# rtpredenc

Encode Redundant Audio Data (RED) as per RFC 2198.

This element is mostly provided for chrome webrtc compatibility: chrome expects protection packets generated by rtpulpfecenc to be wrapped in RED packets for backward compatibility purposes, but does not actually make use of the redundant packets that could be encoded with this element.

As such, when used for that purpose, only the pt property should be set to a payload type different from both the protected and protection packets' payload types.

When using rtpbin, this element should be inserted through the request-fec-encoder signal.

## Example pipeline

     gst-launch-1.0 videotestsrc ! x264enc ! video/x-h264, profile=baseline ! rtph264pay pt=96 ! rtpulpfecenc percentage=100 pt=122 ! rtpredenc pt=122 distance=2 ! identity drop-probability=0.05 ! udpsink port=8888

This example will send a stream with RED and ULP FEC.

See also: rtpreddec, webrtcbin, rtpbin

## Hierarchy

    GObject
        ╰──GInitiallyUnowned
            ╰──GstObject
                ╰──GstElement
                    ╰──rtpredenc

## Factory details

Authors: – Hani Mustafa , Mikhail Fludkov

Classification: – `Codec/Payloader/Network/RTP`

Rank – none

Plugin – rtp

Package – GStreamer Good Plug-ins

## Pad Templates

### `sink`

    application/x-rtp:

Presence – always

Direction – sink

Object type – GstPad

### `src`

    application/x-rtp:

Presence – always

Direction – src

Object type – GstPad

## Properties

### allow-no-red-blocks

    “allow-no-red-blocks” gboolean

true - can produce RED packets even without redundant blocks (distance==0) false - RED packets will be produced only if distance>0

Flags : Read / Write

Default value : true

### distance

    “distance” guint

Tells which media packet to use as a redundant block (0 - no redundant blocks, 1 to use previous packet, 2 to use the packet before previous, etc.)

Flags : Read / Write

Default value : 0

### pt

    “pt” gint

Payload type FEC packets (-1 disable)

Flags : Read / Write

Default value : 0

### sent

    “sent” guint

Count of sent packets

Flags : Read

Default value : 0

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