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58 lines
2.5 KiB
Markdown
58 lines
2.5 KiB
Markdown
# Multiple outputs (tee)
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This page describes the `tee` element, which allows audio & video streams to be sent to more than one place.
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## Tee to two local video outputs
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Here's a simple example that sends shows video test source twice (using `autovideosink`)
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```
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# The two windows may overlay on top of each other
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gst-launch-1.0 \
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videotestsrc ! tee name=t \
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t. ! queue ! videoconvert ! autovideosink \
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t. ! queue ! videoconvert ! autovideosink
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```
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## Tee to two different video outputs
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Here's an example that sends video to both `autovideosink` and a TCP server (`tcpserversink`).
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Note how `async=false` is required on both sinks, because the encoding step on the TCP branch takes longer, and so the timing will be different.
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```
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gst-launch-1.0 videotestsrc ! \
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decodebin ! tee name=t \
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t. ! queue ! videoconvert ! autovideosink async=false \
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t. ! queue ! x264enc ! mpegtsmux ! tcpserversink port=7001 host=127.0.0.1 recover-policy=keyframe sync-method=latest-keyframe async=false
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```
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However, as discussed [here](http://gstreamer-devel.966125.n4.nabble.com/tee-won-t-go-in-playing-state-td4680128.html), `async=false` can cause issues. Adding `tune=zerolatency` to the `x264enc` also resolves the issue, by telling the encoding step not to add a delay, and thus making its branch as quick as the `autovideosink` one.
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```
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gst-launch-1.0 videotestsrc ! \
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decodebin ! tee name=t \
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t. ! queue ! videoconvert ! autovideosink \
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t. ! queue ! x264enc tune=zerolatency ! mpegtsmux ! tcpserversink port=7001 host=127.0.0.1 recover-policy=keyframe sync-method=latest-keyframe
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```
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Or, if you'd rather not reduce the quality of x264 encoding, you can increase the queue size:
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```
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gst-launch-1.0 videotestsrc ! \
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decodebin ! tee name=t \
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t. ! queue max-size-time=3000000000 ! videoconvert ! autovideosink \
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t. ! queue ! x264enc ! mpegtsmux ! tcpserversink port=7001 host=127.0.0.1 recover-policy=keyframe sync-method=latest-keyframe
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```
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## Tee on inputs
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You can also use `tee` in order to do multiple things with inputs. This example combines two audio visualisations:
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```
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gst-launch-1.0 filesrc location=$SRC ! decodebin ! tee name=t ! \
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queue ! audioconvert ! wavescope style=color-lines shade-amount=0x00080402 ! alpha alpha=0.5 ! \
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videomixer name=m background=black ! videoconvert ! vertigotv ! autovideosink \
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t. ! queue ! audioconvert ! spacescope style=color-lines shade-amount=0x00080402 ! alpha alpha=0.5 ! m. \
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t. ! queue ! autoaudiosink
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```
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