This is an example of multi-bitrate DASH streaming configuration. In this example Liquidsoap will be configured to output three different MPEGTS video streams with various frame size, bitrates and one stereo audio MPEGTS stream all via UDP. This configuration can be used with the same setup as my previous blog post about setting up Liquidsoap MPEGTS DASH streaming. This example is using Liquidsoap v1.3.3.
Please note that this is more of a proof of concept than practical use. A hardware encoder plugin for Gstreamer would help.
Liquidsoap Configuration: MPEGTS via UDP for Multi-Bitrate DASH Streaming
set("log.stdout",true)
set("log.level",5)
set("gstreamer.debug_level",2)
set("frame.video.width",1280)
set("frame.video.height",720)
set("frame.video.samplerate",25)
set("gstreamer.add_borders", true)
input = single("/home/user/Videos/Test/test-1280x720-25fps.ogv")
#MPEGTS Output For DASH Streaming.
#You must start Shaka Packager first before starting Liquidsoap.
#Audio Channel. Port 5000
output.gstreamer.audio(
pipeline=
"audioconvert ! fdkaacenc bitrate=128000 ! queue ! mpegtsmux alignment=7 name=muxer ! queue ! udpsink host=127.0.0.1 port=5000
sync=true",
mksafe(input))
#Video Channels.
#360p Video at 600kbps. Port 5001
output.gstreamer.video(
pipeline=
"videoscale ! video/x-raw,width=480,height=360 ! videoconvert ! x264enc bitrate=600 key-int-max=72 pass=qual quantizer=20 tune
=zerolatency ! video/x-h264,profile=baseline ! queue ! mpegtsmux alignment=7 name=muxer ! queue ! udpsink host=127.0.0.1 port=5001 s
ync=true",
mksafe(input))
#480p Video at 1000kbps. Port 5002
output.gstreamer.video(
pipeline=
"videoscale ! video/x-raw,width=640,height=480 ! videoconvert ! x264enc bitrate=1000 key-int-max=72 pass=qual quantizer=20 tun
e=zerolatency ! video/x-h264,profile=main ! queue ! mpegtsmux alignment=7 name=muxer ! queue ! udpsink host=127.0.0.1 port=5002 sync
=true",
mksafe(input))
#720p Video at 3000kbps. Port 5003
output.gstreamer.video(
pipeline=
"videoscale ! video/x-raw,width=1280,height=720 ! videoconvert ! x264enc bitrate=3000 key-int-max=72 pass=qual quantizer=20 tu
ne=zerolatency ! video/x-h264,profile=main ! queue ! mpegtsmux alignment=7 name=muxer ! queue ! udpsink host=127.0.0.1 port=5003 syn
c=true",
mksafe(input))
Shaka Packager Command
The packager will take the UDP output from Liquidsoap and encapsulate it into the DASH format for playback via the Shaka Player or any other DASH player.
$packager \ 'in=udp://127.0.0.1:5000?interface=127.0.0.1,stream=audio,init_segment=audio_init.mp4,segment_template=audio_$Number$.m4s' \ 'in=udp://127.0.0.1:5001?interface=127.0.0.1,stream=video,init_segment=h264_360p_init.mp4,segment_template=h264_360p_$Number$.m4s' \ 'in=udp://127.0.0.1:5002?interface=127.0.0.1,stream=video,init_segment=h264_480p_init.mp4,segment_template=h264_480p_$Number$.m4s' \ 'in=udp://127.0.0.1:5003?interface=127.0.0.1,stream=video,init_segment=h264_720p_init.mp4,segment_template=h264_720p_$Number$.m4s' \ --temp_dir /home/user/tmp -mpd_output test_h264.mpd
That is pretty much all there is to it. You could add higher or lower frame size and bitrates if you wanted to. However, this configuration is pushing the limits of Liquidsoap.
