Wowza Community

Is possible transconding files on demand?


I have a client that has thousands of videos files in flv, not H254. He need show video on iphone/ipad. Is possible transconding files to H254?

thank you

Wowza Transcoder AddOn supports live feed, not on demand.


We recommend MS Expression 4 Encoder because it encodes key frame aligned sets, as is necessary for switching in multi-bitrate streaming.


The key frame alignment part is difficult. I have heard that can do it (recently from customer) but my only success has been with MS Expression 4. I don’t think ffmpeg can do it.


There is a round-about way. First follow this guide to setup live multi-bitrate stream set using Stream class streams with your files as the source:

Then add this Property:

Then check the key frame timecodes that are logged for each stream in access log to see how they align.


Hello nick_g,

  1. You could potentially use the StreamClassExample with Playlists do create a streamname which you could then feed into the Wowza transcoder. But it would not be “On Demand” exactly, unless you wrote some code to create the playlists. And then how many VOD files will you be able to transcode on the fly? 30, 50, 100? It just makes more sense to transcode the VOD files offline and then you will be able to stream to thousands of users. And you will only be transcoding them one time, instead of over and over.

  2. Those distros should work.

There are a few methods listed here:

Take a look at the ffmpeg example.

I should add that the Wowza Transcoder supports these video and audio codecs:

Video decoding: H.264, MPEG2, MPEG4 Part 2

Video encoding: H.264

Audio decoding: AAC, MP3, MPEG 1 Part 1/2, Speex, G.711 (a-law and mu-law)

Audio encoding: AAC



  1. Is there any way to play a video on demand file using Wowza Transcoder? Maybe using Server-side Modules or Extensions?

  2. Will Wowza Transcoder support Linux distro - CentOs or Debian?

Thanks randall.

Can anybody give advise which encoder to use? I need server side encoder based on linux distro. Encoder have to support Multi-birate encoding because a need to play video on demand with Adaptive Streaming

Yes I read this article. But it isn’t server side encoder and it requires Windows Server.

Is there any other product for multi-bitrate streaming encoding, compatible with Wowza Adaptive Bitrate Streaming?

I configured Wowza to play a video on demand file and it works fine, but now there is a problem with preparing video files.

Can you give me an advice? How I can check, if the encoded video has key frame alignment?

I try to find encoder, but I don’t know how check encoded video files.

Thanks, I will try it.