<html> <head> <meta content="text/html; charset=ISO-8859-1" http-equiv="Content-Type"> </head> <body text="#000000" bgcolor="#FFFFFF"> <div class="moz-cite-prefix">Hello, I've tried the codes on your allocator branch [1]. Environment: - Linux version 3.2.0-4-686-pae (<a class="moz-txt-link-abbreviated" href="mailto:debian-kernel@lists.debian.org">debian-kernel@lists.debian.org</a>) (gcc version 4.6.3 (Debian 4.6.3-14) ) #1 SMP Debian 3.2.46-1 - gstreamer1.0, gst-plugins-base are fetched from master branch on official tree (as of 2014/4/30) - gst-plugins-good are fetched from [1] [1] <a class="moz-txt-link-freetext" href="http://cgit.collabora.com/git/user/nicolas/gst-plugins-good.git/log/?h=v4l2-allocator">http://cgit.collabora.com/git/user/nicolas/gst-plugins-good.git/log/?h=v4l2-allocator</a> I've tried the basic operation before trying DMABUF feature. However, unfortunately, it does run as expected. Symptom: 1. gst-launch-1.0 v4l2src io-mode=2 ! fakesink failed with following error message ERROR: from element /GstPipeline:pipeline0/GstV4l2Src:v4l2src0: Failed to configure internal buffer pool. (log file with GST_DEBUG=6 is attached(tmp2.log). below is just the essense of the error message) v4l2 gstv4l2bufferpool.c:557:gst_v4l2_buffer_pool_set_config:<v4l2src0:pool:src> can't allocate, setting maximum to minimum bufferpool gstbufferpool.c:551:default_set_config:<v4l2src0:pool:src> config GstBufferPoolConfig, caps=(GstCaps)"NULL", size=(uint)0, min-buffers=(uint)2, max-buffers=(uint)2, allocator=(GstAllocator)"NULL", params=(GstAllocationParams)NULL; v4l2 gstv4l2object.c:3196:gst_v4l2_object_decide_allocation:<v4l2src0> error: Failed to configure internal buffer pool. My findings: 1. gst-plaugins-good from master branch on official tree worked as expected. 2. Error happens because can_allocate is 0 as shown below. gst_v4l2_buffer_pool_set_config (GstBufferPool * bpool, GstStructure * config) .... case GST_V4L2_IO_MMAP: can_allocate = GST_V4L2_ALLOCATOR_CAN_ALLOCATE (pool->vallocator, MMAP); According to the current code, it seems to me that kernel needs to support not only VIDIOC_REQBUFS but also VIDIOC_CREATE_BUFS ioctl, in order to use v4l2allocator. 3. Do we need to set "flags" to the allocator like below so that GST_V4L2_ALLOCATOR_CAN_ALLOCATE () macro can work as expected ? Please ignore if this is in your expectation. Maybe I'm misunderstanding something.... gst_v4l2_allocator_create_buf (GstV4l2Allocator * allocator) @@ -610,10 +648,20 @@ gst_v4l2_allocator_new (GstObject * parent, gint video_fd, allocator->type = format->type; allocator->format = *format; flags |= GST_V4L2_ALLOCATOR_PROBE (allocator, MMAP); flags |= GST_V4L2_ALLOCATOR_PROBE (allocator, USERPTR); flags |= GST_V4L2_ALLOCATOR_PROBE (allocator, DMABUF); + GST_OBJECT_FLAG_SET (allocator, flags); if (flags == 0) goto not_supported; Question: 1. Is there any special reason why VIDIOC_CREATE_BUFS ioctl is needed ? According to the following document, it seems to me that VIDIOC_CREATE_BUFS is not mandatory one. <a class="moz-txt-link-freetext" href="http://linuxtv.org/downloads/v4l-dvb-apis/vidioc-create-bufs.html">http://linuxtv.org/downloads/v4l-dvb-apis/vidioc-create-bufs.html</a> Our kernel currently does only support VIDIOC_REQBUS, and doe not support VIDIOC_CREATE_BUFS. I'm not so familiar with the multimedia portion, so please forgive me if I'm asking silly question. Any insight would be highly appreciated. Looking forward to hearing from you. KInd Regards, Makoto Harada (2014/04/29 8:40), Makoto Harada wrote: </div> <blockquote cite="mid:535EE6DE.4090403@gmail.com" type="cite"> <meta content="text/html; charset=ISO-8859-1" http-equiv="Content-Type"> <div class="moz-cite-prefix">Thank you so much, Nicolas, for your kind reply. This is exactly what I needed. I'll try it. Kind Regards, Makoto (2014/04/27 2:23), Nicolas Dufresne wrote: </div> <blockquote cite="mid:1398533034.4135.23.camel@mpb-nicolas" type="cite"> <meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1"> <meta name="GENERATOR" content="GtkHTML/4.6.6"> Le samedi 26 avril 2014 à 13:22 -0400, Nicolas Dufresne a écrit : <blockquote type="CITE"> 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> [1] <a moz-do-not-send="true" href="http://cgit.collabora.com/git/user/nicolas/gst-plugins-good.git/log/?h=v4l2-allocator">http://cgit.collabora.com/git/user/nicolas/gst-plugins-good.git/log/?h=v4l2-allocator</a> <fieldset class="mimeAttachmentHeader"></fieldset> <pre wrap="">_______________________________________________ gstreamer-devel mailing list <a moz-do-not-send="true" class="moz-txt-link-abbreviated" href="mailto:gstreamer-devel@lists.freedesktop.org">gstreamer-devel@lists.freedesktop.org</a> <a moz-do-not-send="true" class="moz-txt-link-freetext" href="http://lists.freedesktop.org/mailman/listinfo/gstreamer-devel">http://lists.freedesktop.org/mailman/listinfo/gstreamer-devel</a> </pre> </blockquote> </blockquote> </body> </html>