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if ((client = snd_seq_client_id(handle))<0) {
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fprintf(stderr, "Cannot determine client number: %s\n", snd_strerror(client));
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return;
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}
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printf("Client ID = %i\n", client);
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if ((queue = snd_seq_alloc_queue(handle))<0) {
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fprintf(stderr, "Cannot allocate queue: %s\n", snd_strerror(queue));
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return;
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}
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printf("Queue ID = %i\n", queue);
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event_sender_filter(handle);
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if ((err = snd_seq_block_mode(handle, 0))<0)
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fprintf(stderr, "Cannot set nonblock mode: %s\n", snd_strerror(err));
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bzero(&port, sizeof(port));
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strcpy(port.name, "Output");
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if ((err = snd_seq_create_port(handle, &port)) < 0) {
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fprintf(stderr, "Cannot create output port: %s\n", snd_strerror(err));
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return;
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}
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bzero(&sub, sizeof(sub));
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sub.sender.queue = queue;
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sub.sender.client = client;
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sub.sender.port = port.port;
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sub.dest.queue = queue;
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sub.exclusive = 0;
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for (max = 0; max < argc; max++) {
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ptr = argv[max];
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if (!ptr)
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continue;
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if (!strcmp(ptr, "pcm")) {
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pcm_flag = 1;
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continue;
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}
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if (sscanf(ptr, "%i.%i", &v1, &v2) != 2) {
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fprintf(stderr, "Wrong argument '%s'...\n", argv[max]);
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return;
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}
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sub.dest.client = v1;
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sub.dest.port = v2;
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if ((err = snd_seq_subscribe_port(handle, &sub))<0) {
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fprintf(stderr, "Cannot subscribe port %i from client %i: %s\n", v2, v1, snd_strerror(err));
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return;
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}
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}
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printf("Destonation client = %i, port = %i\n", sub.dest.client, sub.dest.port);
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if (pcm_flag) {
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if ((err = snd_pcm_open(&phandle, pcard, pdevice, SND_PCM_OPEN_PLAYBACK)) < 0) {
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fprintf(stderr, "Playback open error: %s\n", snd_strerror(err));
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exit(0);
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}
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set_format(phandle);
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set_fragment(phandle);
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show_playback_status(phandle);
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pbuf = calloc(1, pfragment_size);
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if (pbuf == NULL) {
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fprintf(stderr, "No enough memory...\n");
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exit(0);
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}
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}
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event_sender_start_timer(handle, client, queue, phandle);
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first = 1;
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while (1) {
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FD_ZERO(&out);
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FD_ZERO(&in);
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max = snd_seq_file_descriptor(handle);
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FD_SET(snd_seq_file_descriptor(handle), &out);
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FD_SET(snd_seq_file_descriptor(handle), &in);
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if (phandle) {
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if (snd_pcm_file_descriptor(phandle) > max)
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max = snd_pcm_file_descriptor(phandle);
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FD_SET(snd_pcm_file_descriptor(phandle), &out);
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}
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if (select(max + 1, &in, &out, NULL, NULL) < 0)
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break;
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if (phandle && FD_ISSET(snd_pcm_file_descriptor(phandle), &out)) {
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if (snd_pcm_write(phandle, pbuf, pfragment_size) != pfragment_size) {
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fprintf(stderr, "Playback write error!!\n");
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exit(0);
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}
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}
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if (FD_ISSET(snd_seq_file_descriptor(handle), &out)) {
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if (first) {
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send_event(handle, queue, client, port.port, &sub, &time);
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first = 0;
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}
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}
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if (FD_ISSET(snd_seq_file_descriptor(handle), &in)) {
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do {
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if ((err = snd_seq_event_input(handle, &ev))<0)
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break;
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if (!ev)
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continue;
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if (ev->type == SND_SEQ_EVENT_ECHO)
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send_event(handle, queue, client, port.port, &sub, &time);
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decode_event(ev);
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snd_seq_free_event(ev);
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} while (err > 0);
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}
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}
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}
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