rtsp.c

vlc源码

    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++;
    }
}