Thank's for the first answer... For the usage of fakesrc simply I've done this: static void cb_handoff (GstElement *fakesrc,         GstBuffer  *buffer,         GstPad     *pad,         gpointer    user_data) {         pad->caps= gst_caps_new_simple ("video/mpeg",         "width", G_TYPE_INT, 720,         "height", G_TYPE_INT, 288,         "framerate",GST_TYPE_FRACTION,1,1,         "mpegversion",G_TYPE_INT,4,         "systemstream",G_TYPE_BOOLEAN,false);     gst_buffer_set_caps(buffer,pad->caps);      //Calling a function that give me an mpeg4 packet ("myMP4packet")  with timestamp its ("myTS")          buffer->timestamp=myTS;     GST_BUFFER_MALLOCDATA(buffer) =    (unsigned char*)g_memdup(myMP4packet->pixel_ptr,  myMP4packet->dimension);      GST_BUFFER_DATA(buffer) = GST_BUFFER_MALLOCDATA(buffer);      GST_BUFFER_SIZE(buffer) = myMP4packet->dimension;      buffer->offset=(unsigned int)(buffer->malloc_data);      buffer->offset_end=(unsigned int)(buffer->malloc_data+buffer->size); } Since it works well only for the first frame, it receive the mpeg4 packet and print it on the directdraw sink, my greater problem is on the buffer->duration (now is set to GST_CLOCK_TIME_NONE). Moreover I can't understand if I need to interact in some way with the "GstElement *fakesrc". <div>2007/6/4, René Stadler <<a href="mailto:mail@renestadler.de">mail@renestadler.de</a>>:<blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;"> Am Montag, den 04.06.2007, 12:46 +0200 schrieb Riccardo Corona: > Hi, > I've a fakesrc handoff function like this in which I get mpeg4 packet > from the net: > > static void cb_handoff (GstElement *fakesrc, >         GstBuffer  *buffer, >         GstPad     *pad, >         gpointer    user_data) > { > ...... > } > > > And here's my doubts: > > 1)The buffer->caps is null, even if i set a capsfilter between my > fakesrc and the next element in the pipeline, I think that it must be > set but if I try something like this: > > .......... > pad->caps= gst_caps_new_simple ("video/mpeg", >         "width", G_TYPE_INT, 720, >         "height", G_TYPE_INT, 288, >         "framerate",GST_TYPE_FRACTION,1,1, >         "mpegversion",G_TYPE_INT,4, >         "systemstream",G_TYPE_BOOLEAN,false); > gst_buffer_set_caps(buffer,pad->caps); > ......... > You shouldn't set pad->caps. > > or like this: > > > ......... > GstPad *myPad; > myPad->caps= gst_caps_new_simple ("video/mpeg", >         "width", G_TYPE_INT, 720, >         "height", G_TYPE_INT, 288, >         "framerate",GST_TYPE_FRACTION,1,1, >         "mpegversion",G_TYPE_INT,4, >         "systemstream",G_TYPE_BOOLEAN,false); > gst_buffer_set_caps(buffer,myPad->caps); > ............ > > My app crash at the gst_caps_new_simple execution.It's hard for me to > say why it crash but my first problem is to understand if is necessary > to set the cap (I think yes) and moreover what can be the utility of > the pads into the handoff function. You seem to ignore an important compiler warning which tells you that you are missing the sentinel.  Append NULL to the argument list. > 2)In my handoff I've compressed data since I get mpeg4 packets so the > buffer->offset would be the byte offset of the first byte in > buffer->malloc, is it right?Is it necessary to set manually the offset > and offset_end or is it done automatically?Offset have strange values > since it starts from 1 but after a few cycle it increments to much > greater values (1,2,3,4,8456,12345...) and offset_end isn't set. > I really can't understand these two vars. > > Any help will be very appreciate. > Thank's and best regards. > > -- > Riccardo Corona Figuring out how you are supposed to interact with fakesrc is so hard because you are not supposed to do it -- have a look at the new appsrc element (found in gst-plugins-bad) or write your own GstBaseSrc or GstPushSrc derived element. -- Regards,   René Stadler </blockquote></div> -- Riccardo Corona