Crystal Vision
Card edge operation
TANDEM 3G User Manual R1.4
26
23/04/2012
Audio delay
These controls can be used to delay the audio with respect to the video by up to 80ms and
compensate for any small delay between the incoming video and audio signals. This audio
delay can be applied individually to each of the de-embedded groups and individual AES
stereo pairs by selecting them to be delayed or not delayed. The delay is applied at the output
of the router and is a single global control set in the audio delay menu.
Stereo to Mono conversion
For the purposes of this discussion it is assumed that all inputs are stereo pairs and that each
half of the stereo pair is on a consecutive input i.e. input 1 and input 2 are a stereo pair, input 3
and input 4 are a stereo pair, etc.
The action of converting a stereo pair to a mono output is simply a summing process followed
by a gain correction. The gain correction is necessary because when the two components of a
stereo signal are summed, a 6dB increase in output level will result; this will then need to be
corrected to maintain unity gain.
The action of selection will cause that channel to output the mono sum of itself and its
associated channel. The associated channel output will still output its unaltered programme.
Either channel of a pair can be selected for stereo to mono conversion.
Example: Selecting channel 1 for mono conversion will result in channel 1 outputting the
converted mono sum of channels 1 and 2. Channel 2 will remain outputting the original
channel 2 programme. Similarly deselecting channel 1 and selecting channel 2 will cause
channel 2 to output the converted mono programme and channel 1 the original channel 1
programme.
Note:
When transporting Dolby E, to ensure integrity of the audio any Dolby E stream must be
treated as a stereo pair and no audio processing such as mute, mono and gain is applied.
Invert and mute
Each of the 32 audio input channels can be individually inverted or muted by selecting mute
and invert in the de-embedder invert, AES invert, de-embedder mute and AES mute menus.
Note:
When routing Dolby E, to ensure integrity of the audio any Dolby E stream must be
treated as a stereo pair and no audio processing such as mute, mono and gain is applied.
Routing matrix
At the heart of TANDEM 3G is the twin 32 input/16 output routing matrix. This will
allow any of the up to 32 possible inputs, 16 embedded channels and up to eight stereo
AES audio inputs to be routed to any of the 16 outputs for embedding or up to eight stereo
AES outputs. The AES channels can be configured as either inputs or outputs from the
AES SETUP menu giving a total of eight stereo channels of mixed I/O.
Note:
All routing matrix changes are live so care should be taken when re-routing as all changes
in routing will appear on the output of the routing matrix instantaneously.
Embedder pattern
The embedders can be set to give either the Sony pattern or the SMPTE pattern.
