<html><head><meta http-equiv="Content-Type" content="text/html; charset=gb2312"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; ">I'm not entirely sure I understand your description of the problem...<div> </div><div>but you wouldn't be able to re-use a GstBuffer (or what the 'data' member points to), until the last unref.  Perhaps if you are trying to re-use the same buffer while other parts of the pipeline still hold a ref to it, this would be causing problems.</div><div> </div><div>BR,</div><div>-R</div><div> </div><div> </div><div><div><div>On Jan 9, 2010, at 4:24 AM, Chen, Weian wrote:</div> <blockquote type="cite"> <o:smarttagtype namespaceuri="urn:schemas-microsoft-com:office:smarttags" name="PersonName">  <style>  </style> <div lang="ZH-CN" link="blue" vlink="blue" style="word-wrap: break-word;-webkit-nbsp-mode: space; -webkit-line-break: after-white-space"> <div class="Section1"><o:p> </o:p>Thanks a lot for your information/suggestion.<o:p></o:p><o:p> </o:p>And I have made some experiments, and found that: I have to create new GstBuffer for every gst_pad_push() in _chain(), once the GstBuffer is used, it could not push data to downstream element successfully, the pipeline still keeps running, but the data in GstBuffer can’t be written into file.<o:p></o:p><o:p> </o:p>Please note, I mean I need to create GstBuffer for each call of _chain(), but not the real buffer which will contain real data (GstBufer’s member variable ->data will point this buffer)<o:p></o:p><o:p> </o:p>What’s the problem?<o:p></o:p><o:p> </o:p> <div>thanks,<o:p></o:p>Weian<o:p></o:p> </div> <div> <div class="MsoNormal" align="center" style="text-align:center"> <hr size="2" width="100%" align="center" tabindex="-1"> </div>From: Clark, Rob [mailto:rob@ti.com] Sent: 2010年1月9日 17:55 To: Discussion of the development of GStreamer Subject: Re: [gst-devel] Question on how to use GstBuffer?<o:p></o:p> </div><o:p> </o:p>yes, there are a handful of examples of this..  look for example, in v4l2bufferpool..  xvimagesink, etc..<o:p></o:p> <div><o:p> </o:p> </div> <div>basically the principle is to subclass GstBuffer, provide your own finalize function that revives the buffer and returns it to your pool of buffers.<o:p></o:p> </div> <div><o:p> </o:p> </div> <div><o:p> </o:p> </div> <div>(random thought:  really, it's a pattern seen in enough gst elements, that perhaps it would be nice to see a generic GstBufferPool class..)<o:p></o:p> </div> <div><o:p> </o:p> </div> <div><o:p> </o:p> </div> <div>BR,<o:p></o:p> </div> <div>-R<o:p></o:p> </div> <div><o:p> </o:p> <div> <div> <div>On Jan 7, 2010, at 8:56 PM, <st1:personname w:st="on">Chen, Weian</st1:personname> wrote:<o:p></o:p> </div> <o:p></o:p> <span style="orphans: 2;widows: 2;-webkit-border-horizontal-spacing: 0px; -webkit-border-vertical-spacing: 0px;-webkit-text-decorations-in-effect: none; -webkit-text-size-adjust: auto;-webkit-text-stroke-width: 0px;word-spacing: 0px"> <div link="blue" vlink="purple"> <div>Hi All,<u1:p></u1:p><o:p></o:p><u1:p> </u1:p><o:p></o:p>In my current element, I will create and new a GstBuffer (which means to use g_malloc to allocate buffer) in the _chain() function for each frame.<u1:p></u1:p><o:p></o:p><u1:p> </u1:p><o:p></o:p>My question is: Can I allocate several buffers (ring buffers) ahead of time, then I can re-use them and don’t need to allocate buffer for each call of _chain, if yes, how?<u1:p></u1:p><o:p></o:p><u1:p> </u1:p><o:p></o:p>Thanks in advanced.<u1:p></u1:p><o:p></o:p><u1:p> </u1:p><o:p></o:p>Weian<u1:p></u1:p><o:p></o:p> </div>------------------------------------------------------------------------------ This <a href="http://SF.Net/">SF.Net</a> email is sponsored by the Verizon Developer Community Take advantage of Verizon's best-in-class app development support A streamlined, 14 day to market process makes app distribution fast and easy Join now and get one step closer to millions of Verizon customers <a href="http://p.sf.net/sfu/verizon-dev2dev">http://p.sf.net/sfu/verizon-dev2dev</a> _______________________________________________ gstreamer-devel mailing list <a href="mailto:gstreamer-devel@lists.sourceforge.net">gstreamer-devel@lists.sourceforge.net</a> <a href="https://lists.sourceforge.net/lists/listinfo/gstreamer-devel">https://lists.sourceforge.net/lists/listinfo/gstreamer-devel</a><o:p></o:p> </div> </div><o:p> </o:p> </div> </div> </div> </div> ------------------------------------------------------------------------------ This <a href="http://SF.Net">SF.Net</a> email is sponsored by the Verizon Developer Community Take advantage of Verizon's best-in-class app development support A streamlined, 14 day to market process makes app distribution fast and easy Join now and get one step closer to millions of Verizon customers <a href="http://p.sf.net/sfu/verizon-dev2dev">http://p.sf.net/sfu/verizon-dev2dev</a> _______________________________________________ gstreamer-devel mailing list <a href="mailto:gstreamer-devel@lists.sourceforge.net">gstreamer-devel@lists.sourceforge.net</a> <a href="https://lists.sourceforge.net/lists/listinfo/gstreamer-devel">https://lists.sourceforge.net/lists/listinfo/gstreamer-devel</a> </o:smarttagtype></blockquote></div> </div></body></html>