PeerStreamer

/*

 * RTSP muxer

 * Copyright (c) 2010 Martin Storsjo

 *

 * This file is part of FFmpeg.

 *

 * FFmpeg is free software; you can redistribute it and/or

 * modify it under the terms of the GNU Lesser General Public

 * License as published by the Free Software Foundation; either

 * version 2.1 of the License, or (at your option) any later version.

 *

 * FFmpeg 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

 * Lesser General Public License for more details.

 *

 * You should have received a copy of the GNU Lesser General Public

 * License along with FFmpeg; if not, write to the Free Software

 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA

 */

#include "avformat.h"

#include <sys/time.h>

#if HAVE_SYS_SELECT_H

#include <sys/select.h>

#endif

#include "network.h"

#include "rtsp.h"

#include <libavutil/intreadwrite.h>

static int rtsp_write_record(AVFormatContext *s)

{

    RTSPState *rt = s->priv_data;

    RTSPMessageHeader reply1, *reply = &reply1;

    char cmd[1024];

    snprintf(cmd, sizeof(cmd),

             "RECORD %s RTSP/1.0\r\n"

             "Range: npt=%0.3f-\r\n",

             rt->control_uri,

             (double) 0);

    ff_rtsp_send_cmd(s, cmd, reply, NULL);

    if (reply->status_code != RTSP_STATUS_OK)

        return -1;

    rt->state = RTSP_STATE_STREAMING;

    return 0;

}

static int rtsp_write_header(AVFormatContext *s)

{

    RTSPState *rt = s->priv_data;

    int ret;

    ret = ff_rtsp_connect(s);

    if (ret)

        return ret;

    if (rtsp_write_record(s) < 0) {

        ff_rtsp_close_streams(s);

        url_close(rt->rtsp_hd);

        return AVERROR_INVALIDDATA;

    }

    return 0;

}

static int tcp_write_packet(AVFormatContext *s, RTSPStream *rtsp_st)

{

    RTSPState *rt = s->priv_data;

    AVFormatContext *rtpctx = rtsp_st->transport_priv;

    uint8_t *buf, *ptr;

    int size;

    uint8_t interleave_header[4];

    size = url_close_dyn_buf(rtpctx->pb, &buf);

    ptr = buf;

    while (size > 4) {

        uint32_t packet_len = AV_RB32(ptr);

        int id;

        ptr += 4;

        size -= 4;

        if (packet_len > size || packet_len < 2)

            break;

        if (ptr[1] >= 200 && ptr[1] <= 204)

            id = rtsp_st->interleaved_max; /* RTCP */

        else

            id = rtsp_st->interleaved_min; /* RTP */

        interleave_header[0] = '$';

        interleave_header[1] = id;

        AV_WB16(interleave_header + 2, packet_len);

        url_write(rt->rtsp_hd, interleave_header, 4);

        url_write(rt->rtsp_hd, ptr, packet_len);

        ptr += packet_len;

        size -= packet_len;

    }

    av_free(buf);

    url_open_dyn_packet_buf(&rtpctx->pb, RTSP_TCP_MAX_PACKET_SIZE);

    return 0;

}

static int rtsp_write_packet(AVFormatContext *s, AVPacket *pkt)

{

    RTSPState *rt = s->priv_data;

    RTSPStream *rtsp_st;

    fd_set rfds;

    int n, tcp_fd;

    struct timeval tv;

    AVFormatContext *rtpctx;

    AVPacket local_pkt;

    int ret;

    tcp_fd = url_get_file_handle(rt->rtsp_hd);

    while (1) {

        FD_ZERO(&rfds);

        FD_SET(tcp_fd, &rfds);

        tv.tv_sec = 0;

        tv.tv_usec = 0;

        n = select(tcp_fd + 1, &rfds, NULL, NULL, &tv);

        if (n <= 0)

            break;

        if (FD_ISSET(tcp_fd, &rfds)) {

            RTSPMessageHeader reply;

            /* Don't let ff_rtsp_read_reply handle interleaved packets,

             * since it would block and wait for an RTSP reply on the socket

             * (which may not be coming any time soon) if it handles

             * interleaved packets internally. */

            ret = ff_rtsp_read_reply(s, &reply, NULL, 1);

            if (ret < 0)

                return AVERROR(EPIPE);

            if (ret == 1)

                ff_rtsp_skip_packet(s);

            /* XXX: parse message */

            if (rt->state != RTSP_STATE_STREAMING)

                return AVERROR(EPIPE);

        }

    }

    if (pkt->stream_index < 0 || pkt->stream_index >= rt->nb_rtsp_streams)

        return AVERROR_INVALIDDATA;

    rtsp_st = rt->rtsp_streams[pkt->stream_index];

    rtpctx = rtsp_st->transport_priv;

    /* Use a local packet for writing to the chained muxer, otherwise

     * the internal stream_index = 0 becomes visible to the muxer user. */

    local_pkt = *pkt;

    local_pkt.stream_index = 0;

    ret = av_write_frame(rtpctx, &local_pkt);

    /* av_write_frame does all the RTP packetization. If using TCP as

     * transport, rtpctx->pb is only a dyn_packet_buf that queues up the

     * packets, so we need to send them out on the TCP connection separately.

     */

    if (!ret && rt->lower_transport == RTSP_LOWER_TRANSPORT_TCP)

        ret = tcp_write_packet(s, rtsp_st);

    return ret;

}

static int rtsp_write_close(AVFormatContext *s)

{

    RTSPState *rt = s->priv_data;

    char cmd[1024];

    snprintf(cmd, sizeof(cmd),

             "TEARDOWN %s RTSP/1.0\r\n",

             rt->control_uri);

    ff_rtsp_send_cmd_async(s, cmd);

    ff_rtsp_close_streams(s);

    url_close(rt->rtsp_hd);

    ff_network_close();

    return 0;

}

AVOutputFormat rtsp_muxer = {

    "rtsp",

    NULL_IF_CONFIG_SMALL("RTSP output format"),

    NULL,

    NULL,

    sizeof(RTSPState),

    CODEC_ID_PCM_MULAW,

    CODEC_ID_NONE,

    rtsp_write_header,

    rtsp_write_packet,

    rtsp_write_close,

    .flags = AVFMT_NOFILE | AVFMT_GLOBALHEADER,

};