This page describes the ViewStation's HDS netTV
Simulcast Video Client manual page.
HDS NetTV Simulcast
Manual Page
NAME
hdssimulcast - Multicast video and audio to other ViewStations
SYNOPSIS
hdssimulcast [ -sendvid ] [ -sendaud ]
[ -send ] [ -localvol (0 to 100) ] [ -outvol (1 to 100) ] [
-compressioncompressiontype ] [ -large ] [ -connector connector ] [
-informat format ] [ -brightness (-30 to 30) ] [ -contrast (-30 to 30) ]
[ -saturation (-30 to30) ] [ -tint (-30 to 30) ] [ -indev
audioinputdevice ] [ -outdev audiooutputdevice ] [ - netlimit (0 to
4096) ] [ -quality (0 to 100) ] [ -mcast address ] [ -vidport
networkportnum ] [ -audport networkportnum ] [ -ttl multicasttimetolive
] [ -noaudio ] [ - toolkitOption ... ]
DESCRIPTION
hdssimulcast uses IP Multicasting technology to efficiently
transmit video and audio to a potentially large number of HDS NetTV
Viewer applications running on other networked HDS ViewStations. It is
similar to a real-life TV broadcasting station, except that the network
is being used to carry the television signals instead of the airwaves
or special-purpose cable.
To view the multicast transmissions on other ViewStations, you
must use the HDS NetTV Viewer (hdsnettv) program. The HDS NetTV Viewer
program can be run on any ViewStation and does not require the optional
HDS netVideo hardware. As discussed below, if you change the Simulcast
Network Addresses, make sure to set the HDS NetTV Viewer Network
Addresses to match.
The live video sources can include the output of a typical
video camera (such as the HDS ViewCam), a VCR, the optional HDS Tuner
output, or some other video-producing device. The video source should be
connected to the VIDEO connector on the ViewStation. If using the
optional HDS Tuner device, be sure to connect the Video Out from the
Tuner to the VIDEO connector on the ViewStation.
To transmit audio, an audio input device should be connected
to the ViewStation's AUDIO IN connector. This could be the HDS ViewCam's
audio cable, the HDS Headset, the echo-suppressing CallPort
Speaker/Microphone, the HDS Tuner, or VCR audio output. An alternate
audio output device can also be used.
Once the audio devices are attached, the ViewStation must be
configured to recognize them. The audio device types should be set in
the HDS Setup menu. See the descriptions of the audio Input Device and
Output Device below for more information.
Before sending video or audio on the network, you may need to
configure the Network Addresses under the Options menu. The network
addresses correspond (roughly) to the broadcast "channel" carrying your
HDS Simulcast program. You should choose addresses which do not
conflict with any other simulcasts currently being used on your
networks. See below for more details.
The Local Volume controls the volume of the audio speaker on
the local machine. However, it does not affect the volume of the signal
which is multicast over the network.
The Outgoing Volume slider controls the level of the audio
signal which is sent out over the network. It adjusts the amount of
gain applied to the Audio In Device. This volume should not normally
need to be adjusted, except by very small amounts. When it is adjusted
properly, the Audio meter level should generally stay in the safe green
level, occasionally straying into the red zone for louder sounds. It
should not be consistently in the red zone, or audio quality may suffer
considerably. The Outgoing Volume slider will also affect the local
volume.
The Audio meter indicates the level of the current Audio Input
Device attached to the AUDIO IN connector. The meter is continuously
updated, even when not transmitting audio. If the level is not
registering green for most sounds, make sure the Audio In Device is set
properly, the device is properly connected, and the Out going Volume
slider is properly adjusted.
The Send Video button must be used to actually begin
transmitting video over the network. Pressing the button again stops
the video sending. Video is only transmitted if this button is
highlighted.
The Send Audio button must be used to actually begin
transmitting audio over the network. Pressing the button again stops
the audio sending. Audio is only transmitted if this button is
highlighted.
The Freeze button can be used to freeze the outgoing video
image. Pressing the button again clears the freeze.
The Mute button can be used to mute the local audio
temporarily. It does not affect the outgoing volume. To mute the
outgoing volume, disable the Send Audio toggle.
The Options menu contains entries for the Video Controls,
Audio Controls, Network Controls, and Network Addresses panels.
The Video Controls panel contains the following items.
The Compression panel item controls the type of video
compression to use for the outgoing video transmission. The compression
lowers the outgoing network usage, but can decrease the overall image
quality. The compressions available are: None, CellB, and HDSGrey. The
CellB compression scheme provides good image compression for color
images. The HDSGrey compression scheme provides only black-and-white
transmission.
The Outgoing Resolution item controls the size of the local
and outgoing image. The two available values are 160 x 120 and 320 x
240. Using the smaller image size usually provides smoother motion and
higher frame rates.
The Input Connector item selects which type of video signal is
attached to the ViewStation. The default is the Composite signal which
is a single-plug jack. Another option is the S-Video connector which
has multiple pins and which separates color information from luminance
information. If set incorrectly, the ViewStation video display may
appear black-and-white or otherwise incorrect.
The Input Format item indicates which type of video signal
format is being used. The default is NTSC which is the standard for
North America and several other regions. Other options are PAL which is
dominant in Europe, and SECAM which is dominant in France. Once you
determine the standard for your equipment, you will usually use one
setting exclusively.
The Brightness, Contrast, Saturation, and
Tint sliders control the video characteristics of the video window.
The Audio Controls panel contains the following items.
The Input Device item indicates the type of device attached to
the ViewStation's AUDIO IN connector. This value must be set properly
or the ViewStation's audio will not operate correctly. The initial
value for the input device comes from the ViewStation's Setup client.
It is better to make any changes to this value in the Setup client menu
"Setup Options/User Preferences/Audio Device Settings/ Audio In Device"
and save the value for the future. NOTE: It is important to change this
value whenever you change the audio device attached to the ViewStation.
Otherwise, the ViewStation will not know what type of device is attached
and severe audio quality problems will result. The input device can be
set to "Unspecified", "HDS ViewCam", "HDS Headset", "CallPort
Spkr/Mic", "HDS Microphone", "HDS Tuner", "VCR", or "Line Level Audio".
The "Line Level Audio" category refers to the output level of many
common home audio devices, such as CD players and cassette decks.
The Output Device item indicates the type of device attached
to the ViewStation's AUDIO OUT connector. This value must be set
properly or the ViewStation's audio will not operate correctly. As with
the Input Device, the initial value for the output device comes from
the ViewStation's Setup client. It is better to make any changes to
this value in the Setup menu "Setup Options/User Preferences/Audio
Device Settings/Audio Out Device" and save the value for the future.
NOTE: It is important to change this value whenever you change the
audio device attached to the ViewStation. Otherwise, the ViewStation
will not know what type of device is attached and severe audio quality
problems will result. The output device can be set to "HDS Internal
Speaker", "External Speakers", "HDS Headset", or "CallPort Spkr/Mic".
The Network Controls panel contains the following items.
The Outgoing Rate item shows the number of outgoing video
frames per second. This can be affected by the Quality and Compression
settings.The Outgoing Net Use item shows the amount of network use for
the outgoing audio and video connections. This can be affected by the
Quality and Compression settings.
The Net Use Limit slider sets the maximum allowed network use.
The default is 4096. Decreasing the value can result in decreased frame
rates and in motion which is not as smooth. You can adjust this value
to suit your needs.
The Quality slider controls the general quality of the out-
going image. It gener ally controls how much of a change must occur in
an area of the screen before it must be retransmitted to the receiver.
The default is 100, which means the entire image is sent each frame.
Lower values reduce the amount of outgoing network usage, but also
reduce the quality of the image.
The Network Addresses panel contains the following items.
The Multicast Net Address item gives the destination IP
address for the hdssimul cast output. The IP address is a multicast
address if it is in the form aaa.bbb.ccc.ddd where aaa is between 224
and 239. If a multicast address is specified, then all receivers
listening to that multicast group "channel" can receive the simulcast.
If you want to specify a single receiver, you can use a non-multicast
(uni-cast) address. The default value is 224.2.1.1. The hdsnettv viewer
program's Multicast Net Address must be set to match in order to
receive the transmissions.
The Video Net Port can be used to specify the UDP network port
number for the outgoing video packets. The default value is 4444. Note
that the the hdsnettv viewer program's Video Net Port must be set to
match in order to receive the transmissions.
The Audio Net Port can be used to specify the UDP network port
number for the outgoing video packets. The default value is 4445. Note
that the the hdsnettv viewer program's Audio Net Port must be set to
match in order to receive the transmissions.
OPTIONS
In addition to the usual Xt and Motif options, hdssimulcast
supports the follow ing application-specific options.
-sendvid
Indicates that video should be sent automatically.
-sendaud
Indicates that audio should be sent automatically.
-send
Indicates that both video and audio should be sent automatically.
-localvol (0 to 100)
Set the local audio speaker output volume.
-outvol
(1 to 100)
Set the audio outgoing volume.
-compression
compressiontype
Specify the type of compression to use. compressiontype can be
None, CellB, or HDSGrey.
-large
Set the initial Outgoing Image Resolution to 320x240.
-connector connector
Select the video input connector. connector can be either Composite
or SVideo.
-informat format
Select the video input signal format. format can be NTSC, PAL, or
SECAM.
-brightness (-30 to 30)
Set the initial video window brightness.
-contrast
(-30 to 30)
Set the initial video window contrast.
-saturation (-30 to 30)
Set the initial video window saturation.
-tint (-30 to 30)
Set the initial video window tint.
-indev audioinputdevice
Indicate the type of audio device attached to the ViewStation's
AUDIO IN con nector. It is better to save this value in the
ViewStation's Setup client or to set it in the ViewStation's
Configuration File. The audioinputdevice can be "Unspecified", "HDS
ViewCam", "HDS Headset", "CallPort Spkr/Mic", "HDS Microphone", "HDS
Tuner", "VCR", or "Line Level Audio". See the DESCRIPTION section for
more information.
-outdev audiooutputdevice
Indicate the type of audio device attached to the ViewStation's
AUDIO OUT con nector. It is better to save this value in the
ViewStation's Setup client or to set it in the ViewStation's
Configuration File. The audiooutputdevice can be "HDS Inter nal
Speaker", "External Speakers", "HDS Headset", or "CallPort Spkr/Mic".
See the DESCRIPTION section for more information.
-quality (0 to 100)
See the DESCRIPTION section for more information.
-mcast
address
Set the destination IP address. This can be a multicast or a
standard unicast IP address.
-vidport networkportnum
Specify the Internet TCP network port number to use for the video
connection. The default is 4444.
-audport
networkportnum
Specify the Internet TCP network port number to use for the audio
connection. The default is 4445.
-ttl
multicasttimetolive
Set the time-to-live for multicast packets.
-noaudio Don't use the ViewStation audio facilities.
This can be used to prevent conflicts with other audio programs.
X RESOURCES
In addition to the usual Xt and Motif resources, the
hdssimulcast program supports the following application- specific
resources. The values and defaults are the same as the corresponding
command line options.
HDSSimulcast.sendVid: Yes | No
HDSSimulcast.sendAud: Yes | No
HDSSimulcast.send: Yes | No
HDSSimulcast.localVolume: (0 to 100)
HDSSimulcast.outgoingVolume:
(1 to 100)
HDSSimulcast.compression: None | CellB | HDSGrey
HDSSimulcast.inputConnector:
connector
HDSSimulcast.inputFormat: format
HDSSimulcast.brightness:
(-30 to 30)
HDSSimulcast.contrast: (-30 to 30)
HDSSimulcast.saturation:
(-30 to 30)
HDSSimulcast.quality: (0 to 100)
HDSSimulcast.tint:
(-30 to 30)
HDSSimulcast.inputDevice: audioinputdevice
HDSSimulcast.outputDevice: audiooutputdevice
HDSSimulcast.mcastAddress:
networkportnum
HDSSimulcast.vidPort: networkportnum
HDSSimulcast.audPort:
networkportnum
HDSSimulcast.ttl: timetolive
HDSSimulcast.doAudio:
Yes | No
HDSconf.meterSafeColor: Pixel
HDSconf.meterWarningColor: Pixel
COPYRIGHT
Copyright 1995, HDS Network Systems, Inc.
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© 1996 by HDS Network Systems
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