retransmission with rtpbin and rtprtxqueue

Mon Jun 22 18:47:01 UTC 2020

Le lundi 22 juin 2020 à 10:09 -0500, andis a écrit :
> Hi, 
> 
> I want to live stream a video over mobile networks. To achieve minimal
> latency I need to use udp. To get started using the rtpbin with its
> retransmission mechanism, I am testing on the localhost with simulated paket
> loss. Here are my two pipelines: 
> 
> SENDER: 
> gst-launch-1.0 -v rtpbin name=rtpbin \
> souphttpsrc
> location=
> https://www.freedesktop.org/software/gstreamer-sdk/data/media/sintel_trailer-480p.webm
> ! matroskademux ! vp8dec ! x264enc bitrate=5000 ! rtph264pay ! rtprtxqueue !
> rtpbin.send_rtp_sink_0 \
> rtpbin.send_rtp_src_0 ! identity drop-probability=0.01 ! udpsink
> host=127.0.0.1 port=5000 \
> rtpbin.send_rtcp_src_0 ! udpsink host=127.0.0.1 port=5001 sync=false
> async=false \
> udpsrc port=5005 ! rtpbin.recv_rtcp_sink_0;

Doing retransmission with rtprtxqueue is not standard and usually not ideal.
That being said, this is likely the only way to enable RTX from launch syntax.
As enabling this is tedious, 1.17.1 (development release) includes new element
rtpsrc/rtsink which will take care of that for you, I greatly recommend to give
that a shot. If you are aiming to use that in your project, we aren't too far
from the release, so it's good idea to target this.

> 
> 
> RECEIVER: 
> gst-launch-1.0 -v rtpbin name=rtpbin do-retransmission=true latency=500 \
> udpsrc
> caps="application/x-rtp,media=(string)video,clock-rate=(int)90000,encoding-
> name=(string)H264"
> \
>              port=5000 ! rtpbin.recv_rtp_sink_0 \
> rtpbin. ! rtph264depay ! decodebin output-corrupt=true ! xvimagesink \
> udpsrc port=5001 ! rtpbin.recv_rtcp_sink_0 \
> rtpbin.send_rtcp_src_0 ! udpsink host=127.0.0.1 port=5005 sync=false
> async=false;
> 
> 
> For this, the retransmission mechanism does not work as expected. I am
> experiencing, probably all, packet loss, i.e., corrupt frames. On the
> receiver side, the rtx-count skyrockets (6376 after 19s). On the sender
> side, there is a negative number of lost packets (-1786 after 19s). See
> below the complete stats.  
> 
> Am I missing an important parameter or element in my pipelines? 
> 
> 
> Another question: Is there any more robust choice than above pipeline for
> minimal, latency video streaming of multiple cameras? H264 (with tunes
> zerolatency and preset ultrafast) seems like a good choice due low CPU load. 
> 
> Andi
> 
> 
> -v output from the SENDING PIPELINE: 
> /GstPipeline:pipeline0/GstRtpBin:rtpbin/GstRtpSession:rtpsession0: stats =
> application/x-rtp-session-stats, rtx-drop-count=(uint)0,
> sent-nack-count=(uint)0, recv-nack-count=(uint)117,
> source-stats=(GValueArray)< "application/x-rtp-source-stats\,\
> ssrc\=\(uint\)3302729844\,\ internal\=\(boolean\)false\,\
> validated\=\(boolean\)true\,\ received-bye\=\(boolean\)false\,\
> is-csrc\=\(boolean\)false\,\ is-sender\=\(boolean\)false\,\
> seqnum-base\=\(int\)-1\,\ clock-rate\=\(int\)-1\,\
> rtcp-from\=\(string\)127.0.0.1:51795\,\ octets-sent\=\(guint64\)0\,\
> packets-sent\=\(guint64\)0\,\ octets-received\=\(guint64\)0\,\
> packets-received\=\(guint64\)0\,\ bitrate\=\(guint64\)0\,\
> packets-lost\=\(int\)0\,\ jitter\=\(uint\)0\,\ sent-pli-count\=\(uint\)0\,\
> recv-pli-count\=\(uint\)0\,\ sent-fir-count\=\(uint\)0\,\
> recv-fir-count\=\(uint\)0\,\ sent-nack-count\=\(uint\)0\,\
> recv-nack-count\=\(uint\)0\,\ have-sr\=\(boolean\)false\,\
> sr-ntptime\=\(guint64\)0\,\ sr-rtptime\=\(uint\)0\,\
> sr-octet-count\=\(uint\)0\,\ sr-packet-count\=\(uint\)0\,\
> sent-rb\=\(boolean\)false\,\ sent-rb-fractionlost\=\(uint\)0\,\
> sent-rb-packetslost\=\(int\)0\,\ sent-rb-exthighestseq\=\(uint\)0\,\
> sent-rb-jitter\=\(uint\)0\,\ sent-rb-lsr\=\(uint\)0\,\
> sent-rb-dlsr\=\(uint\)0\,\ have-rb\=\(boolean\)true\,\
> rb-fractionlost\=\(uint\)0\,\ rb-packetslost\=\(int\)0\,\
> rb-exthighestseq\=\(uint\)10216\,\ rb-jitter\=\(uint\)0\,\
> rb-lsr\=\(uint\)1152762771\,\ rb-dlsr\=\(uint\)11998\,\
> rb-round-trip\=\(uint\)54\;", "application/x-rtp-source-stats\,\
> ssrc\=\(uint\)3116036975\,\ internal\=\(boolean\)true\,\
> validated\=\(boolean\)true\,\ received-bye\=\(boolean\)false\,\
> is-csrc\=\(boolean\)false\,\ is-sender\=\(boolean\)true\,\
> seqnum-base\=\(int\)10071\,\ clock-rate\=\(int\)90000\,\
> octets-sent\=\(guint64\)4996323\,\ packets-sent\=\(guint64\)3959\,\
> octets-received\=\(guint64\)4996323\,\ packets-received\=\(guint64\)1786\,\
> bitrate\=\(guint64\)2983649\,\ packets-lost\=\(int\)-1786\,\
> jitter\=\(uint\)0\,\ sent-pli-count\=\(uint\)0\,\
> recv-pli-count\=\(uint\)0\,\ sent-fir-count\=\(uint\)0\,\
> recv-fir-count\=\(uint\)0\,\ sent-nack-count\=\(uint\)0\,\
> recv-nack-count\=\(uint\)117\,\ have-sr\=\(boolean\)true\,\
> sr-ntptime\=\(guint64\)16328720465379218184\,\
> sr-rtptime\=\(uint\)2041153692\,\ sr-octet-count\=\(uint\)4996323\,\
> sr-packet-count\=\(uint\)3959\;" >, rtx-count=(uint)0;
> ^Chandling interrupt.
> Interrupt: Stopping pipeline ...
> Execution ended after 0:00:19.652469133
> Setting pipeline to PAUSED ...
> Setting pipeline to READY ...
> Setting pipeline to NULL ...
> Freeing pipeline ...
> 
> 
> -v output from the RECEIVING PIPELINE: 
> /GstPipeline:pipeline0/GstRtpBin:rtpbin/GstRtpSession:rtpsession0: stats =
> application/x-rtp-session-stats, rtx-drop-count=(uint)0,
> sent-nack-count=(uint)366, recv-nack-count=(uint)0,
> source-stats=(GValueArray)< "application/x-rtp-source-stats\,\
> ssrc\=\(uint\)3302729844\,\ internal\=\(boolean\)true\,\
> validated\=\(boolean\)true\,\ received-bye\=\(boolean\)false\,\
> is-csrc\=\(boolean\)false\,\ is-sender\=\(boolean\)false\,\
> seqnum-base\=\(int\)-1\,\ clock-rate\=\(int\)-1\,\
> octets-sent\=\(guint64\)0\,\ packets-sent\=\(guint64\)0\,\
> octets-received\=\(guint64\)0\,\ packets-received\=\(guint64\)0\,\
> bitrate\=\(guint64\)0\,\ packets-lost\=\(int\)0\,\ jitter\=\(uint\)0\,\
> sent-pli-count\=\(uint\)0\,\ recv-pli-count\=\(uint\)0\,\
> sent-fir-count\=\(uint\)0\,\ recv-fir-count\=\(uint\)0\,\
> sent-nack-count\=\(uint\)0\,\ recv-nack-count\=\(uint\)0\,\
> have-sr\=\(boolean\)false\,\ sr-ntptime\=\(guint64\)0\,\
> sr-rtptime\=\(uint\)0\,\ sr-octet-count\=\(uint\)0\,\
> sr-packet-count\=\(uint\)0\;", "application/x-rtp-source-stats\,\
> ssrc\=\(uint\)3116036975\,\ internal\=\(boolean\)false\,\
> validated\=\(boolean\)true\,\ received-bye\=\(boolean\)false\,\
> is-csrc\=\(boolean\)false\,\ is-sender\=\(boolean\)true\,\
> seqnum-base\=\(int\)-1\,\ clock-rate\=\(int\)-1\,\
> rtp-from\=\(string\)127.0.0.1:39862\,\
> rtcp-from\=\(string\)127.0.0.1:53468\,\ octets-sent\=\(guint64\)0\,\
> packets-sent\=\(guint64\)0\,\ octets-received\=\(guint64\)6672117\,\
> packets-received\=\(guint64\)5244\,\ bitrate\=\(guint64\)3099889\,\
> packets-lost\=\(int\)-2082\,\ jitter\=\(uint\)0\,\
> sent-pli-count\=\(uint\)0\,\ recv-pli-count\=\(uint\)0\,\
> sent-fir-count\=\(uint\)0\,\ recv-fir-count\=\(uint\)0\,\
> sent-nack-count\=\(uint\)367\,\ recv-nack-count\=\(uint\)0\,\
> have-sr\=\(boolean\)true\,\ sr-ntptime\=\(guint64\)16328720465379218184\,\
> sr-rtptime\=\(uint\)2041153692\,\ sr-octet-count\=\(uint\)4996323\,\
> sr-packet-count\=\(uint\)3959\,\ sent-rb\=\(boolean\)true\,\
> sent-rb-fractionlost\=\(uint\)0\,\ sent-rb-packetslost\=\(int\)0\,\
> sent-rb-exthighestseq\=\(uint\)10216\,\ sent-rb-jitter\=\(uint\)0\,\
> sent-rb-lsr\=\(uint\)1152762771\,\ sent-rb-dlsr\=\(uint\)11998\,\
> have-rb\=\(boolean\)false\,\ rb-fractionlost\=\(uint\)0\,\
> rb-packetslost\=\(int\)0\,\ rb-exthighestseq\=\(uint\)0\,\
> rb-jitter\=\(uint\)0\,\ rb-lsr\=\(uint\)0\,\ rb-dlsr\=\(uint\)0\,\
> rb-round-trip\=\(uint\)0\;" >, rtx-count=(uint)6376;
> ^Chandling interrupt.
> Interrupt: Stopping pipeline ...
> Execution ended after 0:00:19.916776877
> Setting pipeline to PAUSED ...
> Setting pipeline to READY ...
> Setting pipeline to NULL ...
> Freeing pipeline ...
> 
> 
> 
> --
> Sent from: http://gstreamer-devel.966125.n4.nabble.com/
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