GStreamer Daemon - Flush start/Flush stop
This wiki shows how to send a flush event to a given pipeline. Sometimes it is important to flush a current pipeline and then restart the flushing pipeline.
Sending an flush start event
Elements should unlock functions when some function is blocked once the event is received with a success code. This event flush all queued data in the pipeline for new media play.
A new flush start event is sent to a pipeline using the command shown below.
event_flush_start pipeline
Creates a new flush start event and sends it to pipeline.
Sending an flush stop event
Allocate a new flush stop event. This event should send after a flush start event, to able the pad and receives data. When this event is completed sends a seek and resume dataflow.
A new flush stop event is sent to a pipeline using the command shown below.
event_flush_stop pipeline reset=true
Creates a new flush stop event and sends it to pipeline.
For example:
⇒ Gstd Commands:
1 pipeline_create p1 videotestsrc ! autovideosink
2 pipeline_play p1
3 event_flush_start p1
4 event_flush_stop p1 true
5 pipeline_stop p1
6 pipeline_play p1
will respectively
- Create a pipeline p1
- Put it to playing
- Send a flush start event to it
- Send a flush stop event to it
- Put it to stop p1
- Put it to playing
The event_flush command will typically fail for any of the following:
- No pipeline was given
- The given pipeline doesn't exist
- Wrong flush event property
Alternatively, a pipeline can be created using the low level CRUD syntax:
⇒ Gstd Commands:
1 create /pipelines/p1/event flush_start
2 create /pipelines/p1/event flush_stop true
API Summary
| High Level Command | Low Level CRUD | Description |
|---|---|---|
| event_flush_start <pipeline> | create /pipelines/<name>/event flush_start | Put the pipeline in flushing mode |
| event_flush_stop <pipeline> <reset=true> | create /pipelines/<name>/event flush_stop <reset=true> | Take the pipeline out of flushing mode |
