<html> <head> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> </head> <body text="#000000" bgcolor="#FFFFFF"> <div class="moz-cite-prefix">On 16/5/19 1:11 pm, R C wrote: </div> <blockquote type="cite" cite="mid:8e654d6d-7dfd-9845-5ab5-d12c53e4f420@gmail.com"> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> <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> </blockquote> "sink" is the name of the pad on the element you're retrieving from (audio/videoconvert in this case) not the name of the element. <blockquote type="cite" cite="mid:8e654d6d-7dfd-9845-5ab5-d12c53e4f420@gmail.com"> <tt> </tt> <tt>but .. why?? How can it even find the right GstElement, since none of the are named "sink"? </tt> </blockquote> The element is the 'data->audio/videoconvert' parameters you pass into 'gst_element_get_static_pad'. Cheers -Matt <blockquote type="cite" cite="mid:8e654d6d-7dfd-9845-5ab5-d12c53e4f420@gmail.com"> <tt>docs:</tt> <tt>****************************************************************** </tt> <h3>gst_element_get_static_pad ()</h3> <pre class="programlisting"><a class="link" href="https://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/GstPad.html" title="GstPad" moz-do-not-send="true">GstPad</a> * gst_element_get_static_pad (<code><a class="link" href="https://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/GstElement.html" title="GstElement" moz-do-not-send="true">GstElement</a> *element</code>, <code>const <a href="https://gstreamer.freedesktop.org/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gchar" moz-do-not-send="true">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="link" href="https://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/GstElement.html" title="GstElement" moz-do-not-send="true">GstElement</a> to find a static pad of. name the name of the static <a class="link" href="https://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/GstPad.html" title="GstPad" moz-do-not-send="true">GstPad</a> to retrieve. <h4>Returns</h4> the requested <a class="link" href="https://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/GstPad.html" title="GstPad" moz-do-not-send="true">GstPad</a> if found, otherwise <a href="https://gstreamer.freedesktop.org/usr/share/gtk-doc/html/glib/glib-Standard-Macros.html#NULL:CAPS" moz-do-not-send="true"><code class="literal">NULL</code></a>. unref after usage. MT safe. ************************************************************************ <tt>thanks,</tt> <tt> </tt> <tt>Ron </tt> <tt> </tt> <div class="moz-cite-prefix">On 5/15/19 8:33 PM, R C wrote: </div> <blockquote type="cite" cite="mid:9a76bcb8-5103-7b6f-c11b-7d4007afd511@gmail.com"> <meta http-equiv="content-type" content="text/html; charset=UTF-8"> <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="moz-txt-link-freetext" href="https://gstreamer.freedesktop.org/documentation/tutorials/basic/dynamic-pipelines.html?gi-language=c" moz-do-not-send="true">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=" language-c"><code class=" language-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=" language-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=" language-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=" language-c">sink_pad</code>"<code class=" language-c"></code><code class=" language-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> <fieldset class="mimeAttachmentHeader"></fieldset> <pre class="moz-quote-pre" wrap="">_______________________________________________ gstreamer-devel mailing list <a class="moz-txt-link-abbreviated" href="mailto:gstreamer-devel@lists.freedesktop.org">gstreamer-devel@lists.freedesktop.org</a> <a class="moz-txt-link-freetext" href="https://lists.freedesktop.org/mailman/listinfo/gstreamer-devel">https://lists.freedesktop.org/mailman/listinfo/gstreamer-devel</a></pre> </blockquote> </body> </html>