PushPublish and timecodes

Wowza Streaming Engine
1

Hello All,

I’m looking for some help explaining the timecodes when using wowza to convert an MPEG-TS (over udp) to a RTMP push into a Flash Media Server.

The PushPublish module has publisher.setSendOriginalTimecodes(…).

If set to true, where in the MPEG-TS do the timecodes come from?

If set to false, how are the timecodes generated?

The CDN is stating they are seeing timecode issues in the FMS logs. It may be causing issues to stability.

Edit:

This is the log from the FMS:

013-06-27 20:09:31 22494 (w)2611179 Warning from libf4f.so: [Utils] [stream1] [stream1] FMS F4F recording received timestamps with absolute time flowing backward lastTime held was 31690848 and the most recent arrived was 31690153. This message is being ignored - recording will continue.

Edit 2:

Adobe has told me that the message above is in refference to the DTS in the PES. Is the anything in Wowza that can alter the DTS or other timecodes/timestamps? I’m not using any transcoding at this time, just MPEG-TS (udp) in and RTMP (PushPublish) out.

Thank you for the help.

Austin

2

Hello,

In trying to understand how the backward timestamp can occur, what happens if the ip packets are received in wowza out of order on an mpeg-ts over UDP without RTP? Is there any buffering and reordering done? What is the effect on the reconstruction of the mpeg-ts if this happens?

Thanks

Austin

3

Austin,

The problem might originate in the encoder, or packets might arrive out of order because of network issues. Wowza cannot re-order packets in mpeg-ts over udp, but you can use the Jitter Buffer to debug:

https://www.wowza.com/docs/how-to-turn-on-an-rtp-jitter-buffer-and-packet-loss-logging-rtp-and-mpeg-ts

Richard

4

The jitter buffer will only help debug packet loss for mpeg-ts over udp.

I think the push publisher inserts new time codes if setSendOriginalTimecodes is not set to true.

Richard

5

Thanks Richard.

Will the Jitter Buffer work (help) with mpeg-ts over udp? Or are you talking about the debugging for packet loss?

If packets are received out of order are the discarded or just sent on to the PushPublisher?

If they are received out of order, is there any logging I can see within wowza?

Sorry for all the questions.

Austin