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Source
Select the AV source, if any, to be used with your channel. No AV source is necessary if the HTML5
presentation is full screen media.
Resolution
Select the video resolution for your encoded TV channel. Lower resolutions consumer fewer system
resources. 1280x720 is a good default HD setting for most systems. Systems with a single encode can
easily perform higher resolutions. The resolutions you choose should be compatible with your
international DTV standard.
Frame Rate
720P30 and 720P29.97 are a good default HD settings (30 and 29.97 fps respectfully). Higher rates are
possible but not recommended when using multiple encoders on the same system.
Codec
Choose the codec that is compatible with your international DTV standard. ATSC requires MPEG2.
Bitrate
Typically auto is the best selection for bitrate. This allows the encoder to make quality and bitrate
adjustments based upon content. If a constant bitrate is required for your application, keep in mind
that a low setting will impact video quality.
Fixed data rate encoding is enabled by specifying a “Bitrate”. This bitrate is specified in Kbps and it sets
only the video encoder datarate, not the audio data rate or the TS output data rate. When setting this,
keep in mind that the audio encoding and transport stream overhead is 500 – 600 Kbps. Setting an
encoding to 900 Kbps will result in a 1500 Kbps transport stream. If this encoding is used in a low bitrate
IP transport output, care should be given to ensure that the encoded data rate is less than the output
data rate. This can be monitored on the Output tab of the Overview web page. The upper right corner
shows the overall bitrate of the output and an error will be shown if there is insufficient bandwidth in
the output transport. If more bandwidth is needed, edit the IP Output and increase the data rate. IP
transport outputs can also be configured to conserve bandwidth by setting the “Strip NUL’s” option.
This option will strip the null packets from the output transport stream.
Overscan
Overscan adjustments are necessary when applying graphics on TV displays. TVs will often overscan the
video thus clipping a few pixels on all side. To adjust for this the MX-400 encoder will scale the image to
fit on a slightly smaller screen and paint the outside pixels black. When rendered on the TV, the entire
image is visible. Typically a value of 3 – 5% is suitable. However overscan adjustment is not necessary if
all the TVs are configure with overscan disabled.
Audio Gain
Audio gain will increase the volume or decrease the volume during encoding. Acceptable values are -10
to 10.
