rtp-rawaudio.c

spook是一个linux下开源的流媒体服务器

/*
 * Copyright (C) 2004 Nathan Lutchansky <[e-mail]>
 *
 * This program 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.
 *
 * This program 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 this program; if not, write to the Free Software Foundation,
 * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 */

#include <sys/types.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <sys/time.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <fcntl.h>
#include <errno.h>

#include <event.h>
#include <log.h>
#include <frame.h>
#include <stream.h>
#include <outputs.h>
#include <rtp.h>
#include <rtp_media.h>
#include <conf_parse.h>

struct rtp_rawaudio {
	unsigned char *rawaudio_data;
	int rawaudio_len;
	int format;
	int sampsize;
	int channels;
	int rate;
	int ts_incr;
	unsigned int timestamp;
};

static int rawaudio_get_sdp( char *dest, int len, int payload,
					int port, void *d )
{
	struct rtp_rawaudio *out = (struct rtp_rawaudio *)d;

	switch( out->format )
	{
	case FORMAT_PCM:
		if( out->rate == 44100 && out->channels == 2 )
			return snprintf( dest, len,
					"m=audio %d RTP/AVP 10\r\n", port );
		else if( out->rate == 44100 && out->channels == 1 )
			return snprintf( dest, len,
					"m=audio %d RTP/AVP 11\r\n", port );
		else
			return snprintf( dest, len, "m=audio %d RTP/AVP %d\r\na=rtpmap:%d L16/%d/%d\r\n", port, payload, payload, out->rate, out->channels );
		break;
	case FORMAT_ALAW:
		if( out->rate == 8000 && out->channels == 1 )
			return snprintf( dest, len,
					"m=audio %d RTP/AVP 8\r\n", port );
		else
			return snprintf( dest, len, "m=audio %d RTP/AVP %d\r\na=rtpmap:%d PCMA/%d/%d\r\n", port, payload, payload, out->rate, out->channels );
		break;
	}
	return -1;
}

static int rawaudio_get_payload( int payload, void *d )
{
	struct rtp_rawaudio *out = (struct rtp_rawaudio *)d;

	switch( out->format )
	{
	case FORMAT_PCM:
		if( out->rate == 44100 && out->channels == 2 )
			return 10;
		else if( out->rate == 44100 && out->channels == 1 )
			return 11;
		else return payload;
		break;
	case FORMAT_ALAW:
		if( out->rate == 8000 && out->channels == 1 )
			return 8;
		else return payload;
		break;
	}
	return -1;
}

static int rawaudio_process_frame( struct frame *f, void *d )
{
	struct rtp_rawaudio *out = (struct rtp_rawaudio *)d;

	out->timestamp += out->rawaudio_len / out->channels / out->sampsize;
	out->rawaudio_data = f->d;
	out->rawaudio_len = f->length;

	return 1; /* always ready! */
}

static int rawaudio_send( struct rtp_endpoint *ep, void *d )
{
	struct rtp_rawaudio *out = (struct rtp_rawaudio *)d;
	int i, plen;
	struct iovec v[2];

	for( i = 0; i < out->rawaudio_len; i += plen )
	{
		plen = out->rawaudio_len - i;
		if( plen > ep->max_data_size )
		{
			plen = ep->max_data_size;
			plen -= plen % ( out->channels * out->sampsize );
		}
		v[1].iov_base = out->rawaudio_data + i;
		v[1].iov_len = plen;
		if( send_rtp_packet( ep, v, 2,
			    out->timestamp + i / out->channels / out->sampsize,
			    0 ) < 0 )
			return -1;
	}
	return 0;
}

struct rtp_media *new_rtp_media_rawaudio_stream( struct stream *stream )
{
	struct rtp_rawaudio *out;

	out = (struct rtp_rawaudio *)malloc( sizeof( struct rtp_rawaudio ) );
	out->rawaudio_len = 0;
	stream->get_framerate( stream, &out->channels, &out->rate );
	out->rate /= out->channels;
	out->format = stream->format;
	out->sampsize = out->format == FORMAT_PCM ? 2 : 1;
	out->ts_incr = 0;
	out->timestamp = 0;

	return new_rtp_media( rawaudio_get_sdp, rawaudio_get_payload,
			rawaudio_process_frame, rawaudio_send, out );
}