mmm, your tips works well but there's something that I don't understand: the gst_util_uint64_scale_int could be in this way : ts = gst_util_uint64_scale_int (frame_num * GST_SECOND, FPS_NUM,  FPS_DEN); and not: ts = gst_util_uint64_scale_int (frame_num * GST_SECOND, FPS_DEN,  FPS_NUM); But if I use the first form the gst-app doesn't works (the image are freeze). Someone can explain why? <div> 2007/6/15, Riccardo Corona <<a href="mailto:coronariccardo@gmail.com">coronariccardo@gmail.com</a>>:<blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;"> YES!It works!Now the example about fakesrc in the manual could be change with a new one that not lead the cpu to 100% and that give a fps choice. Moreover it seems to works also with ffdec_mpeg for my problem but it's too early to scream like a child... Anyway, thank you! <div>2007/6/15, Tim Muller <<a href="mailto:t.i.m@zen.co.uk" target="_blank" onclick="return top.js.OpenExtLink(window,event,this)">t.i.m@zen.co.uk</a>>: <div><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;"> Riccardo Corona <<a href="mailto:coronariccardo@gmail.com" target="_blank" onclick="return top.js.OpenExtLink(window,event,this)">coronariccardo@gmail.com</a>> wrote : > How can I set the duration on the buffer? For testing purposes, try something like this for timestamps and durations (and get rid of the GstClock/currenttime stuff): /* framerate (assumed to be fixed) */ #define FPS_NUM 25 #define FPS_DEN 1 static guint frame_num = 0; GstClockTime ts, next_ts; ts = gst_util_uint64_scale_int (frame_num * GST_SECOND, FPS_DEN, FPS_NUM); next_ts = gst_util_uint64_scale_int ((frame_num + 1) * GST_SECOND, FPS_DEN, FPS_NUM); GST_BUFFER_TIMESTAMP (buf) = ts; GST_BUFFER_DURATION (buf) = next_ts - ts; ++frame_num; This assumes a fixed framerate. Cheers   -Tim </blockquote></div></div> -- Riccardo Corona </blockquote></div> -- Riccardo Corona