[MEncoder-users] Next-Gen YouTube type question.

[Robby Dermody]

Hi guys, video processing newbie here. :-) I have a question about
live/on-the-fly video transcoding and streaming. Specifically, for the
easiest end-user acceptance this may involve mencoder, the flv file format,
and a flv streaming server (lighttpd with appropriate plugin in this case).
Think about a YouTube type setup that allows users to watch videos live, as
they are being produced. FLV would be the format of choice due to the
widespread availability of Flash player, and the lack of ActiveX warnings,
java incompatibilities/speed, quicktime/realplayer hassles, etc. Seems like
Flash Just Works (witness Google Video and YouTube).

 

>From the research I've done, the setup would go like: 

take in LIVE video feed in format X from some source -> mencoder convert to
flv -> named pipe -> file location readable by lighttpd with flv-streaming
module setup, allows for live streaming of this file (with obvious
transcoding and network propagation delays)

 

After doing some research it seems that this wouldn't work, due to the lack
of metadata in the flv stream which the flv-streaming module and more
importantly flash player need. I'm not sure if the flv format can even be
composed and distributed on the fly like that. And, from looking at
flvtool2, it looks like the complete file needs to be in place before it can
write out this data? Is there any way to get the metadata data that flash
player needs in the flv as it's being output? Another possible issue is if
mencoder can reliably take data from stdin like that..it looks like it isn't
recommended.

 

Other alternatives involve using an activeX control to play a live ogg
theora/nsv stream produced in the same fashion and served up with
icecast/shoutcast. If FLV doesn't work out, I may ask the same question to
the xiph guys.

 

In any case, I would think the video producer app would either have to be an
activeX/java-type control or an actual application.

 

Any ideas from the resident gurus welcome.

 

Robby