if( what )    {        buf = strdup(what);    }    else    {        buf = malloc( strlen(rtsp->p_private->host) +                      strlen(rtsp->p_private->path) + 16 );        sprintf( buf, "rtsp://%s:%i/%s", rtsp->p_private->host,                 rtsp->p_private->port, rtsp->p_private->path );    }    rtsp_send_request( rtsp, "SET_PARAMETER", buf );    free( buf );    return rtsp_get_answers( rtsp );}int rtsp_request_play( rtsp_client_t *rtsp, const char *what ){    char *buf;    if( what )    {        buf = strdup( what );    }    else    {        buf = malloc( strlen(rtsp->p_private->host) +                      strlen(rtsp->p_private->path) + 16 );        sprintf( buf, "rtsp://%s:%i/%s", rtsp->p_private->host,                 rtsp->p_private->port, rtsp->p_private->path );    }    rtsp_send_request( rtsp, "PLAY", buf );    free( buf );    return rtsp_get_answers( rtsp );}int rtsp_request_tearoff( rtsp_client_t *rtsp, const char *what ){    rtsp_send_request( rtsp, "TEAROFF", what );    return rtsp_get_answers( rtsp );}/* * read opaque data from stream */int rtsp_read_data( rtsp_client_t *rtsp, uint8_t *buffer, unsigned int size ){    int i, seq;    if( size >= 4 )    {        i = rtsp->pf_read( rtsp->p_userdata, (uint8_t*)buffer, (unsigned int) 4 );        if( i < 4 ) return i;        if( buffer[0]=='S' && buffer[1]=='E' && buffer[2]=='T' &&            buffer[3]=='_' )        {            char *rest = rtsp_get( rtsp );            if( !rest ) return -1;            seq = -1;            do            {                free( rest );                rest = rtsp_get( rtsp );                if( !rest ) return -1;                if( !strncasecmp( rest, "Cseq:", 5 ) )                    sscanf( rest, "%*s %u", &seq );            } while( *rest );            free( rest );            if( seq < 0 )            {                //fprintf(stderr, "warning: cseq not recognized!\n");                seq = 1;            }            /* lets make the server happy */            rtsp_put( rtsp, "RTSP/1.0 451 Parameter Not Understood" );            rest = malloc(17);            sprintf( rest,"CSeq: %u", seq );            rtsp_put( rtsp, rest );            rtsp_put( rtsp, "" );            free( rest );            i = rtsp->pf_read( rtsp->p_userdata, (unsigned char*)buffer, size );        }        else        {            i = rtsp->pf_read( rtsp->p_userdata, (unsigned char*)buffer + 4, size - 4 );            i += 4;        }    }    else i = rtsp->pf_read( rtsp->p_userdata, (unsigned char*)buffer, size );    //fprintf( stderr, "<< %d of %d bytes\n", i, size );    return i;}/* * connect to a rtsp server */int rtsp_connect( rtsp_client_t *rtsp, const char *psz_mrl,                  const char *psz_user_agent ){    rtsp_t *s;    char *mrl_ptr;    char *slash, *colon;    unsigned int hostend, pathbegin, i;    if( !psz_mrl ) return -1;    s = malloc( sizeof(rtsp_t) );    rtsp->p_private = s;    if( !strncmp( psz_mrl, "rtsp://", 7 ) ) psz_mrl += 7;    mrl_ptr = strdup( psz_mrl );    for( i=0; i<MAX_FIELDS; i++ )    {        s->answers[i]=NULL;        s->scheduled[i]=NULL;    }    s->host = NULL;    s->port = 554; /* rtsp standard port */    s->path = NULL;    s->mrl  = strdup(psz_mrl);    s->server = NULL;    s->server_state = 0;    s->server_caps = 0;    s->cseq = 0;    s->session = NULL;    if( psz_user_agent ) s->user_agent = strdup( psz_user_agent );    else s->user_agent = strdup( "User-Agent: RealMedia Player Version "                                 "6.0.9.1235 (linux-2.0-libc6-i386-gcc2.95)" );    slash = strchr( mrl_ptr, '/' );    colon = strchr( mrl_ptr, ':' );    if( !slash ) slash = mrl_ptr + strlen(mrl_ptr) + 1;    if( !colon ) colon = slash;    if( colon > slash ) colon = slash;    pathbegin = slash - mrl_ptr;    hostend = colon - mrl_ptr;    s->host = malloc(hostend+1);    strncpy( s->host, mrl_ptr, hostend );    s->host[hostend] = 0;    if( pathbegin < strlen(mrl_ptr) ) s->path = strdup(mrl_ptr+pathbegin+1);    if( colon != slash )    {        char buffer[pathbegin-hostend];        strncpy( buffer, mrl_ptr+hostend+1, pathbegin-hostend-1 );        buffer[pathbegin-hostend-1] = 0;        s->port = atoi(buffer);        if( s->port < 0 || s->port > 65535 ) s->port = 554;    }    free( mrl_ptr );    //fprintf( stderr, "got mrl: %s %i %s\n", s->host, s->port, s->path );    s->s = rtsp->pf_connect( rtsp->p_userdata, s->host, s->port );    if( s->s < 0 )    {        //fprintf(stderr, "rtsp: failed to connect to '%s'\n", s->host);        rtsp_close( rtsp );        return -1;    }    s->server_state = RTSP_CONNECTED;    /* now lets send an options request. */    rtsp_schedule_field( rtsp, "CSeq: 1");    rtsp_schedule_field( rtsp, s->user_agent);    rtsp_schedule_field( rtsp, "ClientChallenge: "                               "9e26d33f2984236010ef6253fb1887f7");    rtsp_schedule_field( rtsp, "PlayerStarttime: [28/03/2003:22:50:23 00:00]");    rtsp_schedule_field( rtsp, "CompanyID: KnKV4M4I/B2FjJ1TToLycw==" );    rtsp_schedule_field( rtsp, "GUID: 00000000-0000-0000-0000-000000000000" );    rtsp_schedule_field( rtsp, "RegionData: 0" );    rtsp_schedule_field( rtsp, "ClientID: "                               "Linux_2.4_6.0.9.1235_play32_RN01_EN_586" );    /*rtsp_schedule_field( rtsp, "Pragma: initiate-session" );*/    rtsp_request_options( rtsp, NULL );    return 0;}/* * closes an rtsp connection */void rtsp_close( rtsp_client_t *rtsp ){    if( rtsp->p_private->server_state )    {        /* TODO: send a TEAROFF */        rtsp->pf_disconnect( rtsp->p_userdata );    }    free( rtsp->p_private->path );    free( rtsp->p_private->host );    free( rtsp->p_private->mrl );    free( rtsp->p_private->session );    free( rtsp->p_private->user_agent );    free( rtsp->p_private->server );    rtsp_free_answers( rtsp );    rtsp_unschedule_all( rtsp );    free( rtsp->p_private );}/* * search in answers for tags. returns a pointer to the content * after the first matched tag. returns NULL if no match found. */char *rtsp_search_answers( rtsp_client_t *rtsp, const char *tag ){    char **answer;    char *ptr;    if( !rtsp->p_private->answers ) return NULL;    answer = rtsp->p_private->answers;    while(*answer)    {        if( !strncasecmp( *answer, tag, strlen(tag) ) )        {            ptr = strchr(*answer, ':');            ptr++;            while( *ptr == ' ' ) ptr++;            return ptr;        }        answer++;    }    return NULL;}/* * session id management */void rtsp_set_session( rtsp_client_t *rtsp, const char *id ){    free( rtsp->p_private->session );    rtsp->p_private->session = strdup(id);}char *rtsp_get_session( rtsp_client_t *rtsp ){    return rtsp->p_private->session;}char *rtsp_get_mrl( rtsp_client_t *rtsp ){    return rtsp->p_private->mrl;}/* * schedules a field for transmission */void rtsp_schedule_field( rtsp_client_t *rtsp, const char *string ){    int i = 0;    if( !string ) return;    while( rtsp->p_private->scheduled[i] ) i++;    rtsp->p_private->scheduled[i] = strdup(string);}/* * removes the first scheduled field which prefix matches string. */void rtsp_unschedule_field( rtsp_client_t *rtsp, const char *string ){    char **ptr = rtsp->p_private->scheduled;    if( !string ) return;    while( *ptr )    {      if( !strncmp(*ptr, string, strlen(string)) ) break;    }    free( *ptr );    ptr++;    do    {        *(ptr-1) = *ptr;    } while( *ptr );}/* * unschedule all fields */void rtsp_unschedule_all( rtsp_client_t *rtsp ){    char **ptr;    if( !rtsp->p_private->scheduled ) return;    ptr = rtsp->p_private->scheduled;    while( *ptr )    {        free( *ptr );        *ptr = NULL;        ptr++;    }}/* * free answers */void rtsp_free_answers( rtsp_client_t *rtsp ){    char **answer;    if( !rtsp->p_private->answers ) return;    answer = rtsp->p_private->answers;    while( *answer )    {        free( *answer );        *answer = NULL;        answer++;    }}