Technological Setup for the Informal Screenings
A technological description by HfG
From a technology viewpoint for the Informal Screenings a lean, yet efficient mode of transmission via Internet was researched. Reducing the machines to a minimum and with easily accessible software components the public events and the therein presented electronic art content were to be made available via video stream on the internet to the public.
To this end, it was necessary to combine different content.
On the side of the organizers the primary concern lay in testing how a wide specter of different play-back machines might be made compatible for the web. The scope of machines was:
- play-back of DVD
- live feed from MiniDV
- digitized sequences directly from the PC
- feeding of VHS and potentially UMATIC by tapping the video signal
- in addition the video stream which was to go online was to be mixed with the live camera in the venue
Lacking a professional video mixing console, a video scaler was used, which allowed switching between the input signals DV, Video, S-Video and the separately mixed sound without creating gaps in the signal.
Despite working with a minimum of machines it was necessary to create an unbroken video stream, which was then encoded in real time by the coding machine and then fed online as a web stream.
The Technical Chart
The following machines were used:
Signal path
Like the connection schema in table 8 the scaler toggled the video signal between the different sources (recording camera and play-back machines). In addition, the mixed audio signal was mixed with the video signal and sent via firewire (DV Output) to the encoding machine (G5).
The audio signal was mixed on a seperate mixing desk. Input: the respectively connected play-back machine as well as the live microphone. Output: Stereo signal, which was split and played back in teh venue as well as transmitted to the scaler.
On the G5 the received video signal was processed in Quicktime Broadcaster and then transmitted as a live stream to the Quicktime Streamingserver of the HfG (for settings see below).
The rendition of the stream on the Internet was via a reference movie, which was integrated into a specially provided web page. For some presentations on the same page a chat window was provided below the stream, which allowed net users to comment the event and to put questions to the speakers.
In these cases a computer display was positioned for te speakers in such a manner that they were able to follow the transmission on the web (including time delays) and were able to react to comments.
Quicktime Broadcaster
Text coming soon, please follow this link for → preliminary information
Image 3 to 5: Setup Darwin Streaming Server at HfG
The Informal Screenings were streamed online via a Darwin streaming server with following configuration.
Besides the application to distribute content in real time, tests for the quasi real time distribution were conducted.
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