Hd sdi, Audio decoding and output stage, General – TANDBERG High Definition Professional Recevier/Decoder TT1280 User Manual
Page 96: Mpeg audio, Dolby digital ac-3 audio, B.1.4, B.2.1, B.2.2, B.2.3, B.2 audio decoding and output stage
Technical Specification
Page B-4
Reference Guide: TT128x High Definition Professional Receiver/Decoder
ST.RE.E10141.5
B.1.4 HD
SDI
HD SDI output supports:
•
Embedded Decoded Audios
•
Closed Captioning (EIA 708B)
•
VITC
B.2
Audio Decoding and Output Stage
B.2.1 General
The IRD is capable of simultaneously decoding two PES streams of audio
from the transport stream. Each of the decoders is identical in operation,
but act completely independently of the other, with the following
exceptions:
•
Both decoders must be decoding channels that have the same
sampling rate
•
Both decoders are not required to simultaneously decode the same PES
stream
Each channel supports extraction of four types of coded audio from the
Transport Stream as follows:
•
MPEG-1, Layer 2 Audio (Musicam): ISO/IEC 13818-3
•
Dolby Digital AC-3 Audio: ATSC document A/52
•
Linear Audio: SMPTE 302M – 2000
•
DTS Audio pass-through
Audio component selection is automatic or may be specified from the User
Interface or remote interfaces. The IRD automatically detects the audio
type of the selected audio component and applies the appropriate
algorithm. Audio component selection is based on the position of the
component descriptor in the PMT. Audio 1 takes the first component,
Audio 2 the second. These may be overridden by selecting User-specified
component PIDs.
B.2.2 MPEG
Audio
The IRD supports decoding of MPEG audio as follows:
•
Compression layers: MPEG-1 layers I and II
•
Sampling rates (kHz): 32, 44.1, 48
•
Maximum compressed data rate: 384 kbit/s (layer II)
B.2.3
Dolby Digital AC-3 Audio
The IRD is able to decode and output the primary stereo pair of a Dolby
Digital AC-3 encoded audio stream. When there is data encoded on the
audio surround channels, the Decoder applies downmixing, so that either a
surround encoded stereo pair (LtRt downmix) or a conventional stereo pair
(LoRo downmix) is available at the output.
The IRD is not able to decode and output all 5.1 channels individually as
separate channels.