<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 TRANSITIONAL//EN"> <HTML> <HEAD> <META HTTP-EQUIV="Content-Type" CONTENT="text/html; CHARSET=UTF-8"> <META NAME="GENERATOR" CONTENT="GtkHTML/4.6.6"> </HEAD> <BODY> Le jeudi 24 avril 2014 à 10:54 +0900, Makoto Harada a écrit : <BLOCKQUOTE TYPE=CITE> <PRE> Dear gstreamer expert, I'm now working to implement DMABUF feature to our custom video encoder plugin, which would be directory connected to v4l2src in the gstreamer pipeline. (We have already validated the DMABUF functionality of our kernel by using some simple V4L2 applications, so now the turn of gstreamer) </PRE> </BLOCKQUOTE> This is not needed. I already got it in my branch [1]. Next week I'm giving it a last debugging round, need to fix some threading issues and seeking/flush. Some patch cleanup and will start merging this into master if it's all good with the others. What will be pending is transparent activation of it. <BLOCKQUOTE TYPE=CITE> <PRE> I've checked the DMABUF related commits of git repository including two commits below, and also checked the discussion regarding DMABUF on this mailing list. <A HREF="https://bugzilla.gnome.org/show_bug.cgi?id=693826">https://bugzilla.gnome.org/show_bug.cgi?id=693826</A> <A HREF="http://lists.freedesktop.org/archives/gstreamer-commits/2013-February/069408.html">http://lists.freedesktop.org/archives/gstreamer-commits/2013-February/069408.html</A> On top of that, I have two questions. 1. How the information of file descriptor of DMABUF memory, which is allocated by VIDIOC_EXPBUF ioctl, is expected to transfer to the downstream element, and how the downstream element is expected to receive it ? I've checked gstdmabuf.c and gstdmabuf.h in gst-plugins-base, however could not find such kind of information. </PRE> </BLOCKQUOTE> So the branch I mention has a new GstV4l2Allocator, that is used internally to track v4l2 buffers and associated memory. What we do to fit the dmabuf allocator model, is that we do the expbuf using gst_v4l2_allocator_alloc_dmabuf(), allocation a v4l2 memory and make this memory parent a of normally allocatoted dmabuf memory. The dmabuf memory are then put into a buffer and forwarded. Other element can detect that all memory are dmabuf by iterating the memory and using gst_is_dmabuf_memory (). <BLOCKQUOTE TYPE=CITE> <PRE> 2. Does anyone know if there is any working gstreamer plugin which acts as the DMABUF importer, and works with v4l2src ? </PRE> </BLOCKQUOTE> With my work, any v4l2 element can do this by setting io-mode=dmabuf-import (or the capture/output varient for m2m). <BLOCKQUOTE TYPE=CITE> <PRE> I'm newbie of gstreamer world, so any kinds of information would be helpful. </PRE> </BLOCKQUOTE> Hope my work will make your life simplier then, nothing of this was exactly simple. I think there exist patches to wayland sink to add dmabuf support, though I don't know if it's importation or exportation (probably the second). cheers, Nicolas </BODY> </HTML>