read_h26l.c

linuxUNIX下跑的一套服务端程序

/* * 
 *  $Id: read_H26L.c 133 2005-05-09 17:35:14Z federico $
 *  
 *  This file is part of Fenice
 *
 *  Fenice -- Open Media Server
 *
 *  Copyright (C) 2004 by
 *  	
 *	- Giampaolo Mancini	<[e-mail]>
 *	- Francesco Varano	<[e-mail]>
 *	- Marco Penno		<[e-mail]>
 *	- Federico Ridolfo	<[e-mail]>
 *	- Eugenio Menegatti 	<[e-mail]>
 *	- Stefano Cau
 *	- Giuliano Emma
 *	- Stefano Oldrini
 * 
 *  Fenice is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  Fenice is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with Fenice; if not, write to the Free Software
 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *  
 * */

#include <stdio.h>
#include <unistd.h>
#include <string.h>
#include <fcntl.h>

#include <fenice/types.h>
#include <fenice/utils.h>
#include <fenice/mediainfo.h>
#include <fenice/h26l.h>

int read_H26L (media_entry *me, uint8 *data, uint32 *data_size, double *mtime, int *recallme, uint8 *marker)
{
	int ret;
        unsigned char intime[4];
        unsigned char h26l_header[12];
	static_H26L *s=NULL;

	*marker=0;
									/* At this point it should be right to find the nearest lower frame */
        								/* computing it from the value of mtime */
        if (!(me->flags & ME_FD)) {                                     /* and starting the reading from this */
		if ( (ret=mediaopen(me)) < 0 )
			return ret;
		s = (static_H26L *) calloc (1, sizeof(static_H26L));
		me->stat = (void *) s;
		s->pkt_sent=0;
        } else 
		s = (static_H26L *) me->stat;


        if (s->pkt_sent==0)        {
        lseek(me->fd,0,SEEK_SET);
        read(me->fd,&(s->bufsize),4);              				/* The H26L RTP-Stream has 4 bytes for the size and 4 bytes for the intime */
        read(me->fd,&intime,4);
        read(me->fd,&h26l_header,12);                                   /* Then there is the RTP-Header */
        s->current_timestamp = h26l_header[4] | (h26l_header[5] <<8) | (h26l_header[6] <<16) | (h26l_header[7] <<24);
        }

        *data_size=s->bufsize-12;
        //*data=(unsigned char *)calloc(1,*data_size);
        //if (*data==NULL) {
        //        return ERR_ALLOC;
        //}
        if (read(me->fd,&(data[0]),*data_size)<=0) {
                s->pkt_sent=0;
                return ERR_EOF;
        }

        read(me->fd,&s->bufsize,4);                                        /* reads next packet to have next time-stamp */
        read(me->fd,&intime,4);
        read(me->fd,&h26l_header,12);
        s->next_timestamp = h26l_header[4] | (h26l_header[5] <<8) | (h26l_header[6] <<16) | (h26l_header[7] <<24);

        if (s->current_timestamp == s->next_timestamp)        {               /* If the time-stamps are the same then next-packet belongs to the same */
                *recallme = 1;                                          /* frame and the scheduler hasn't to wait to send it */
        } else  {
                *recallme = 0;
        }

        if (*recallme == 0) {                                                           /* to compute the new value of mtime for the next call of readH26L */
		me->description.delta_mtime = ((s->next_timestamp - s->current_timestamp)/1000)*me->description.pkt_len;
        }

        *mtime = (s->current_timestamp * me->description.pkt_len)/1000;    		/* to compute the time-stamp */
        s->pkt_sent++;
        s->current_timestamp = s->next_timestamp;
        return ERR_NOERROR;
}