<div dir="ltr">So basically one would never have two elements that are the same, and only differ in the name you made/created them with? </div> <div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Thu, May 16, 2019 at 7:19 AM Nicolas Dufresne <<a href="mailto:nicolas@ndufresne.ca">nicolas@ndufresne.ca</a>> wrote: </div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><div dir="auto"><div> <div class="gmail_quote"><div dir="ltr" class="gmail_attr">Le mer. 15 mai 2019 23 h 25, R C <<a href="mailto:cjvijf@gmail.com" target="_blank">cjvijf@gmail.com</a>> a écrit : </div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"> <div bgcolor="#FFFFFF"> <tt>so while messing with it, I forgot to change teh second part, and even though it seems incosistent, can someone explain why this works? (I am just putting the declarations here, rewritting to ugly got's into something nicr is not the problem)</tt> <tt> </tt> <tt>in the main part the declarations I had are:</tt> <tt>// Create the elements data.source = gst_element_factory_make("uridecodebin", "source"); data.audioconvert = gst_element_factory_make("audioconvert", "audioconvert"); data.audiosink = gst_element_factory_make("autoaudiosink", "audiosink"); data.videoconvert = gst_element_factory_make("videoconvert", "videoconvert"); data.videosink = gst_element_factory_make("autovideosink", "videosink");</tt> <tt> </tt> <tt>and I forgot to make the changes in the second part (pad_added_handler), surprised it worked, and seems counter-intuitive?</tt> <tt>GstPad *audiosink_pad = gst_element_get_static_pad(data->audioconvert, "sink"); GstPad *videosink_pad = gst_element_get_static_pad(data->videoconvert, "sink"); </tt></div></blockquote></div></div><div dir="auto">The names in the first part are the element names, while in this callback, you are handling pad names. Pad names are chosen by the elements and follow the pattern in the pad template (see gst-inspect-1.0 element to see the template).</div><div dir="auto"> </div><div dir="auto"> </div><div dir="auto"><div class="gmail_quote"><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><div bgcolor="#FFFFFF"><tt> </tt> <tt> </tt> <tt>but .. why?? How can it even find the right GstElement, since none of the are named "sink"? </tt> <tt> </tt> <tt>docs:</tt> <tt>****************************************************************** </tt> <h3>gst_element_get_static_pad ()</h3> <pre class="gmail-m_-70094805929649237m_-8735804386836938389programlisting"><a class="gmail-m_-70094805929649237m_-8735804386836938389link" href="https://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/GstPad.html" title="GstPad" rel="noreferrer" target="_blank">GstPad</a> * gst_element_get_static_pad (<code><a class="gmail-m_-70094805929649237m_-8735804386836938389link" href="https://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/GstElement.html" title="GstElement" rel="noreferrer" target="_blank">GstElement</a> *element</code>, <code>const <a href="https://gstreamer.freedesktop.org/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gchar" rel="noreferrer" target="_blank">gchar</a> *name</code>);</pre> Retrieves a pad from <code>element</code> by name. This version only retrieves already-existing (i.e. 'static') pads. Parameters element a <a class="gmail-m_-70094805929649237m_-8735804386836938389link" href="https://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/GstElement.html" title="GstElement" rel="noreferrer" target="_blank">GstElement</a> to find a static pad of. name the name of the static <a class="gmail-m_-70094805929649237m_-8735804386836938389link" href="https://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/GstPad.html" title="GstPad" rel="noreferrer" target="_blank">GstPad</a> to retrieve. <h4>Returns</h4> the requested <a class="gmail-m_-70094805929649237m_-8735804386836938389link" href="https://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/GstPad.html" title="GstPad" rel="noreferrer" target="_blank">GstPad</a> if found, otherwise <a href="https://gstreamer.freedesktop.org/usr/share/gtk-doc/html/glib/glib-Standard-Macros.html#NULL:CAPS" rel="noreferrer" target="_blank"><code class="gmail-m_-70094805929649237m_-8735804386836938389literal">NULL</code></a>. unref after usage. MT safe. ************************************************************************ <tt>thanks,</tt> <tt> </tt> <tt>Ron </tt> <tt> </tt> <tt></tt> <div class="gmail-m_-70094805929649237m_-8735804386836938389moz-cite-prefix">On 5/15/19 8:33 PM, R C wrote: </div> <blockquote type="cite"> <tt>Hello,</tt> <tt>I am trying to get a little more familiar with gstreamer, and thought I'd do some</tt> <tt>of the "basic" programming tutorial examples.</tt> <tt> </tt> <tt>I </tt>did play with the 3rd example: <a class="gmail-m_-70094805929649237m_-8735804386836938389moz-txt-link-freetext" href="https://gstreamer.freedesktop.org/documentation/tutorials/basic/dynamic-pipelines.html?gi-language=c" rel="noreferrer" target="_blank">https://gstreamer.freedesktop.org/documentation/tutorials/basic/dynamic-pipelines.html?gi-language=c</a> If I copy the example, and compile it, it works, no surprise there. But when I change it and do the "exercise", I get some weirdness. What I noticed is (well I probably missed something)... but the function call: <pre class="gmail-m_-70094805929649237m_-8735804386836938389language-c"><code class="gmail-m_-70094805929649237m_-8735804386836938389language-c">data.sink = gst_element_factory_make ("autoaudiosink", "sink"); According to the docs, the 2nd parameter can be 'whatever' you want to name it. Since I wanted to do the video part too, I figure I should change the name to "audio-something", and changed the second function call to: </code><code class="gmail-m_-70094805929649237m_-8735804386836938389language-c"> data.convert = gst_element_factory_make ("audioconvert", "convert"); (original) data.sink = gst_element_factory_make ("autoaudiosink", "audiosink"); (changed name)</code> of course in the even handler (pad_added_handler), the name needs to be changed in to: <code class="gmail-m_-70094805929649237m_-8735804386836938389language-c">GstPad *sink_pad = gst_element_get_static_pad (data->convert, "audiosink"); Browsing through the code, that should be it, BUT it seems "</code><code class="gmail-m_-70094805929649237m_-8735804386836938389language-c">sink_pad</code>"<code class="gmail-m_-70094805929649237m_-8735804386836938389language-c"></code><code class="gmail-m_-70094805929649237m_-8735804386836938389language-c"></code> always is NULL and the pipeline elements don't/can't be linked. (see errors below) since this is supposed to be a simple example, what am I missing? thanks, Ron errors: # ./basic-tutorial-3 Pipeline state changed from NULL to READY: Received new pad 'src_0' from 'source': (basic-tutorial-3:14679): GStreamer-CRITICAL **: 20:22:54.991: gst_pad_is_linked: assertion 'GST_IS_PAD (pad)' failed It has type 'video/x-raw' which is not raw audio. Ignoring. (basic-tutorial-3:14679): GStreamer-CRITICAL **: 20:22:54.992: gst_object_unref: assertion 'object != NULL' failed Received new pad 'src_1' from 'source': (basic-tutorial-3:14679): GStreamer-CRITICAL **: 20:22:54.992: gst_pad_is_linked: assertion 'GST_IS_PAD (pad)' failed (basic-tutorial-3:14679): GStreamer-CRITICAL **: 20:22:54.992: gst_pad_link_full: assertion 'GST_IS_PAD (sinkpad)' failed Type is 'audio/x-raw' but link failed. (basic-tutorial-3:14679): GStreamer-CRITICAL **: 20:22:54.992: gst_object_unref: assertion 'object != NULL' failed Error received from element source: Internal data stream error. Debugging information: gstbasesrc.c(2950): gst_base_src_loop (): /GstPipeline:test-pipeline/GstURIDecodeBin:source/GstSoupHTTPSrc:source: streaming stopped, reason not-linked (-1) </pre> </blockquote> </div> _______________________________________________ gstreamer-devel mailing list <a href="mailto:gstreamer-devel@lists.freedesktop.org" rel="noreferrer" target="_blank">gstreamer-devel@lists.freedesktop.org</a> <a href="https://lists.freedesktop.org/mailman/listinfo/gstreamer-devel" rel="noreferrer noreferrer" target="_blank">https://lists.freedesktop.org/mailman/listinfo/gstreamer-devel</a></blockquote></div></div></div> _______________________________________________ gstreamer-devel mailing list <a href="mailto:gstreamer-devel@lists.freedesktop.org" target="_blank">gstreamer-devel@lists.freedesktop.org</a> <a href="https://lists.freedesktop.org/mailman/listinfo/gstreamer-devel" rel="noreferrer" target="_blank">https://lists.freedesktop.org/mailman/listinfo/gstreamer-devel</a></blockquote></div>