The MultiView decodes VBX-MultiSource format digital video (Motion JPEG) and audio streams to reconstitute conventional analogue signals. It will also encode a single analogue audio input for transmission over the ATM network.
We captured a sample screen dump (104K JPEG) of output from an ATV. The display shown consists of four seperate video streams that are incoming from different MultiSources around the ATM network. The streams displayed have been produced from a mixture of PAL and NTSC sources. A sample menu has also been selected using the MultiView infra-red remote control.
When combined with the MultiSource series products and SVA software the MultiView fulfils the next generation application enabling capabilitities of ATM:
The MultiView unit has a single analogue video output signal that is duplicated on four RCA/Phono sockets. Two of the sockets are used to provide a high quality S-VIDEO output. The remaining two sockets provide two composite versions of the same signal. The analogue output standard can be configured locally or by remote management/control software. The choices are:
The MultiView accepts Motion JPEG digital video streams in MultiSource compatible format from the ATM network. The MultiView complements the extensive flexibility that is present in the MultiSource series products by being able to accept multiple input streams with different sizes, frame rates, compression factors and even source analogue format (e.g. PAL and NTSC). These streams may be displayed concurrently in a tiled format or in more limited cases as moveable picture-in-picture output.
The MultiView has a single stereo RCA/Phono socket analogue audio output. Digital streams in MultiSource compatible format may be taken from the network and the analogue signal re-constituted. Multiple digital audio streams may be input to the MultiView simultaneously but only one can be selected for play out at a particular point in time. The MultiView supports all audio sampling modes and rates that can be generated by the MultiSource encoder i.e:
The MultiView uses a 24-bit video overlay plane to provide a comprehensive on screen menu system. The menu system may be driven either using an infra-red transmitter or by a mouse. A particular menu may be created either by software running in the ATV or by remote management software (please refer to the SVA page). Future SVA applications will make extensive use of this facility. Examples of currently supported local menu selection functions include:
The MultiSource control capability allows the MultiView to directly configure a remote MultiView to which it is connected by PVCs or SVCs. The MultiView user is able to switch between audio and video channels on the remote MultiSource. The user may also alter the frame rate and compression factor of the video at source.
The MultiView (serial) mouse interface may be used to drive the menu system. In addition the mouse allows a few short cuts when examing the attributes of particular streams that are being displayed on the screen. The mouse may also be used to drag video images around the screen when the MultiView is operating in picture-in-picture mode.
In order to configure video and audio streams the MultiView repsonds to a control protocol based on AAL5 PDUs. The SVA software provides a comprehensive set of interfaces to this protocol as well as higher level applications. The MultiView is capable of operating in both a Fore Systems SPANS and ATM Forum UNI 3.0/3.1 SVC environment. ATM.
The speed with which ATM encodings are being defined for both legacy and replacement transmission interfaces has dictated that the MultiView transmission system is fitted as a customer selectable PMD daughter board. Currently supported interfaces is :
The MultiView is fully controllable over the ATM network by VideoBOX SVA software. Additionally extensive configuration may be performed using the local menu system interface. However, in some instances it is desirable to have the MultiView operate in standalone mode without having to depend on any remote software or local user input.
The External Configuration Module (ECM) is an MultiView option that allows a user to configure a permanent power on video and audio stream configuration. If power is lost to the MultiView and then restored the MultiView will start executing with the configuration present, if enabled, in its ECM. The ECM contents may be changed over the ATM network.
