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Out of order packets and green screen artefacts on live streams.

If you ever have some out of order packets and green screen artefacts on live streams, the complete explanation of this issue and the solution follows.

 

For a universal live stream (stream packaging live), one of both of the following symptoms may show:

the HDS stream displays Jitters
the HLS stream displays green screen or artefacts

Applies To Stream Packaging (THIS IS WHAT DACAST USES)

Explanation

This occurs if the encoder is sending in Out of order timestamps.

That is, if the encoder is sending a number of packets (let's assume 10) each of these have a timestamp. This timestamp value should always be increasing. If these values are not in order, there can be complications during playback. Media Services Live for Stream Packaging requires FLV timestamp data from the RTMP encoder to be in increasing order regardless of types (audio/video/metadata/etc.).

Note: Keep in mind that Adobe's RTMP specification only requires that timestamps be increasing within a type. Timestamps can be out of order across different types. On the contrary, Akamai requires timestamps monotonically increasing across types.

Solution

Please try the following to resolve the issue:

Restart the encoder - the encoder may reset all values and start sending ordered packets.

Try streaming with an FMLE encoder to check if the same behavior is observed on these streams.

You might also need to escalate the issue to your encoder vendor to fix the timestamp ordering.

These informations come from Akamai CDN directly.

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