ANC (Audio) panel 2a
2b
2c
The anc (audio) panel provides control
and configuration of the audio data
channels.
The SDI/HDSDI/3G SDI video transport
supports up to 16 audio channels, arranged in four groups of four channels each.
• Transport Mode (Ç)
The VN-Matrix system supports two audio transport modes:
Transparent — The compression engine streams the selected audio data
exactly as embedded in the SDI/HDSDI/3G SDI format, with no processing. This mode
can result in a high bit rate.
Stereo — The compression engine extracts a single stereo pair (two channels) of audio
data and packs it into the data stream.
• Channel pair selection (É)
Channel pair 1 — Selects group 1, channels 1 and 2.
Channel pair 2 — Selects group 1, channels 3 and 4.
Channel pair 3 — Selects group 2, channels 1 and 2.
Channel pair 4 — Selects group 2, channels 3 and 4.
Channel pair 5 — Selects group 3, channels 1 and 2.
Channel pair 6 — Selects group 3, channels 3 and 4.
Channel pair 7 — Selects group 4, channels 1 and 2
Channel pair 8 — Selects group 4, channels 3 and 4.
In Transparent mode, you can select from two to eight channel pairs; you cannot select
a single pair. In stereo mode, you can select only one channel pair.
The indicator to the right of the list showing each channel pair is green if that audio
group is present in the SDI source.
• Compression (î)
NOTE: The compression drop box is available only when the stereo
transport mode is selected.
Table 6. Audio Compression Selections and Associated Bit Rates
Compression
selection
Bits per
sample
Sample
rate
Bit rate,
1 channel
Bit rate,
stereo Comment
48 kHz
sampling
pack 24 bits 24 48,000 1,152,000 2,304,000 Native, no compression
pack 20 bits 20 48,000 960,000 1,920,000 Native, no compression
pack 16 bits 16 48,000 768,000 1,536,000 Bit depth decimation
decimate 2 16 24,000 384,000 768,000 Bit depth decimation, 0.5 sample rate
decimate 4 16 12,000 192,000 384,000 Bit depth decimation, 0.25 sample rate
VN-Matrix 325 Serial Digital Over IP CODEC • Operation 39