<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=blue vlink=purple><div class=WordSection1><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif'>Thanks again Nicolas. I feel like I’m getting very close. Here’s what I have right now, and this basically kinda sorta works:<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif'>tail -n 1000 -f /home/pi/test.txt | /opt/gst/bin/gst-launch-1.0 -v fdsrc ! subparse ! txt. videotestsrc is-live=true ! video/x-raw, width =800, height=480, framerate=10/1 ! videoconvert ! decodebin ! textoverlay name=txt ! omxh264enc target-bitrate=800000 control-rate=3 ! tcpserversink host=0.0.0.0 port=9000<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif'>I can inject items to test.txt from the shell like this:<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif'>printf "7\n00:01:59,826 --> 00:02:59,000\nNOW I SAY WORK\n\n" >> /home/pi/test.txt<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif'>Now my challenge is, how do I post the proper time ranges? Unfortunately it seems I can’t keep appending 00:00:00,000 --> 99:99:99,000 because it will only show one subtitle at a time and it seems to always be the first one for that time-range. So the second sub-title wouldn’t overwrite the first one (which is basically what I need).<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif'>So I think these are my options:<o:p></o:p></span></p><p class=MsoListParagraph style='text-indent:-.25in;mso-list:l0 level1 lfo1'><![if !supportLists]><span style='font-size:11.0pt;font-family:"Calibri",sans-serif'><span style='mso-list:Ignore'>-<span style='font:7.0pt "Times New Roman"'> </span></span></span><![endif]><span style='font-size:11.0pt;font-family:"Calibri",sans-serif'>Is there another format or something that the subtitles can be written in?<o:p></o:p></span></p><p class=MsoListParagraph style='text-indent:-.25in;mso-list:l0 level1 lfo1'><![if !supportLists]><span style='font-size:11.0pt;font-family:"Calibri",sans-serif'><span style='mso-list:Ignore'>-<span style='font:7.0pt "Times New Roman"'> </span></span></span><![endif]><span style='font-size:11.0pt;font-family:"Calibri",sans-serif'>Or a way to cause newer sub-titles take precedence over older ones?<o:p></o:p></span></p><p class=MsoListParagraph style='text-indent:-.25in;mso-list:l0 level1 lfo1'><![if !supportLists]><span style='font-size:11.0pt;font-family:"Calibri",sans-serif'><span style='mso-list:Ignore'>-<span style='font:7.0pt "Times New Roman"'> </span></span></span><![endif]><span style='font-size:11.0pt;font-family:"Calibri",sans-serif'>Or am I going to need to keep track of the play-time from my secondary process and regularly append accurate times to the file/stdout?<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif'>Thank you<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif'>-Adam<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif'><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><span style='font-size:11.0pt;font-family:"Calibri",sans-serif'>From:</span></b><span style='font-size:11.0pt;font-family:"Calibri",sans-serif'> gstreamer-devel [mailto:gstreamer-devel-bounces@lists.freedesktop.org] <b>On Behalf Of </b>Nicolas Dufresne<br><b>Sent:</b> Monday, February 27, 2017 7:34 AM<br><b>To:</b> Discussion of the development of and with GStreamer <gstreamer-devel@lists.freedesktop.org><br><b>Subject:</b> Re: Dynamic text-overlay on live-stream using gst-launch-1.0<o:p></o:p></span></p></div></div><p class=MsoNormal><o:p> </o:p></p><div><p class=MsoNormal>Le lundi 27 février 2017 à 07:05 -0800, Adam Plocher a écrit :<o:p></o:p></p></div><blockquote style='margin-top:5.0pt;margin-bottom:5.0pt'><div><p class=MsoNormal>Nicolas, thank you for your response. fdsrc seems like it would be a good solution, but I'm having issues getting it to work.<o:p></o:p></p><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal>It seems like I need to specify the caps after the fdsrc, otherwise it fails in other ways. e.g.<o:p></o:p></p></div><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal>Specifying text/x-raw:<o:p></o:p></p></div><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal>tail -f /home/pi/test.txt | /opt/gst/bin/gst-launch-1.0 fdsrc fd=0 ! "text/x-raw" ! txt. videotestsrc ! videoconvert ! decodebin ! textoverlay name=txt ! omxh264enc target-bitrate=800000 control-rate=3 ! tcpserversink host=0.0.0.0 port=9000<o:p></o:p></p></div></div></blockquote><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal>I think you forgot to keep subparse element.<o:p></o:p></p></div><div><p class=MsoNormal><o:p> </o:p></p></div><blockquote style='margin-top:5.0pt;margin-bottom:5.0pt'><div><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal>Results in:<o:p></o:p></p></div><div><p class=MsoNormal><o:p> </o:p></p></div><div><div><p class=MsoNormal>Pipeline is PREROLLING ...<o:p></o:p></p></div><div><p class=MsoNormal>ERROR: from element /GstPipeline:pipeline0/GstCapsFilter:capsfilter0: Filter caps do not completely specify the output format<o:p></o:p></p></div><div><p class=MsoNormal>Additional debug info:<o:p></o:p></p></div><div><p class=MsoNormal>gstcapsfilter.c(455): gst_capsfilter_prepare_buf (): /GstPipeline:pipeline0/GstCapsFilter:capsfilter0:<o:p></o:p></p></div><div><p class=MsoNormal>Output caps are unfixed: text/x-raw, format=(string){ pango-markup, utf8 }<o:p></o:p></p></div><div><p class=MsoNormal>ERROR: pipeline doesn't want to preroll.<o:p></o:p></p></div></div><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal>Specifying text/plain:<o:p></o:p></p></div><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal>tail -f /home/pi/test.txt | /opt/gst/bin/gst-launch-1.0 fdsrc fd=0 ! "text/plain" ! txt. videotestsrc ! videoconvert ! decodebin ! textoverlay name=txt ! omxh264enc target-bitrate=800000 control-rate=3 ! tcpserversink host=0.0.0.0 port=9000<o:p></o:p></p></div><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal>Results in:<o:p></o:p></p></div><div><p class=MsoNormal><o:p> </o:p></p></div><div><div><p class=MsoNormal>0:00:00.501757360 4549 0x1e085c0 ERROR GST_PIPELINE grammar.y:714:gst_parse_perform_link: could not link fdsrc0 to txt, txt can't handle caps text/plain<o:p></o:p></p></div><div><p class=MsoNormal>WARNING: erroneous pipeline: could not link fdsrc0 to txt, txt can't handle caps text/plain<o:p></o:p></p></div></div><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal>No caps at all:<o:p></o:p></p></div><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal>tail -f /home/pi/test.txt | /opt/gst/bin/gst-launch-1.0 fdsrc fd=0 ! txt. videotestsrc ! videoconvert ! decodebin ! textoverlay name=txt ! omxh264enc target-bitrate=800000 control-rate=3 ! tcpserversink host=0.0.0.0 port=9000<o:p></o:p></p></div><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal>Results in:<o:p></o:p></p></div><div><p class=MsoNormal><o:p> </o:p></p></div><div><div><p class=MsoNormal>Pipeline is PREROLLING ...<o:p></o:p></p></div><div><p class=MsoNormal>WARNING: from element /GstPipeline:pipeline0/GstTextOverlay:txt: Could not multiplex stream.<o:p></o:p></p></div><div><p class=MsoNormal>Additional debug info:<o:p></o:p></p></div><div><p class=MsoNormal>gstbasetextoverlay.c(2449): gst_base_text_overlay_video_event (): /GstPipeline:pipeline0/GstTextOverlay:txt:<o:p></o:p></p></div><div><p class=MsoNormal>received non-TIME newsegment event on video input<o:p></o:p></p></div><div><p class=MsoNormal>WARNING: from element /GstPipeline:pipeline0/GstDecodeBin:decodebin0: Delayed linking failed.<o:p></o:p></p></div><div><p class=MsoNormal>Additional debug info:<o:p></o:p></p></div><div><p class=MsoNormal>./grammar.y(510): gst_parse_no_more_pads (): /GstPipeline:pipeline0/GstDecodeBin:decodebin0:<o:p></o:p></p></div><div><p class=MsoNormal>failed delayed linking some pad of GstDecodeBin named decodebin0 to some pad of GstTextOverlay named txt<o:p></o:p></p></div><div><p class=MsoNormal>ERROR: from element /GstPipeline:pipeline0/GstVideoTestSrc:videotestsrc0: Internal data stream error.<o:p></o:p></p></div><div><p class=MsoNormal>Additional debug info:<o:p></o:p></p></div><div><p class=MsoNormal>gstbasesrc.c(2951): gst_base_src_loop (): /GstPipeline:pipeline0/GstVideoTestSrc:videotestsrc0:<o:p></o:p></p></div><div><p class=MsoNormal>streaming stopped, reason not-linked (-1)<o:p></o:p></p></div><div><p class=MsoNormal>ERROR: pipeline doesn't want to preroll.<o:p></o:p></p></div></div><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal>There is some information here (regarding the older version of gst-launch): <o:p></o:p></p></div><div><p class=MsoNormal><a href="http://gstreamer-devel.966125.n4.nabble.com/Dynamic-text-again-td3676141.html">http://gstreamer-devel.966125.n4.nabble.com/Dynamic-text-again-td3676141.html</a><o:p></o:p></p></div><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal>And that links to this bug that was resolved (again, old gst-launch): <o:p></o:p></p></div><div><p class=MsoNormal><a href="https://bugzilla.gnome.org/show_bug.cgi?id=654959">https://bugzilla.gnome.org/show_bug.cgi?id=654959</a><o:p></o:p></p></div><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal>I've seen a couple examples which used the "text/plain" caps.<o:p></o:p></p></div><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal>I'm certainly open to cracking open the Python lib and giving it a shot. I would need to read up on it a bit and I'm not familiar with the appsrc, either, but that's something else I'm open to. I have done very basic stuff with the Python libs but nothing too fancy or dynamic (basic pipelines, no more complex than I would get from gst-launch-1.0).<o:p></o:p></p></div><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal>What would you recommend? Is there an example or resource you could point me towards?<o:p></o:p></p></div><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal>Thank you for your help<o:p></o:p></p></div><div><p class=MsoNormal><o:p> </o:p></p></div></div><div><p class=MsoNormal><o:p> </o:p></p><div><p class=MsoNormal>On Sun, Feb 26, 2017 at 2:46 PM, Nicolas Dufresne <<a href="mailto:nicolas@ndufresne.ca" target="_blank">nicolas@ndufresne.ca</a>> wrote:<br><br><o:p></o:p></p><blockquote style='margin-top:5.0pt;margin-bottom:5.0pt'><p class=MsoNormal style='margin-bottom:12.0pt'>Le dimanche 26 février 2017 à 06:18 -0800, Adam Plocher a écrit :<br>> Hello, I apologize if I'm posting this in the wrong place. I've<br>> previously asked this on stackoverflow and never got a response: http<br>> ://<a href="http://stackoverflow.com/questions/42128804/polling-a-text-file-and-" target="_blank">stackoverflow.com/questions/42128804/polling-a-text-file-and-</a><br>> overlaying-the-result-in-gstreamer<br>><br>> I have a Raspberry Pi with a camera and I'm live streaming that back<br>> to another unit (it's for a baby monitor). On the same Pi, I have a<br>> temperature sensor that is dumping the current temp to a file every 5<br>> seconds.<br>><br>> My question: Is it possible to somehow poll that txt file and update<br>> a text-overlay on the live stream based on the current contents of<br>> that file?<br><br>filsesrc does not have this feature unfortunatly. I believe using<br>fdsrc, you could:<br><br> tail -f text.txt | gst-launch-1.0 fdsrc ! ...<br><br>Let me know if that is a good work-around. If you are writing an app,<br>this can be done with a pipe, or if you prefer, with appsrc.<br><br>><br>> I've tried using a filesrc and subparse, and it will grab it<br>> initially if I format the input text file properly, but it doesn't<br>> seem to update itself:<br>><br>> gst-launch-1.0 -v \<br>> filesrc location=/home/pi/temp.txt ! subparse ! txt. rpicamsrc<br>> awb-mode=0 awb-gain-red=1 awb-gain-blue=2 rotation=0 bitrate=820000<br>> preview=false brightness=67 contrast=30 sharpness=40 \<br>> ! video/x-h264,width=800,height=480,framerate=10/1 \<br>> ! h264parse ! decodebin ! videoconvert ! clockoverlay shaded-<br>> background=true draw-shadow=true font-desc="Nimbus Mono" \<br>> ! textoverlay name=txt shaded-background=yes \<br>> ! omxh264enc control-rate=3 target-bitrate=850000 \<br>> ! tcpserversink host=0.0.0.0 port=5555 sync=true<br>><br>> The input file looks like this:<br>> 1<br>> 00:00:00,000 --> 99:59:59,000<br>> 69 degrees<br>> Thank you!<br>> _______________________________________________<br>> gstreamer-devel mailing list<br>> <a href="mailto:gstreamer-devel@lists.freedesktop.org">gstreamer-devel@lists.freedesktop.org</a><br>> <a href="https://lists.freedesktop.org/mailman/listinfo/gstreamer-devel" target="_blank">https://lists.freedesktop.org/mailman/listinfo/gstreamer-devel</a><br>_______________________________________________<br>gstreamer-devel mailing list<br><a href="mailto:gstreamer-devel@lists.freedesktop.org">gstreamer-devel@lists.freedesktop.org</a><br><a href="https://lists.freedesktop.org/mailman/listinfo/gstreamer-devel" target="_blank">https://lists.freedesktop.org/mailman/listinfo/gstreamer-devel</a><o:p></o:p></p></blockquote></div><p class=MsoNormal><o:p> </o:p></p></div><pre>_______________________________________________<o:p></o:p></pre><pre>gstreamer-devel mailing list<o:p></o:p></pre><pre><a href="mailto:gstreamer-devel@lists.freedesktop.org">gstreamer-devel@lists.freedesktop.org</a><o:p></o:p></pre><pre><a href="https://lists.freedesktop.org/mailman/listinfo/gstreamer-devel">https://lists.freedesktop.org/mailman/listinfo/gstreamer-devel</a><o:p></o:p></pre></blockquote></div></body></html>