Hello, I am trying to get a good DVB stream with gst-launch-1.0 by means of mpegtsmux. I achieved to generate and send a stream over UDP. I can open and watch it with VLC in the receiver, however, if I analyze the TS with an analyzer, it gives me errors all the time (see the attached screenshot). According to the errors, I think that the problem is in the adaptation field, but I do not know what is happening. Any clue? This is the pipeline that I am using, is there anything wrong in it? gst-launch-1.0 -v videotestsrc do-timestamp=true is-live=true ! x264enc ! queue ! h264parse ! mpegtsmux ! udpsink host=10.192.33.136 port=2400 sync=1 Thank you very much in advance. Best regards, Antonio. _______________________________________________ gstreamer-devel mailing list [hidden email] https://lists.freedesktop.org/mailman/listinfo/gstreamer-devel screenshot.jpg (66K) Download Attachment |
Hello again, Well, I have been doing some tests. I tried to save the TS in a file and fed it to ffprobe, which said that the timestamps are incorrect (PTS < DTS, what has no sense): [mpegts @ 0x3854120] Invalid timestamps stream=0, pts=324002999, dts=324008999, size=4040 [mpegts @ 0x3854120] Invalid timestamps stream=0, pts=324009000, dts=324011999, size=4042 [mpegts @ 0x3854120] Invalid timestamps stream=0, pts=324014999, dts=324020999, size=3925 [mpegts @ 0x3854120] Invalid timestamps stream=0, pts=324020999, dts=324023999, size=4048 [mpegts @ 0x3854120] Invalid timestamps stream=0, pts=324027000, dts=324032999, size=4050 [mpegts @ 0x3854120] Invalid timestamps stream=0, pts=324032999, dts=324035999, size=3886 [mpegts @ 0x3854120] Invalid timestamps stream=0, pts=324038999, dts=324044999, size=4019 [mpegts @ 0x3854120] Invalid timestamps stream=0, pts=324045000, dts=324047999, size=3891 [mpegts @ 0x3854120] Invalid timestamps stream=0, pts=324050999, dts=324056999, size=3927 [mpegts @ 0x3854120] Invalid timestamps stream=0, pts=324056999, dts=324059999, size=3865 [mpegts @ 0x3854120] Invalid timestamps stream=0, pts=324063000, dts=324068999, size=3910 Then I tried to save the raw H.264 video, removing the muxer from pipeline and fed that file to ffprobe and, this time, it does not say anything about timestamps. So, I guess that the mpegtsmux is restamping the stream and it is doing it in a wrong way. Do you think this is possible? Is there any known bug about this? Best regards, Antonio. 2017-08-29 12:06 GMT+02:00 Antonio Jesús Díaz Honrubia <[hidden email]>:
_______________________________________________ gstreamer-devel mailing list [hidden email] https://lists.freedesktop.org/mailman/listinfo/gstreamer-devel |
Not sure what is going wrong in mpegtsmux, but an h264 bitstream does not
contain any timing information in itself (except for some time-base info). It is the container (in this case MPEG2TS) that adds such information. To debug the problem, you could start with tuning the encoder to use zero-latency mode, set profile to main and disable b-frames and see if the problem persists. -- Sent from: http://gstreamer-devel.966125.n4.nabble.com/ _______________________________________________ gstreamer-devel mailing list [hidden email] https://lists.freedesktop.org/mailman/listinfo/gstreamer-devel |
Thank you very much for the info and the hep. In fact, those were the next steps that I did. The zero-latency had no effect since the same error was present, then I tried to set b-frames to 0, which solved the problem of the differences, so it seems that the muxer does not work properly with B frames. Anyway, I tried to analyze the resulting TS and the same errors (those shown in the screenshot attached to my first message) are still present in the analyzer. Best regards, Antonio. 2017-08-30 12:45 GMT+02:00 Arjen Veenhuizen <[hidden email]>: Not sure what is going wrong in mpegtsmux, but an h264 bitstream does not _______________________________________________ gstreamer-devel mailing list [hidden email] https://lists.freedesktop.org/mailman/listinfo/gstreamer-devel |
On Wed, 2017-08-30 at 13:02 +0200, Antonio Jesús Díaz Honrubia wrote: Hi Antonio, Out of curiosity - what version of GStreamer/mpegtsmux are you testing with? Cheers -Tim -- Tim Müller, Centricular Ltd - http://www.centricular.com Join us at the GStreamer Conference! 21-22 October 2017 in Prague, Czech Republic
_______________________________________________ gstreamer-devel mailing list [hidden email] https://lists.freedesktop.org/mailman/listinfo/gstreamer-devel |
Hello, GStreamer and mpegtsmux versions are 1.4.4. Best regards, Antonio. 2017-08-30 13:22 GMT+02:00 Tim Müller <[hidden email]>:
_______________________________________________ gstreamer-devel mailing list [hidden email] https://lists.freedesktop.org/mailman/listinfo/gstreamer-devel |
Hi, The support for DTS != PTS was improved in 1.8, so I advise you to try with a newer version, preferably 1.12 as there were more little fixes around this and I'm not exactly when they were added. Olivier On Wed, 2017-08-30 at 13:33 +0200, Antonio Jesús Díaz Honrubia wrote:
--Olivier Crête [hidden email] _______________________________________________ gstreamer-devel mailing list [hidden email] https://lists.freedesktop.org/mailman/listinfo/gstreamer-devel |
Free forum by Nabble | Edit this page |