Properties

Types and Values

Object Hierarchy

    GObject
    ╰── GInitiallyUnowned
        ╰── GstObject
            ╰── GstElement
                ╰── GstRtpUlpFecDec

Description

Generic Forward Error Correction (FEC) decoder for Uneven Level Protection (ULP) as described in RFC 5109.

It differs from the RFC in one important way, it multiplexes the FEC packets in the same sequence number as media packets. This is to be compatible with libwebrtc as using in Google Chrome and with Microsoft Lync / Skype for Business.

This element will work in combination with an upstream GstRtpStorage element and attempt to recover packets declared lost through custom 'GstRTPPacketLost' events, usually emitted by GstRtpJitterBuffer.

If no storage is provided using the “storage” property, it will try to get it from an element upstream.

Additionally, the payload types of the protection packets *must* be provided to this element via its “pt” property.

When using GstRtpBin, this element should be inserted through the “request-fec-decoder” signal.

1

gst-launch-1.0 udpsrc port=8888 caps="application/x-rtp, payload=96, clock-rate=90000" ! rtpstorage size-time=220000000 ! rtpssrcdemux ! application/x-rtp, payload=96, clock-rate=90000, media=video, encoding-name=H264 ! rtpjitterbuffer do-lost=1 latency=200 !  rtpulpfecdec pt=122 ! rtph264depay ! avdec_h264 ! videoconvert ! autovideosink

See also: GstRtpUlpFecEnc, GstRtpBin, GstRtpStorage

Functions

Types and Values

struct GstRtpUlpFecDec;

Property Details

  “pt”                       guint

  “recovered”                guint

  “storage”                  GObject *

  “unrecovered”              guint