Wowza Community

Transcoder Issues - Jerky video/Low Frame Rates

Hi there,

I’ve just setup an EC2 instance with a Wowza AMI v4.0.1 (as suggested on the guides) and am sending a 5mbps stream from Wirecast to transrate with the Transcoder AddOn to 4 different bitrates.

When I first streamed, I noticed in the logs it had defaulted to to weird frame rate so used the sourceStreamFrameRate property to set this at 25 and all seemed ok after a restart.

However, after maybe 5-10 mins the transcoded video looks jerky like it’s around half the frame rate. I’ve check this on iOS devices, my own JW Player and the built in Wowza test players and they all confirm my Wirecast encoded incoming stream looks clean, just the Transcoder output does not.

CPU usage on the c1.xlarge doesn’t get much past 20%.

Could anyone take a look at this in the support department at Wowza?


Please refer to ticket


moving forward.

Was this resolved with Wirecast 5.0.3?

Hi All,

After some quick work by Matt here my issue seemed to be caused by Wirecast’s x264 codec. Using the h264 codec solved this.


I was using 5.0.3 when this issue occured.

I am not able to find ticket 89359, can you please share the link to the same

This is an outdated post. Please post a new question with the issue you are having since so much has changed since 2014. But, the only thing the ticket had suggested to do was this:

  1. Change the encoder setting to h264 in wirecast

  2. Restart Wowza and test the new encoder setting.