Deadlock on mixing live and file sources.

Axel Philipsenburg philipsenburg at
Thu Jul 25 05:45:06 PDT 2013

Hi everyone,

I'm looking for some help to figure out my following problem:

We have two sources to our pipeline. One MP4 file on the local
harddisk and an rtmpsrc that reads a live stream off an RTMP server.

Both video streams get a timeoverlay for debug info and then get mixed
with the videomixer element. The output stream gets yet another

In the past, this worked fine with only-file sources. Now that I
have replaced one source with an RTMP live stream I get the following

The file video stream starts playing a few frames, its timeoverlay
showing the same value as the output stream's overlay.

Once the RTMP stream gets its first I Frame, the image shows up in the
mix with its timeroverlay showing the time since when the stream has
started to broadcast to the RTMP server.

For example I see 00:00:01.21 timestamps for the file source and the
output stream, but the live stream shows 01:23:45.67

The problem is, that the mixer output freezes in this moment. But there
is no error message or switch in the pipeline state. I also see the
rtmpsrc still pulling in data via the network.

My guess is, that the pipeline tries to synchronize the two streams
according to their timestamps, which is of course not possible.

Both sources use the decodebin element to process the filesrc or rtmpsrc
input. I'm using gstreamer 1.0.6 by the way.

Can anyone provide me with some hints on how to address this problem? Do
I need to set some element's properties?

Thanks a lot in advance!




Mit freundlichen Gruessen / best regards
papaya Software GmbH

i.A. Axel Philipsenburg

papaya Software GmbH | Im MediaPark 5 | 50670 Koeln | Germany
Tel./Ph.: +49-221-5743-8072 | Fax: +49-221-5743-8099
mailto:philipsenburg at |
Geschaeftsfuehrer: André Schnitzler, Daniel Schäfer
Sitz & Registergericht: Koeln | HRB 60030 | USt.-Id.-Nr.: DE 255642963

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