rtsp.c

/*
 * RTSP/SDP client
 * Copyright (c) 2002 Fabrice Bellard
 *
 * 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 "libavutil/base64.h"
#include "libavutil/avstring.h"
#include "libavutil/intreadwrite.h"
#include "avformat.h"

#include <sys/time.h>
#if HAVE_SYS_SELECT_H
#include <sys/select.h>
#endif
#include <strings.h>
#include "internal.h"
#include "network.h"
#include "os_support.h"
#include "rtsp.h"

#include "rtpdec.h"
#include "rdt.h"
#include "rtpdec_asf.h"
#include "rtpdec_vorbis.h"

//#define DEBUG
//#define DEBUG_RTP_TCP

#if LIBAVFORMAT_VERSION_INT < (53 << 16)
int rtsp_default_protocols = (1 << RTSP_LOWER_TRANSPORT_UDP);
#endif

#define SPACE_CHARS " \t\r\n"
/* we use memchr() instead of strchr() here because strchr() will return
 * the terminating '\0' of SPACE_CHARS instead of NULL if c is '\0'. */
#define redir_isspace(c) memchr(SPACE_CHARS, c, 4)
static void skip_spaces(const char **pp)
{
    const char *p;
    p = *pp;
    while (redir_isspace(*p))
        p++;
    *pp = p;
}

static void get_word_until_chars(char *buf, int buf_size,
                                 const char *sep, const char **pp)
{
    const char *p;
    char *q;

    p = *pp;
    skip_spaces(&p);
    q = buf;
    while (!strchr(sep, *p) && *p != '\0') {
        if ((q - buf) < buf_size - 1)
            *q++ = *p;
        p++;
    }
    if (buf_size > 0)
        *q = '\0';
    *pp = p;
}

static void get_word_sep(char *buf, int buf_size, const char *sep,
                         const char **pp)
{
    if (**pp == '/') (*pp)++;
    get_word_until_chars(buf, buf_size, sep, pp);
}

static void get_word(char *buf, int buf_size, const char **pp)
{
    get_word_until_chars(buf, buf_size, SPACE_CHARS, pp);
}

/* parse the rtpmap description: <codec_name>/<clock_rate>[/<other params>] */
static int sdp_parse_rtpmap(AVFormatContext *s,
                            AVCodecContext *codec, RTSPStream *rtsp_st,
                            int payload_type, const char *p)
{
    char buf[256];
    int i;
    AVCodec *c;
    const char *c_name;

    /* Loop into AVRtpDynamicPayloadTypes[] and AVRtpPayloadTypes[] and
     * see if we can handle this kind of payload.
     * The space should normally not be there but some Real streams or
     * particular servers ("RealServer Version 6.1.3.970", see issue 1658)
     * have a trailing space. */
    get_word_sep(buf, sizeof(buf), "/ ", &p);
    if (payload_type >= RTP_PT_PRIVATE) {
        RTPDynamicProtocolHandler *handler;
        for (handler = RTPFirstDynamicPayloadHandler;
             handler; handler = handler->next) {
            if (!strcasecmp(buf, handler->enc_name) &&
                codec->codec_type == handler->codec_type) {
                codec->codec_id          = handler->codec_id;
                rtsp_st->dynamic_handler = handler;
                if (handler->open)
                    rtsp_st->dynamic_protocol_context = handler->open();
                break;
            }
        }
    } else {
        /* We are in a standard case
         * (from http://www.iana.org/assignments/rtp-parameters). */
        /* search into AVRtpPayloadTypes[] */
        codec->codec_id = ff_rtp_codec_id(buf, codec->codec_type);
    }

    c = avcodec_find_decoder(codec->codec_id);
    if (c && c->name)
        c_name = c->name;
    else
        c_name = "(null)";

    get_word_sep(buf, sizeof(buf), "/", &p);
    i = atoi(buf);
    switch (codec->codec_type) {
    case CODEC_TYPE_AUDIO:
        av_log(s, AV_LOG_DEBUG, "audio codec set to: %s\n", c_name);
        codec->sample_rate = RTSP_DEFAULT_AUDIO_SAMPLERATE;
        codec->channels = RTSP_DEFAULT_NB_AUDIO_CHANNELS;
        if (i > 0) {
            codec->sample_rate = i;
            get_word_sep(buf, sizeof(buf), "/", &p);
            i = atoi(buf);
            if (i > 0)
                codec->channels = i;
            // TODO: there is a bug here; if it is a mono stream, and
            // less than 22000Hz, faad upconverts to stereo and twice
            // the frequency.  No problem, but the sample rate is being
            // set here by the sdp line. Patch on its way. (rdm)
        }
        av_log(s, AV_LOG_DEBUG, "audio samplerate set to: %i\n",
               codec->sample_rate);
        av_log(s, AV_LOG_DEBUG, "audio channels set to: %i\n",
               codec->channels);
        break;
    case CODEC_TYPE_VIDEO:
        av_log(s, AV_LOG_DEBUG, "video codec set to: %s\n", c_name);
        break;
    default:
        break;
    }
    return 0;
}

/* return the length and optionally the data */
static int hex_to_data(uint8_t *data, const char *p)
{
    int c, len, v;

    len = 0;
    v = 1;
    for (;;) {
        skip_spaces(&p);
        if (*p == '\0')
            break;
        c = toupper((unsigned char) *p++);
        if (c >= '0' && c <= '9')
            c = c - '0';
        else if (c >= 'A' && c <= 'F')
            c = c - 'A' + 10;
        else
            break;
        v = (v << 4) | c;
        if (v & 0x100) {
            if (data)
                data[len] = v;
            len++;
            v = 1;
        }
    }
    return len;
}

static void sdp_parse_fmtp_config(AVCodecContext * codec, void *ctx,
                                  char *attr, char *value)
{
    switch (codec->codec_id) {
    case CODEC_ID_MPEG4:
    case CODEC_ID_AAC:
        if (!strcmp(attr, "config")) {
            /* decode the hexa encoded parameter */
            int len = hex_to_data(NULL, value);
            if (codec->extradata)
                av_free(codec->extradata);
            codec->extradata = av_mallocz(len + FF_INPUT_BUFFER_PADDING_SIZE);
            if (!codec->extradata)
                return;
            codec->extradata_size = len;
            hex_to_data(codec->extradata, value);
        }
        break;
    case CODEC_ID_VORBIS:
        ff_vorbis_parse_fmtp_config(codec, ctx, attr, value);
        break;
    default:
        break;
    }
    return;
}

typedef struct {
    const char *str;
    uint16_t    type;
    uint32_t    offset;
} AttrNameMap;

/* All known fmtp parmeters and the corresping RTPAttrTypeEnum */
#define ATTR_NAME_TYPE_INT 0
#define ATTR_NAME_TYPE_STR 1
static const AttrNameMap attr_names[]=
{
    { "SizeLength",       ATTR_NAME_TYPE_INT,
      offsetof(RTPPayloadData, sizelength) },
    { "IndexLength",      ATTR_NAME_TYPE_INT,
      offsetof(RTPPayloadData, indexlength) },
    { "IndexDeltaLength", ATTR_NAME_TYPE_INT,
      offsetof(RTPPayloadData, indexdeltalength) },
    { "profile-level-id", ATTR_NAME_TYPE_INT,
      offsetof(RTPPayloadData, profile_level_id) },
    { "StreamType",       ATTR_NAME_TYPE_INT,
      offsetof(RTPPayloadData, streamtype) },
    { "mode",             ATTR_NAME_TYPE_STR,
      offsetof(RTPPayloadData, mode) },
    { NULL, -1, -1 },
};

/* parse the attribute line from the fmtp a line of an sdp resonse. This
 * is broken out as a function because it is used in rtp_h264.c, which is
 * forthcoming. */
int ff_rtsp_next_attr_and_value(const char **p, char *attr, int attr_size,
                                char *value, int value_size)
{
    skip_spaces(p);
    if (**p) {
        get_word_sep(attr, attr_size, "=", p);
        if (**p == '=')
            (*p)++;
        get_word_sep(value, value_size, ";", p);
        if (**p == ';')
            (*p)++;
        return 1;
    }
    return 0;
}

/* parse a SDP line and save stream attributes */
static void sdp_parse_fmtp(AVStream *st, const char *p)
{
    char attr[256];
    /* Vorbis setup headers can be up to 12KB and are sent base64
     * encoded, giving a 12KB * (4/3) = 16KB FMTP line. */
    char value[16384];
    int i;
    RTSPStream *rtsp_st = st->priv_data;
    AVCodecContext *codec = st->codec;
    RTPPayloadData *rtp_payload_data = &rtsp_st->rtp_payload_data;

    /* loop on each attribute */
    while (ff_rtsp_next_attr_and_value(&p, attr, sizeof(attr),
                                       value, sizeof(value))) {
        /* grab the codec extra_data from the config parameter of the fmtp
         * line */
        sdp_parse_fmtp_config(codec, rtsp_st->dynamic_protocol_context,
                              attr, value);
        /* Looking for a known attribute */
        for (i = 0; attr_names[i].str; ++i) {
            if (!strcasecmp(attr, attr_names[i].str)) {
                if (attr_names[i].type == ATTR_NAME_TYPE_INT) {
                    *(int *)((char *)rtp_payload_data +
                        attr_names[i].offset) = atoi(value);
                } else if (attr_names[i].type == ATTR_NAME_TYPE_STR)
                    *(char **)((char *)rtp_payload_data +
                        attr_names[i].offset) = av_strdup(value);
            }
        }
    }
}

/** Parse a string p in the form of Range:npt=xx-xx, and determine the start
 *  and end time.
 *  Used for seeking in the rtp stream.
 */
static void rtsp_parse_range_npt(const char *p, int64_t *start, int64_t *end)
{
    char buf[256];

    skip_spaces(&p);
    if (!av_stristart(p, "npt=", &p))
        return;

    *start = AV_NOPTS_VALUE;
    *end = AV_NOPTS_VALUE;

    get_word_sep(buf, sizeof(buf), "-", &p);
    *start = parse_date(buf, 1);
    if (*p == '-') {
        p++;
        get_word_sep(buf, sizeof(buf), "-", &p);
        *end = parse_date(buf, 1);
    }
//    av_log(NULL, AV_LOG_DEBUG, "Range Start: %lld\n", *start);
//    av_log(NULL, AV_LOG_DEBUG, "Range End: %lld\n", *end);
}

typedef struct SDPParseState {
    /* SDP only */
    struct in_addr default_ip;
    int            default_ttl;
    int            skip_media;  ///< set if an unknown m= line occurs
} SDPParseState;

static void sdp_parse_line(AVFormatContext *s, SDPParseState *s1,
                           int letter, const char *buf)
{
    RTSPState *rt = s->priv_data;
    char buf1[64], st_type[64];
    const char *p;
    enum CodecType codec_type;
    int payload_type, i;
    AVStream *st;
    RTSPStream *rtsp_st;
    struct in_addr sdp_ip;
    int ttl;

    dprintf(s, "sdp: %c='%s'\n", letter, buf);

    p = buf;
    if (s1->skip_media && letter != 'm')
        return;
    switch (letter) {
    case 'c':
        get_word(buf1, sizeof(buf1), &p);
        if (strcmp(buf1, "IN") != 0)
            return;
        get_word(buf1, sizeof(buf1), &p);
        if (strcmp(buf1, "IP4") != 0)
            return;
        get_word_sep(buf1, sizeof(buf1), "/", &p);
        if (ff_inet_aton(buf1, &sdp_ip) == 0)
            return;
        ttl = 16;
        if (*p == '/') {
            p++;
            get_word_sep(buf1, sizeof(buf1), "/", &p);
            ttl = atoi(buf1);
        }
        if (s->nb_streams == 0) {
            s1->default_ip = sdp_ip;
            s1->default_ttl = ttl;
        } else {
            st = s->streams[s->nb_streams - 1];
            rtsp_st = st->priv_data;
            rtsp_st->sdp_ip = sdp_ip;
            rtsp_st->sdp_ttl = ttl;
        }
        break;
    case 's':
        av_metadata_set(&s->metadata, "title", p);
        break;
    case 'i':
        if (s->nb_streams == 0) {
            av_metadata_set(&s->metadata, "comment", p);
            break;
        }
        break;
    case 'm':
        /* new stream */
        s1->skip_media = 0;
        get_word(st_type, sizeof(st_type), &p);
        if (!strcmp(st_type, "audio")) {
            codec_type = CODEC_TYPE_AUDIO;
        } else if (!strcmp(st_type, "video")) {
            codec_type = CODEC_TYPE_VIDEO;
        } else if (!strcmp(st_type, "application")) {
            codec_type = CODEC_TYPE_DATA;
        } else {
            s1->skip_media = 1;
            return;
        }
        rtsp_st = av_mallocz(sizeof(RTSPStream));
        if (!rtsp_st)
            return;
        rtsp_st->stream_index = -1;
        dynarray_add(&rt->rtsp_streams, &rt->nb_rtsp_streams, rtsp_st);

        rtsp_st->sdp_ip = s1->default_ip;
        rtsp_st->sdp_ttl = s1->default_ttl;

        get_word(buf1, sizeof(buf1), &p); /* port */
        rtsp_st->sdp_port = atoi(buf1);

        get_word(buf1, sizeof(buf1), &p); /* protocol (ignored) */

        /* XXX: handle list of formats */
        get_word(buf1, sizeof(buf1), &p); /* format list */
        rtsp_st->sdp_payload_type = atoi(buf1);

        if (!strcmp(ff_rtp_enc_name(rtsp_st->sdp_payload_type), "MP2T")) {
            /* no corresponding stream */
        } else {
            st = av_new_stream(s, 0);
            if (!st)
                return;
            st->priv_data = rtsp_st;
            rtsp_st->stream_index = st->index;
            st->codec->codec_type = codec_type;
            if (rtsp_st->sdp_payload_type < RTP_PT_PRIVATE) {
                /* if standard payload type, we can find the codec right now */
                ff_rtp_get_codec_info(st->codec, rtsp_st->sdp_payload_type);
            }
        }
        /* put a default control url */
        av_strlcpy(rtsp_st->control_url, rt->control_uri,
                   sizeof(rtsp_st->control_url));
        break;
    case 'a':
        if (av_strstart(p, "control:", &p)) {
            if (s->nb_streams == 0) {
                if (!strncmp(p, "rtsp://", 7))
                    av_strlcpy(rt->control_uri, p,
                               sizeof(rt->control_uri));
            } else {
            char proto[32];
            /* get the control url */
            st = s->streams[s->nb_streams - 1];
            rtsp_st = st->priv_data;

            /* XXX: may need to add full url resolution */
            ff_url_split(proto, sizeof(proto), NULL, 0, NULL, 0,
                         NULL, NULL, 0, p);
            if (proto[0] == '\0') {
                /* relative control URL */
                if (rtsp_st->control_url[strlen(rtsp_st->control_url)-1]!='/')
                av_strlcat(rtsp_st->control_url, "/",
                           sizeof(rtsp_st->control_url));
                av_strlcat(rtsp_st->control_url, p,
                           sizeof(rtsp_st->control_url));
            } else
                av_strlcpy(rtsp_st->control_url, p,
                           sizeof(rtsp_st->control_url));
            }
        } else if (av_strstart(p, "rtpmap:", &p) && s->nb_streams > 0) {
            /* NOTE: rtpmap is only supported AFTER the 'm=' tag */
            get_word(buf1, sizeof(buf1), &p);
            payload_type = atoi(buf1);
            st = s->streams[s->nb_streams - 1];
            rtsp_st = st->priv_data;
            sdp_parse_rtpmap(s, st->codec, rtsp_st, payload_type, p);
        } else if (av_strstart(p, "fmtp:", &p)) {
            /* NOTE: fmtp is only supported AFTER the 'a=rtpmap:xxx' tag */
            get_word(buf1, sizeof(buf1), &p);
            payload_type = atoi(buf1);
            for (i = 0; i < s->nb_streams; i++) {
                st      = s->streams[i];
                rtsp_st = st->priv_data;
                if (rtsp_st->sdp_payload_type == payload_type) {
                    if (!(rtsp_st->dynamic_handler &&
                          rtsp_st->dynamic_handler->parse_sdp_a_line &&
                          rtsp_st->dynamic_handler->parse_sdp_a_line(s,
                              i, rtsp_st->dynamic_protocol_context, buf)))
                        sdp_parse_fmtp(st, p);
                }
            }
        } else if (av_strstart(p, "framesize:", &p)) {
            // let dynamic protocol handlers have a stab at the line.
            get_word(buf1, sizeof(buf1), &p);
            payload_type = atoi(buf1);
            for (i = 0; i < s->nb_streams; i++) {
                st      = s->streams[i];
                rtsp_st = st->priv_data;
                if (rtsp_st->sdp_payload_type == payload_type &&
                    rtsp_st->dynamic_handler &&
                    rtsp_st->dynamic_handler->parse_sdp_a_line)
                    rtsp_st->dynamic_handler->parse_sdp_a_line(s, i,
                        rtsp_st->dynamic_protocol_context, buf);
            }
        } else if (av_strstart(p, "range:", &p)) {
            int64_t start, end;

            // this is so that seeking on a streamed file can work.
            rtsp_parse_range_npt(p, &start, &end);
            s->start_time = start;
            /* AV_NOPTS_VALUE means live broadcast (and can't seek) */
            s->duration   = (end == AV_NOPTS_VALUE) ?
                            AV_NOPTS_VALUE : end - start;
        } else if (av_strstart(p, "IsRealDataType:integer;",&p)) {
            if (atoi(p) == 1)
                rt->transport = RTSP_TRANSPORT_RDT;
        } else {
            if (rt->server_type == RTSP_SERVER_WMS)
                ff_wms_parse_sdp_a_line(s, p);
            if (s->nb_streams > 0) {
                if (rt->server_type == RTSP_SERVER_REAL)
                    ff_real_parse_sdp_a_line(s, s->nb_streams - 1, p);

                rtsp_st = s->streams[s->nb_streams - 1]->priv_data;
                if (rtsp_st->dynamic_handler &&
                    rtsp_st->dynamic_handler->parse_sdp_a_line)
                    rtsp_st->dynamic_handler->parse_sdp_a_line(s,
                        s->nb_streams - 1,
                        rtsp_st->dynamic_protocol_context, buf);
            }
        }
        break;
    }
}

static int sdp_parse(AVFormatContext *s, const char *content)
{
    const char *p;
    int letter;
    /* Some SDP lines, particularly for Realmedia or ASF RTSP streams,
     * contain long SDP lines containing complete ASF Headers (several
     * kB) or arrays of MDPR (RM stream descriptor) headers plus
     * "rulebooks" describing their properties. Therefore, the SDP line
     * buffer is large.
     *
     * The Vorbis FMTP line can be up to 16KB - see sdp_parse_fmtp. */
    char buf[16384], *q;
    SDPParseState sdp_parse_state, *s1 = &sdp_parse_state;

    memset(s1, 0, sizeof(SDPParseState));
    p = content;
    for (;;) {
        skip_spaces(&p);
        letter = *p;
        if (letter == '\0')
            break;
        p++;
        if (*p != '=')
            goto next_line;
        p++;
        /* get the content */
        q = buf;
        while (*p != '\n' && *p != '\r' && *p != '\0') {
            if ((q - buf) < sizeof(buf) - 1)
                *q++ = *p;
            p++;
        }
        *q = '\0';
        sdp_parse_line(s, s1, letter, buf);
    next_line:
        while (*p != '\n' && *p != '\0')
            p++;
        if (*p == '\n')
            p++;
    }
    return 0;
}

/* close and free RTSP streams */
void ff_rtsp_close_streams(AVFormatContext *s)
{
    RTSPState *rt = s->priv_data;
    int i;
    RTSPStream *rtsp_st;

    for (i = 0; i < rt->nb_rtsp_streams; i++) {
        rtsp_st = rt->rtsp_streams[i];
        if (rtsp_st) {
            if (rtsp_st->transport_priv) {
                if (s->oformat) {
                    AVFormatContext *rtpctx = rtsp_st->transport_priv;
                    av_write_trailer(rtpctx);
                    if (rt->lower_transport == RTSP_LOWER_TRANSPORT_TCP) {
                        uint8_t *ptr;
                        url_close_dyn_buf(rtpctx->pb, &ptr);
                        av_free(ptr);
                    } else {
                        url_fclose(rtpctx->pb);
                    }
                    av_metadata_free(&rtpctx->streams[0]->metadata);
                    av_metadata_free(&rtpctx->metadata);
                    av_free(rtpctx->streams[0]);
                    av_free(rtpctx);
                } else if (rt->transport == RTSP_TRANSPORT_RDT)
                    ff_rdt_parse_close(rtsp_st->transport_priv);
                else
                    rtp_parse_close(rtsp_st->transport_priv);
            }
            if (rtsp_st->rtp_handle)
                url_close(rtsp_st->rtp_handle);
            if (rtsp_st->dynamic_handler && rtsp_st->dynamic_protocol_context)
                rtsp_st->dynamic_handler->close(
                    rtsp_st->dynamic_protocol_context);
        }
    }
    av_free(rt->rtsp_streams);
    if (rt->asf_ctx) {
        av_close_input_stream (rt->asf_ctx);
        rt->asf_ctx = NULL;
    }
}

static void *rtsp_rtp_mux_open(AVFormatContext *s, AVStream *st,
                               URLContext *handle)
{
    RTSPState *rt = s->priv_data;
    AVFormatContext *rtpctx;
    int ret;
    AVOutputFormat *rtp_format = av_guess_format("rtp", NULL, NULL);

    if (!rtp_format)
        return NULL;

    /* Allocate an AVFormatContext for each output stream */
    rtpctx = avformat_alloc_context();
    if (!rtpctx)
        return NULL;

    rtpctx->oformat = rtp_format;
    if (!av_new_stream(rtpctx, 0)) {
        av_free(rtpctx);
        return NULL;
    }
    /* Copy the max delay setting; the rtp muxer reads this. */
    rtpctx->max_delay = s->max_delay;
    /* Copy other stream parameters. */
    rtpctx->streams[0]->sample_aspect_ratio = st->sample_aspect_ratio;

    /* Set the synchronized start time. */
    rtpctx->start_time_realtime = rt->start_time;

    /* Remove the local codec, link to the original codec
     * context instead, to give the rtp muxer access to
     * codec parameters. */
    av_free(rtpctx->streams[0]->codec);
    rtpctx->streams[0]->codec = st->codec;

    if (handle) {
        url_fdopen(&rtpctx->pb, handle);
    } else
        url_open_dyn_packet_buf(&rtpctx->pb, RTSP_TCP_MAX_PACKET_SIZE);
    ret = av_write_header(rtpctx);

    if (ret) {
        if (handle) {
            url_fclose(rtpctx->pb);
        } else {
            uint8_t *ptr;
            url_close_dyn_buf(rtpctx->pb, &ptr);
            av_free(ptr);
        }
        av_free(rtpctx->streams[0]);
        av_free(rtpctx);
        return NULL;
    }

    /* Copy the RTP AVStream timebase back to the original AVStream */
    st->time_base = rtpctx->streams[0]->time_base;
    return rtpctx;
}

static int rtsp_open_transport_ctx(AVFormatContext *s, RTSPStream *rtsp_st)
{
    RTSPState *rt = s->priv_data;
    AVStream *st = NULL;

    /* open the RTP context */
    if (rtsp_st->stream_index >= 0)
        st = s->streams[rtsp_st->stream_index];
    if (!st)
        s->ctx_flags |= AVFMTCTX_NOHEADER;

    if (s->oformat) {
        rtsp_st->transport_priv = rtsp_rtp_mux_open(s, st, rtsp_st->rtp_handle);
        /* Ownage of rtp_handle is passed to the rtp mux context */
        rtsp_st->rtp_handle = NULL;
    } else if (rt->transport == RTSP_TRANSPORT_RDT)
        rtsp_st->transport_priv = ff_rdt_parse_open(s, st->index,
                                            rtsp_st->dynamic_protocol_context,
                                            rtsp_st->dynamic_handler);
    else
        rtsp_st->transport_priv = rtp_parse_open(s, st, rtsp_st->rtp_handle,
                                         rtsp_st->sdp_payload_type,
                                         &rtsp_st->rtp_payload_data);

    if (!rtsp_st->transport_priv) {
         return AVERROR(ENOMEM);
    } else if (rt->transport != RTSP_TRANSPORT_RDT) {
        if (rtsp_st->dynamic_handler) {
            rtp_parse_set_dynamic_protocol(rtsp_st->transport_priv,
                                           rtsp_st->dynamic_protocol_context,
                                           rtsp_st->dynamic_handler);
        }
    }

    return 0;
}

#if CONFIG_RTSP_DEMUXER || CONFIG_RTSP_MUXER
static int rtsp_probe(AVProbeData *p)
{
    if (av_strstart(p->filename, "rtsp:", NULL))
        return AVPROBE_SCORE_MAX;
    return 0;
}

static void rtsp_parse_range(int *min_ptr, int *max_ptr, const char **pp)
{
    const char *p;
    int v;

    p = *pp;
    skip_spaces(&p);
    v = strtol(p, (char **)&p, 10);
    if (*p == '-') {
        p++;
        *min_ptr = v;
        v = strtol(p, (char **)&p, 10);
        *max_ptr = v;
    } else {
        *min_ptr = v;
        *max_ptr = v;
    }
    *pp = p;
}

/* XXX: only one transport specification is parsed */
static void rtsp_parse_transport(RTSPMessageHeader *reply, const char *p)
{
    char transport_protocol[16];
    char profile[16];
    char lower_transport[16];
    char parameter[16];
    RTSPTransportField *th;
    char buf[256];

    reply->nb_transports = 0;

    for (;;) {
        skip_spaces(&p);
        if (*p == '\0')
            break;

        th = &reply->transports[reply->nb_transports];

        get_word_sep(transport_protocol, sizeof(transport_protocol),
                     "/", &p);
        if (!strcasecmp (transport_protocol, "rtp")) {
            get_word_sep(profile, sizeof(profile), "/;,", &p);
            lower_transport[0] = '\0';
            /* rtp/avp/<protocol> */
            if (*p == '/') {
                get_word_sep(lower_transport, sizeof(lower_transport),
                             ";,", &p);
            }
            th->transport = RTSP_TRANSPORT_RTP;
        } else if (!strcasecmp (transport_protocol, "x-pn-tng") ||
                   !strcasecmp (transport_protocol, "x-real-rdt")) {
            /* x-pn-tng/<protocol> */
            get_word_sep(lower_transport, sizeof(lower_transport), "/;,", &p);
            profile[0] = '\0';
            th->transport = RTSP_TRANSPORT_RDT;
        }
        if (!strcasecmp(lower_transport, "TCP"))
            th->lower_transport = RTSP_LOWER_TRANSPORT_TCP;
        else
            th->lower_transport = RTSP_LOWER_TRANSPORT_UDP;

        if (*p == ';')
            p++;
        /* get each parameter */
        while (*p != '\0' && *p != ',') {
            get_word_sep(parameter, sizeof(parameter), "=;,", &p);
            if (!strcmp(parameter, "port")) {
                if (*p == '=') {
                    p++;
                    rtsp_parse_range(&th->port_min, &th->port_max, &p);
                }
            } else if (!strcmp(parameter, "client_port")) {
                if (*p == '=') {
                    p++;
                    rtsp_parse_range(&th->client_port_min,
                                     &th->client_port_max, &p);
                }
            } else if (!strcmp(parameter, "server_port")) {
                if (*p == '=') {
                    p++;
                    rtsp_parse_range(&th->server_port_min,
                                     &th->server_port_max, &p);
                }
            } else if (!strcmp(parameter, "interleaved")) {
                if (*p == '=') {
                    p++;
                    rtsp_parse_range(&th->interleaved_min,
                                     &th->interleaved_max, &p);
                }
            } else if (!strcmp(parameter, "multicast")) {
                if (th->lower_transport == RTSP_LOWER_TRANSPORT_UDP)
                    th->lower_transport = RTSP_LOWER_TRANSPORT_UDP_MULTICAST;
            } else if (!strcmp(parameter, "ttl")) {
                if (*p == '=') {
                    p++;
                    th->ttl = strtol(p, (char **)&p, 10);
                }
            } else if (!strcmp(parameter, "destination")) {
                struct in_addr ipaddr;

                if (*p == '=') {
                    p++;
                    get_word_sep(buf, sizeof(buf), ";,", &p);
                    if (ff_inet_aton(buf, &ipaddr))
                        th->destination = ntohl(ipaddr.s_addr);
                }
            }
            while (*p != ';' && *p != '\0' && *p != ',')
                p++;
            if (*p == ';')
                p++;
        }
        if (*p == ',')
            p++;

        reply->nb_transports++;
    }
}

void ff_rtsp_parse_line(RTSPMessageHeader *reply, const char *buf,
                        HTTPAuthState *auth_state)
{
    const char *p;

    /* NOTE: we do case independent match for broken servers */
    p = buf;
    if (av_stristart(p, "Session:", &p)) {
        int t;
        get_word_sep(reply->session_id, sizeof(reply->session_id), ";", &p);
        if (av_stristart(p, ";timeout=", &p) &&
            (t = strtol(p, NULL, 10)) > 0) {
            reply->timeout = t;
        }
    } else if (av_stristart(p, "Content-Length:", &p)) {
        reply->content_length = strtol(p, NULL, 10);
    } else if (av_stristart(p, "Transport:", &p)) {
        rtsp_parse_transport(reply, p);
    } else if (av_stristart(p, "CSeq:", &p)) {
        reply->seq = strtol(p, NULL, 10);
    } else if (av_stristart(p, "Range:", &p)) {
        rtsp_parse_range_npt(p, &reply->range_start, &reply->range_end);
    } else if (av_stristart(p, "RealChallenge1:", &p)) {
        skip_spaces(&p);
        av_strlcpy(reply->real_challenge, p, sizeof(reply->real_challenge));
    } else if (av_stristart(p, "Server:", &p)) {
        skip_spaces(&p);
        av_strlcpy(reply->server, p, sizeof(reply->server));
    } else if (av_stristart(p, "Notice:", &p) ||
               av_stristart(p, "X-Notice:", &p)) {
        reply->notice = strtol(p, NULL, 10);
    } else if (av_stristart(p, "Location:", &p)) {
        skip_spaces(&p);
        av_strlcpy(reply->location, p , sizeof(reply->location));
    } else if (av_stristart(p, "WWW-Authenticate:", &p) && auth_state) {
        skip_spaces(&p);
        ff_http_auth_handle_header(auth_state, "WWW-Authenticate", p);
    } else if (av_stristart(p, "Authentication-Info:", &p) && auth_state) {
        skip_spaces(&p);
        ff_http_auth_handle_header(auth_state, "Authentication-Info", p);
    }
}

/* skip a RTP/TCP interleaved packet */
void ff_rtsp_skip_packet(AVFormatContext *s)
{
    RTSPState *rt = s->priv_data;
    int ret, len, len1;
    uint8_t buf[1024];

    ret = url_read_complete(rt->rtsp_hd, buf, 3);
    if (ret != 3)
        return;
    len = AV_RB16(buf + 1);

    dprintf(s, "skipping RTP packet len=%d\n", len);

    /* skip payload */
    while (len > 0) {
        len1 = len;
        if (len1 > sizeof(buf))
            len1 = sizeof(buf);
        ret = url_read_complete(rt->rtsp_hd, buf, len1);
        if (ret != len1)
            return;
        len -= len1;
    }
}

int ff_rtsp_read_reply(AVFormatContext *s, RTSPMessageHeader *reply,
                       unsigned char **content_ptr,
                       int return_on_interleaved_data)
{
    RTSPState *rt = s->priv_data;
    char buf[4096], buf1[1024], *q;
    unsigned char ch;
    const char *p;
    int ret, content_length, line_count = 0;
    unsigned char *content = NULL;

    memset(reply, 0, sizeof(*reply));

    /* parse reply (XXX: use buffers) */
    rt->last_reply[0] = '\0';
    for (;;) {
        q = buf;
        for (;;) {
            ret = url_read_complete(rt->rtsp_hd, &ch, 1);
#ifdef DEBUG_RTP_TCP
            dprintf(s, "ret=%d c=%02x [%c]\n", ret, ch, ch);
#endif
            if (ret != 1)
                return -1;
            if (ch == '\n')
                break;
            if (ch == '$') {
                /* XXX: only parse it if first char on line ? */
                if (return_on_interleaved_data) {
                    return 1;
                } else
                    ff_rtsp_skip_packet(s);
            } else if (ch != '\r') {
                if ((q - buf) < sizeof(buf) - 1)
                    *q++ = ch;
            }
        }
        *q = '\0';

        dprintf(s, "line='%s'\n", buf);

        /* test if last line */
        if (buf[0] == '\0')
            break;
        p = buf;
        if (line_count == 0) {
            /* get reply code */
            get_word(buf1, sizeof(buf1), &p);
            get_word(buf1, sizeof(buf1), &p);
            reply->status_code = atoi(buf1);
        } else {
            ff_rtsp_parse_line(reply, p, &rt->auth_state);
            av_strlcat(rt->last_reply, p,    sizeof(rt->last_reply));
            av_strlcat(rt->last_reply, "\n", sizeof(rt->last_reply));
        }
        line_count++;
    }

    if (rt->session_id[0] == '\0' && reply->session_id[0] != '\0')
        av_strlcpy(rt->session_id, reply->session_id, sizeof(rt->session_id));

    content_length = reply->content_length;
    if (content_length > 0) {
        /* leave some room for a trailing '\0' (useful for simple parsing) */
        content = av_malloc(content_length + 1);
        (void)url_read_complete(rt->rtsp_hd, content, content_length);
        content[content_length] = '\0';
    }
    if (content_ptr)
        *content_ptr = content;
    else
        av_free(content);

    if (rt->seq != reply->seq) {
        av_log(s, AV_LOG_WARNING, "CSeq %d expected, %d received.\n",
            rt->seq, reply->seq);
    }

    /* EOS */
    if (reply->notice == 2101 /* End-of-Stream Reached */      ||
        reply->notice == 2104 /* Start-of-Stream Reached */    ||
        reply->notice == 2306 /* Continuous Feed Terminated */) {
        rt->state = RTSP_STATE_IDLE;
    } else if (reply->notice >= 4400 && reply->notice < 5500) {
        return AVERROR(EIO); /* data or server error */
    } else if (reply->notice == 2401 /* Ticket Expired */ ||
             (reply->notice >= 5500 && reply->notice < 5600) /* end of term */ )
        return AVERROR(EPERM);

    return 0;
}