synstreamon.c

linux环境下用纯c写的RTP协议的通用开发库

/*-------------------------------------------------------------------------
 * synstreamon.c - synstreamon
 *-------------------------------------------------------------------------
 */

#include <syn.h>
#include <stdlib.h>
#include <strings.h>
#include <util.h>
#include <sample.h>

/*------------------------------------------------------------------------
 * synstreamon - turn on a stream a synchronization layer. Clkrt is the 
 * stream's media clockrate in Hz. Parameters is a type-specific (e.g., 
 * sample, frame, or packet) structure that contains type-specific 
 * parameters.
 *------------------------------------------------------------------------
 */
int
synstreamon(struct synsession *pssn, ssrc_t ssrc, int type, int clkrt, mediatime_t jitthresh, void *parameters)
{

	struct synstream	*psstm;
	unsigned int		leeway;

	/*
	 * Check that the stream still exists at the 
	 * RTP layer. I.e., we did not miss a timedout
	 * event.
	 */
	if (rtpctl(pssn->ssn_session, RTP_CTL_STREAM_NULL, NULL, 0, ssrc) == ERROR)
	  return ERROR;

	if ((psstm = malloc(sizeof(struct synstream))) == NULL)
		return ERROR;
	memset(psstm, 0, sizeof(struct synstream));

	/*
	 * Turn on the events needed for the stream at
	 * the synchronization layer.
	 */
	eventqfilterssrc(&pssn->ssn_events, EVENT_RTP_HEAD, ssrc, TRUE);
	eventqfilterssrc(&pssn->ssn_events, EVENT_RTCP_SDES_CNAME, ssrc, TRUE);
	eventqfilterssrc(&pssn->ssn_events, EVENT_RTCP_BYE, ssrc, TRUE);
	eventqfilterssrc(&pssn->ssn_events, EVENT_PARTICIPANT_TIMEOUT, ssrc, TRUE);
	eventqfilterssrc(&pssn->ssn_events, EVENT_PARTICIPANT_ENCODING, ssrc, TRUE);
	eventqfilterssrc(&pssn->ssn_events, EVENT_PARTICIPANT_SEQGAP, ssrc, TRUE);
	eventqfilterssrc(&pssn->ssn_events, EVENT_RTCP_SR, ssrc, TRUE);
  
	pthread_mutex_init(&psstm->sstm_readmutex, NULL);
	pthread_cond_init(&psstm->sstm_readcond, NULL);

	psstm->sstm_readflags = SYN_READ_FLUSH | SYN_READ_BLOCK;
	psstm->sstm_ssrc = ssrc;
	psstm->sstm_clkrt = clkrt;
	psstm->sstm_type = type;
	psstm->sstm_jitthresh = jitthresh;
	psstm->sstm_parameters = parameters;

	if (htadd(pssn->ssn_ssrcs, ssrc, (void *) psstm) == ERROR) {
		htdel(pssn->ssn_events.eq_ssrcs, psstm->sstm_ssrc);
		free(psstm);
		return ERROR;
	}

	leeway = SYN_DEFAULT_LEEWAY;
	synctl(pssn, SYN_CTL_STREAM_SETLEEWAY, (char *) &leeway, ssrc);

	synrebuffer(pssn, ssrc);

	/*
	 * Turn the stream on at the RTP layer.
	 */
	rtpstreamon(pssn->ssn_session, ssrc, clkrt);
	return OK;
}