<html xmlns:v="urn:schemas-microsoft-com:vml" xmlns:o="urn:schemas-microsoft-com:office:office" xmlns:w="urn:schemas-microsoft-com:office:word" xmlns:m="http://schemas.microsoft.com/office/2004/12/omml" xmlns="http://www.w3.org/TR/REC-html40"> <head> <meta http-equiv="Content-Type" content="text/html; charset=utf-8"> <meta name="Generator" content="Microsoft Word 15 (filtered medium)"> <style></style> </head> <body lang="EN-US" link="#0563C1" vlink="#954F72"> <div class="WordSection1"> <p class="MsoNormal" style="margin-bottom:8.0pt;line-height:106%">Nicolas, <o:p></o:p></p> <p class="MsoNormal" style="margin-bottom:8.0pt;line-height:106%">Thank you for your reply.<o:p></o:p></p> <p class="MsoNormal" style="margin-bottom:8.0pt;line-height:106%">I am using the following pipeline [in C code] to display streaming text. In a separate thread, I push text buffers once every second to appsrc using gst_app_src_push_buffer. I use gst_buffer_new_allocate to create the text buffers and gst_buffer_fill to set the actual text to be displayed. I correctly set the buffer timestamps and the buffer durations are set to 1 second.<o:p></o:p></p> <p class="MsoNormalCxSpMiddle" style="margin-bottom:8.0pt;mso-add-space:auto;line-height:106%"> <o:p> </o:p></p> <p class="MsoNormalCxSpMiddle" style="mso-margin-top-alt:0in;margin-right:0in;margin-bottom:8.0pt;margin-left:.5in;mso-add-space:auto;line-height:106%"> appsrc caps="text/x-raw" ! capsfilter caps="text/x-raw,format=utf8" ! txt. <o:p></o:p></p> <p class="MsoNormalCxSpMiddle" style="mso-margin-top-alt:0in;margin-right:0in;margin-bottom:8.0pt;margin-left:.5in;mso-add-space:auto;line-height:106%"> videotestsrc pattern=white ! <o:p></o:p></p> <p class="MsoNormalCxSpMiddle" style="mso-margin-top-alt:0in;margin-right:0in;margin-bottom:8.0pt;margin-left:.5in;mso-add-space:auto;line-height:106%"> textoverlay name=txt ! autovideosink <o:p></o:p></p> <p class="MsoNormalCxSpMiddle" style="mso-margin-top-alt:0in;margin-right:0in;margin-bottom:8.0pt;margin-left:.5in;mso-add-space:auto;line-height:106%"> <o:p> </o:p></p> <p class="MsoNormalCxSpMiddle" style="margin-bottom:8.0pt;mso-add-space:auto;line-height:106%"> <o:p> </o:p></p> <p class="MsoNormal" style="margin-bottom:8.0pt;line-height:106%">This pipeline runs just fine and the streaming text updates are 1 second apart just like I want them to be. <o:p></o:p></p> <p class="MsoNormal" style="margin-bottom:8.0pt;line-height:106%">However, there is a memory leak somewhere – not good! I have confirmed that when I stop pushing buffers to appsrc, the memory leaks also stop. <o:p></o:p></p> <p class="MsoNormal" style="margin-bottom:8.0pt;line-height:106%">According to the appsrc documentation, the gst_app_src_push_buffer function takes ownership of the buffer so I’m not doing unref after I push the buffer. It appears that the textoverlay element is not releasing the text buffers after it displays the text. I ran one test for over an hour and the memory just kept slowly growing. When I stop the pipeline I see the memory being put back. <o:p></o:p></p> <p class="MsoNormal" style="margin-bottom:8.0pt;line-height:106%">I tried setting GST_DEBUG="GST_TRACER:7" and GST_TRACERS="leaks(GstBuffer)" and running my test app in a command window but the tracing didn’t seem to work. I got no trace output. My test thread has gst_init at the beginning and gst_deinit at the end. My development machine is windows 7 and I’m using GStreamer 1.10.4 with your windows pre-built binaries. <o:p></o:p></p> <p class="MsoNormalCxSpMiddle" style="margin-bottom:8.0pt;mso-add-space:auto;line-height:106%"> Any help would be much appreciated. <o:p></o:p></p> <p class="MsoNormal" style="margin-bottom:8.0pt;line-height:106%">Bill <o:p></o:p></p> <p class="MsoNormal"><span style="color:#1F497D"><o:p> </o:p></span></p> <div> <div style="border:none;border-top:solid #E1E1E1 1.0pt;padding:3.0pt 0in 0in 0in"> <p class="MsoNormal"><b>From:</b> gstreamer-devel [mailto:gstreamer-devel-bounces@lists.freedesktop.org] <b>On Behalf Of </b>Nicolas Dufresne<br> <b>Sent:</b> Friday, June 09, 2017 1:59 PM<br> <b>To:</b> Discussion of the development of and with GStreamer <gstreamer-devel@lists.freedesktop.org><br> <b>Subject:</b> Re: Textoverlay questions<o:p></o:p></p> </div> </div> <p class="MsoNormal"><o:p> </o:p></p> <div> <p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Times New Roman",serif">Le vendredi 09 juin 2017 à 15:35 +0000, William Salibrici a écrit :<o:p></o:p></span></p> </div> <blockquote style="margin-top:5.0pt;margin-bottom:5.0pt"> <p class="MsoNormal" style="margin-bottom:8.0pt;line-height:105%">I am using the following simple pipeline segment to add a text area under my compositor video output. In a separate thread, I set the “text” property once every second to update the rendered text. For my application, the text updates must be real-time. <o:p></o:p></p> <p class="MsoNormalCxSpMiddle" style="margin-bottom:8.0pt;mso-add-space:auto;line-height:105%"> <o:p> </o:p></p> <p class="MsoNormalCxSpMiddle" style="mso-margin-top-alt:0in;margin-right:0in;margin-bottom:8.0pt;margin-left:.5in;mso-add-space:auto;line-height:105%"> videotestsrc pattern=white ! textoverlay ! queue ! comp.sink_2 <o:p></o:p></p> <p class="MsoNormalCxSpMiddle" style="margin-bottom:8.0pt;mso-add-space:auto;line-height:105%"> <o:p> </o:p></p> <p class="MsoNormal" style="margin-bottom:8.0pt;line-height:105%">My development machine is windows 7 and I’m using GStreamer 1.10.4 with your windows pre-built binaries. <o:p></o:p></p> <p class="MsoNormal" style="margin-bottom:8.0pt;line-height:105%">My overall pipeline runs without errors but the text updates are not always 1 second apart. Sometimes there are pauses between updates greater than 1 second. Other times updates come back to back with no discernable delay. Sometimes updates appear to be skipped altogether [maybe they are just flying by too fast for me to see them]. The latency for displaying text seems to vary quite a bit. <o:p></o:p></p> <p class="MsoNormal" style="margin-bottom:8.0pt;line-height:105%">So, here are some questions:<o:p></o:p></p> <ol style="margin-top:0in" start="1" type="1"> <li class="MsoNormalCxSpMiddle" style="margin-bottom:8.0pt;mso-add-space:auto;line-height:105%;mso-list:l0 level1 lfo3"> What is the latency for displaying text [the time between when the g_object_set function is called to set the text to be displayed and when the text will actually be displayed]? <o:p></o:p></li><li class="MsoNormalCxSpMiddle" style="margin-bottom:8.0pt;mso-add-space:auto;line-height:105%;mso-list:l0 level1 lfo3"> Is there any way to achieve a relatively constant latency for displaying text? <o:p> </o:p></li><li class="MsoNormalCxSpMiddle" style="margin-bottom:8.0pt;mso-add-space:auto;line-height:105%;mso-list:l0 level1 lfo3"> Is there any way force the text to be synchronized with the other input video streams to my compositor? <o:p></o:p></li></ol> </blockquote> <div> <p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Times New Roman",serif"><o:p> </o:p></span></p> </div> <div> <p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Times New Roman",serif">textoverlay has a text pad. You can use this pad to stream text with timestamp on it. The simply way it to connect "filesrc location=file.srt ! subparse ! ..." Subpase supports most common text based sub-title formats, letting you set a timestamp and a duration for each text. You can of course replace filesrc with an appsrc or fdsrc to stream the data.<o:p></o:p></span></p> </div> <div> <p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Times New Roman",serif"><o:p> </o:p></span></p> </div> <div> <p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Times New Roman",serif">Nicolas<o:p></o:p></span></p> </div> </div> </body> </html>