7.8 KiB
RTMP (GStreamer command-line cheat sheet)
GStreamer can:
- retrieve an RTMP stream from an RTMP server, and
- also send an RTMP stream to an RTMP server (including YouTube).
If you need your own RTMP server, the Nginx RTMP extension works quite well. Linode has a good NGINX RTMP installation guide.
Play an RTMP stream
RTMP can be live streams, or on-demand streams - playback is the same in both cases.
To play from RTMP server, playbin can be used. (Playbin is magical - it can also play files, HLS streams, DASH streams, and many other sources!) Example:
export RTMP_SRC="rtmp://matthewc.co.uk/vod/scooter.flv"
gst-launch-1.0 playbin uri=$RTMP_SRC
A test RTMP VOD stream is available at rtmp://matthewc.co.uk/vod/scooter.flv which serves as a useful example:
Instead of using playbin, it's possible to get video only with uridecodebin then shown with autovideosink:
gst-launch-1.0 uridecodebin uri=$RTMP_SRC ! autovideosink
Or as a step further we can split out into the source and decode too. This does video:
gst-launch-1.0 rtmpsrc location=$RTMP_SRC ! decodebin ! autovideosink
and this does the audio:
gst-launch-1.0 rtmpsrc name=rtmpsrc location=$RTMP_SRC ! decodebin ! \
queue ! audioconvert ! autoaudiosink
We can vget flvdemux to pull out the audio:
gst-launch-1.0 rtmpsrc location=$RTMP_SRC ! \
flvdemux name=t t.audio ! decodebin ! autoaudiosink
Incidentally, all of these work with a direct flv file:
gst-launch-1.0 filesrc location="/path/to/test.flv" ! \
flvdemux name=t t.audio ! decodebin ! autoaudiosink
If you want to use flvdemux to do the video, you need to capture the audio too or else it will fail. This example puts it in fakesink which is basically discarding it:
gst-launch-1.0 rtmpsrc location="$RTMP_SRC" ! \
flvdemux name=demux \
demux.audio ! queue ! decodebin ! fakesink \
demux.video ! queue ! decodebin ! autovideosink
You could then use this to capture the RTMP as an MP4, e.g.
gst-launch-1.0 -e rtmpsrc location="$RTMP_SRC" ! \
flvdemux name=demux \
demux.audio ! queue ! decodebin ! audioconvert ! faac bitrate=32000 ! mux. \
demux.video ! queue ! decodebin ! videoconvert ! video/x-raw,format=I420 ! x264enc speed-preset=superfast tune=zerolatency psy-tune=grain sync-lookahead=5 bitrate=480 key-int-max=50 ref=2 ! mux. \
mp4mux name=mux ! filesink location="out.mp4"
According to this conversation, the following also works, although personally I find it intermittent:
export QUEUE="queue max-size-time=0 max-size-bytes=0 max-size-buffers=0"
gst-launch-1.0 \
rtmpsrc location="$RTMP_SRC live=1" ! \
$QUEUE ! \
flvdemux name=demux ! \
$QUEUE ! \
aacparse ! \
avdec_aac ! \
autoaudiosink sync=0 demux.video ! \
$QUEUE ! \
h264parse ! \
avdec_h264 ! \
$QUEUE ! \
videoconvert ! \
autovideosink sync=0
Adding an RTMP as picture-in-Picture
This overlays an RTMP source as a picture-in-picture on top of a local filesource (set as $SRC)
export QUEUE="queue max-size-time=0 max-size-bytes=0 max-size-buffers=0"
gst-launch-1.0 \
filesrc location="$SRC" ! \
decodebin ! videoconvert ! \
videoscale ! video/x-raw,width=640,height=360 ! \
compositor name=mix sink_0::alpha=1 sink_1::alpha=1 sink_1::xpos=50 sink_1::ypos=50 ! \
videoconvert ! autovideosink \
rtmpsrc location="$RTMP_SRC" ! \
flvdemux name=demux \
demux.audio ! $QUEUE ! decodebin ! autoaudiosink \
demux.video ! $QUEUE ! decodebin ! \
videoconvert ! \
videoscale ! video/x-raw,width=320,height=180! \
mix.
Sending a live stream to an RTMP server
The examples below use the RTMP_DEST environment variable. You can set it to reference your RTMP server, e.g.
export RTMP_DEST="rtmp://example.com/live/test"
If you're using Nginx RTMP, the name configured for your application needs to be the first part of the URL path. For example, if your NGINX configuration is:
rtmp {
server {
listen 1935;
hunk_size 4096;
notify_method get;
application livestream {
live on;
}
}
}
then the application name is livestream, and so your URL will be rtmp://<your-domain>/livestream/<stream-name> (where <stream-name> can be anything).
Sending a test live stream to an RTMP server
To send a video test source:
gst-launch-1.0 videotestsrc is-live=true ! \
queue ! x264enc ! flvmux name=muxer ! rtmpsink location="$RTMP_DEST live=1"
To send an audio test source (note: flvmux is still required even though there is no muxing of audio & video):
gst-launch-1.0 audiotestsrc is-live=true ! \
audioconvert ! audioresample ! audio/x-raw,rate=48000 ! \
voaacenc bitrate=96000 ! audio/mpeg ! aacparse ! audio/mpeg, mpegversion=4 ! \
flvmux name=mux ! \
rtmpsink location=$RTMP_DEST
This sends both video and audio as a test source:
gst-launch-1.0 videotestsrc is-live=true ! \
videoconvert ! x264enc bitrate=1000 tune=zerolatency ! video/x-h264 ! h264parse ! \
video/x-h264 ! queue ! flvmux name=mux ! \
rtmpsink location=$RTMP_DEST audiotestsrc is-live=true ! \
audioconvert ! audioresample ! audio/x-raw,rate=48000 ! \
voaacenc bitrate=96000 ! audio/mpeg ! aacparse ! audio/mpeg, mpegversion=4 ! mux.
Live streaming to YouTube via RTMP
YouTube accepts live RTMP streams. They must have both audio and video.
Set up a stream by visiting YouTube.com on desktop, and selecting 'Create' from the top-right.
YouTube will provide a 'Stream URL' and a 'Stream key'. Combine these to create the full URL.
For example, if the URL is rtmp://a.rtmp.youtube.com/live2 and the key is abcd-1234-5678, then:
export RTMP_DEST="rtmp://a.rtmp.youtube.com/live2/abcd-1234-5678"
Given the YouTube stream suggestions) here's a good test stream:
gst-launch-1.0 \
videotestsrc is-live=1 \
! videoconvert \
! "video/x-raw, width=1280, height=720, framerate=30/1" \
! queue \
! x264enc cabac=1 bframes=2 ref=1 \
! "video/x-h264,profile=main" \
! flvmux streamable=true name=mux \
! rtmpsink location="${RTMP_DEST} live=1" \
audiotestsrc is-live=1 wave=ticks \
! voaacenc bitrate=128000 \
! mux.
Send a file over RTMP
Audio & video:
gst-launch-1.0 filesrc location=$SRC ! \
qtdemux name=demux \
demux.video_0 ! queue ! \
decodebin ! videoconvert ! x264enc bitrate=1000 tune=zerolatency ! video/x-h264 ! h264parse ! \
video/x-h264 ! queue ! flvmux name=mux ! \
rtmpsink location=$RTMP_DEST \
demux.audio_0 ! queue ! decodebin ! audioconvert ! audioresample ! \
audio/x-raw,rate=48000 ! \
voaacenc bitrate=96000 ! audio/mpeg ! aacparse ! audio/mpeg, mpegversion=4 ! mux.
Just video:
gst-launch-1.0 filesrc location=$SRC ! \
qtdemux name=demux \
demux.video_0 ! queue ! \
decodebin ! videoconvert ! x264enc bitrate=1000 tune=zerolatency ! video/x-h264 ! h264parse ! \
video/x-h264 ! queue ! flvmux name=mux ! \
rtmpsink location=$RTMP_DEST
Misc: latency
There's a comment about reducing latency at https://lists.freedesktop.org/archives/gstreamer-devel/2018-June/068076.html