Crystal Vision
Statesman
TANDEM 3G User Manual R1.4
50
23/04/2012
Audio Status and Control
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 it 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.
Invert
Each of the 32 audio input channels can be individually inverted by selecting invert in the de-
embedder input audio control area and AES input audio control area.
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.
Audio Resampling
The Resample Enable control affects how the audio data is manipulated to change the PCM
delays. On resampled channels (resample enabled) the audio will be continuously resampled
allowing seamless changes in audio delay. On non-resampled channels (resample not enabled)
samples will be passed unchanged through the signal path: if the delay has to change, single
audio samples will be dropped or repeated as required. This control has no effect on channels
containing Dolby E.
