Live Stream Encoding

Hi There,

i want to stream some pictures out of my application using the Theora 
codec. I can stream to a socket or a file. The current work based on the 
png2theora example. Something while enconding went wrong: I can see the 
whole video in VLC, but the complete duration of the file will not be 
displayed. If i play the video in Firefox, the first 2 seconds will not 
be played. I think the problem is in the setup of the encoder:

            keyframe_frequency = 0;
            th_info_init(&ti);   
            ti.frame_width = ((480 + 15) >>4)<<4;
            ti.frame_height = ((320 + 15)>>4)<<4;
            ti.pic_width = 480;
            ti.pic_height = 320;
            ti.pic_x = 0;
            ti.pic_y = 0;
            ti.fps_numerator = 30;
            ti.fps_denominator = 1;
            ti.aspect_numerator = 0;
            ti.aspect_denominator = 0;
            ti.colorspace = TH_CS_UNSPECIFIED;
            ti.pixel_fmt = TH_PF_422;
            ti.target_bitrate = -1;
            ti.quality = 48;
            ti.keyframe_granule_shift=ilog(keyframe_frequency-1);


What can cause such a problem?

Regards
Mario