Re: Dual Streaming Synchronization



OK well it should be possible to syncronise the two if they're both
video files (it would be quite hard, by comparison, to sync a video
and a powerpoint).

However, have you considered Producer for Powerpoint ?


It will make the encoding process simpler, though afaik you can't use
it to live video, it will create both the slides and camera input into
a web page for you .... just a thought :


I've got a lot of concern about using the digital to analog to digital
to compressed video with the steps you detailed below, you're sure to
lose a lot of quality and your screen captures may become impossible
to view text ;-)

It might be worth instead looking at running both powerpoint *and* the
encoder on the presenters laptop, with the encoder using the *screen
capture* profile to capture and encode the entire screen digitally.
You'd also have less wires, though you might need a faster laptop.

Cheers - Neil

On Thu, 28 Jul 2005 15:02:38 -0400, "vsta" <vsta2005@xxxxxxxxx> wrote:

>Hi Neil,
>
>Thanks for the info, that's great help from you. To confirm to you the
>#Screen Capture# is the video signal from the 15 pin Mini D-Sub video
>connection of the presenter laptop's screen. We use 2 intermediate devices
>to translate that into S-Video, then from S-Video to USB 2.0 which will then
>connected to the encoder that encode the signal to the stream server.
>
>Presenter's laptop ---> D-SubToS-Video ---> S-VideoToUSB2.0 --->
>Encoder ---> Stream server
>
>vsta
>
>"Neil Smith [MVP Digital Media]" <neil@xxxxxxxxxx> wrote in message
>news:44oee19fohnl3qpi5m3vnljkhqs7v153tc@xxxxxxxxxx
>> On Tue, 26 Jul 2005 12:30:33 -0400, "vsta" <vsta2005@xxxxxxxxx> wrote:
>>
>> >Hello All,
>> >
>> >We have clients that open a web page which embbed 2 video stream, one for
>> >the presentor and the other for his laptop screen capture (of the
>presentor
>> >presentation).
>> >
>> >How do we go about to have the 2 streams synchronize on the clients
>> >computer? Or at least reduce the gap between the 2 streams to an
>acceptable
>> >time period says 2 - 3 seconds?
>>
>> This is going to be quite hard to do (although as you say, it doesn't
>> have to be a precise zero-second delay)
>>
>> You would have to introduce some sort of javascript interlock between
>> the two streams so that Stream B waits for Stream A to begin, then
>> Stream A is paused until Stream B buffers and begins. You may find
>> this introduces a 'deadlock' where Stream A continues to wait for
>> Stream B to load only to find Stream A then buffers, making Stream B
>> wait. It would have to be programmed carefully and tested under
>> different network conditions.
>>
>> You may also run into problems with buffering in re-synchronising the
>> streams if one begins to buffer and the other continues to play.
>>
>> To confirm, the #screen capture# is coming from windows media encoder,
>> and the presentation is a separate, pre-formed Powerpoint file ? Or is
>> the presentation a .wmv video file streamed from a media or web
>> server?
>>
>> Cheers - Neil
>>
>

.