<html> <head> <meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1"> <style type="text/css" style="display:none"></style> </head> <body dir="ltr" style="font-size:12pt;color:#000000;background-color:#FFFFFF;font-family:Calibri,Arial,Helvetica,sans-serif;"> <p>Hi Matt<br> </p> <p><br> </p> <p>Yes thanks for that, it seems to work fine. I actually used <strong>gst_util_set_value_from_string()</strong> which is a close relative.<br> </p> <p><br> </p> <p>I am having trouble checking whether the converted value is within bounds though, <span style="font-family: Calibri, Arial, Helvetica, sans-serif; font-size: 16px; background-color: rgb(255, 255, 255);"> <strong>g_param_value_validate</strong></span><strong>()</strong> always seems to return FALSE. I can live without checking for the moment, but if anyone spots anything obvious, let me know:<br> </p> <p><span style="font-size: 12pt; white-space: pre;"><br> </span></p> <p><span style="font-size: 12pt; white-space: pre;"></span><span style="font-size: 12pt;">GValue prop_value = G_VALUE_INIT;</span><br> </p> <div> <div><span style="white-space:pre"></span>GParamSpec *realParamSpec;<br> </div> <div><br> </div> <span style="white-space:pre"></span>realParamSpec = g_object_class_find_property(G_OBJECT_GET_CLASS("x264enc), "bitrate");</div> <div><span style="white-space:pre"></span>if (realParamSpec) {<br> </div> <div> <div> <div><span style="white-space:pre"></span>g_value_init(&prop_value, G_PARAM_SPEC_VALUE_TYPE(realParamSpec));<br> </div> <div><br> </div> <span style="white-space:pre"></span>gst_util_set_value_from_string(&prop_value, "500");</div> <div><br> </div> <div><span style="white-space:pre"></span>if (g_param_value_validate(realParamSpec, &prop_value)) {</div> <div> // this is good<br> } else {<br> </div> <div> // not within bounds<br> </div> <div> }<br> </div> <div> } else // property doesn't exist<br> </div> <div><br> </div> </div> <p><br> </p> <div style="color: rgb(33, 33, 33);"> <hr tabindex="-1" style="display:inline-block; width:98%"> <div id="divRplyFwdMsg" dir="ltr"><font face="Calibri, sans-serif" color="#000000" style="font-size:11pt"><b>From:</b> Matthew Waters <ystreet00@gmail.com><br> <b>Sent:</b> 23 July 2020 11:04<br> <b>To:</b> Discussion of the development of and with GStreamer; Gary Metalle<br> <b>Subject:</b> Re: set property value from a string</font> <div> </div> </div> <div> <div class="moz-cite-prefix">gst_parse_launch() uses gst_util_set_object_arg(): <a href="https://gstreamer.freedesktop.org/documentation/gstreamer/gstutils.html?gi-language=c#gst_util_set_object_arg"> https://gstreamer.freedesktop.org/documentation/gstreamer/gstutils.html?gi-language=c#gst_util_set_object_arg</a><br> <br> On 23/7/20 8:00 pm, Gary Metalle wrote:<br> </div> <blockquote type="cite"><style type="text/css" style="">  </style> <p>Is there a way to set a property value from a given string, i.e convert from G_STRING to whatever type is required for that property?<br> </p> <p><br> </p> <p>I have a string such as the following:<br> </p> <p><br> </p> <p>"byte-stream=TRUE rc-lookahead=0 tune=zerolatency speed-preset=ultrafast sync-lookahead=0"<br> </p> <p><br> </p> <p>That I split up into name/value pairs and then need to set each property.<br> </p> <p><br> </p> <p>I first use g_object_class_find_property() to find out if the named property exists and this is ok and it returns a GParamSpec which tells me the type of the property.<br> </p> <p><br> </p> <p>I've tried using g_value_transform() but this only seems to be able to cope with simple stuff like converting a double to an int etc. Is there no simple way to convert say a string of "TRUE" to a gboolean?<br> </p> <p>I have also tried g_param_convert() but didn't get anywhere with that either.<br> </p> <p><br> </p> <p>Someone must be doing it somehow because if you pass a pipeline string to gst_parse_launch() then it has to cope with this. It would be easy to custom write something for "TRUE"/"FALSE" to gboolean but not so for the enum types and the x264enc plugin has quite a few of those.<br> </p> <p><br> </p> <p>On a positive note I think g_param_value_validate() works when you want to check that a given value is within the range for the defined property, but it implies you've converted it to the correct type first.<br> </p> <br> <fieldset class="mimeAttachmentHeader"></fieldset> <pre class="moz-quote-pre">_______________________________________________ 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> <br> </div> </div> </body> </html>