<html> <head> <meta content="text/html; charset=ISO-8859-1" http-equiv="Content-Type"> </head> <body bgcolor="#FFFFFF" text="#000000"> <div class="moz-cite-prefix">Le 2014-09-05 10:12, Paul Barber a écrit : </div> <blockquote cite="mid:5409C4C1.40606@oncology.ox.ac.uk" type="cite">I have written a source plugin for the VRMagic USB frame grabber (VRMAVC-2), and for the lowest latency I can configure it to send me individual fields at 50 fps (each half-frame height). I would like to have a downstream element that will combine these fields (e.g. weave them) into a full frame, still at 50 fps. Does such an element or sink exist? </blockquote> Sorry to maybe ask a silly question, but if you combine frames coming at 50fps into pairs (top/bottom field), the best rate you can have at it's output would be 25fps no ? Other then that, normally if you set <meta http-equiv="content-type" content="text/html; charset=ISO-8859-1"> <span style="color: rgb(0, 0, 0); font-family: monospace; font-size: medium; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: rgb(255, 255, 255); display: inline !important; float: none;">GST_BUFFER_FLAG_ONEFIELD, and mark the top field buffer with the GST_BUFFER_FLAG_TFF, deinterlace should be able to operate on an 50fps input stream (but will output deinterlaced buffers at 25fps, hence operate with 1/50s latency). To get rid of the latency, you would need some display HW/API that can receive and scannout the half frames as they come. cheers, Nicolas <span style="color: rgb(0, 0, 0); font-family: monospace; font-size: medium; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: rgb(255, 255, 255); display: inline !important; float: none;"> </body> </html>