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Note:
This block is present only if a valid video signal is available on the selected port.
4.5.5.3. Audio info block
Page 58 / 109
Legend: 1920x1080 resolution in progressive mode at 50Hz vertical
refresh value, YUV444 color space. The frequency of the horizontal
sync is 270kHz.
Format: Aabcdeeff
The audio info block determines the type of the audio, the decoded
sampling frequency and some further information extracted from Audio
InfoFrames.
The system is able to distinguish three main audio types: LPCM audio,
compressed audio and high-bitrate audio. LPCM audio (also called
Linear Pulse Code Modulation) can be 2-channel or multichannel with
various sample lengths and sampling frequencies. The compressed
audio means an IEC61937 compliant stream, which could be for
example Dolby Digital, DTS or MLP. The system is not able to
distinguish these compressed formats. The High-Bit-Rate (HBR) audio
means the new formats that were defined in the HDMI 1.3 specification
such as Dolby TrueHD and DTS-HD Master Audio.
The first character shall be 'A', this identifies the type of the block. The
following characters have different meanings:
a:
'0' - There is no audio data present on this link. The following
characters will be missing in the block.
'1' - PCM audio
'2' - Compressed audio
'4' - High-Bit-Rate audio
b:
This field determines the sampling frequency decoded by the
built-in audio clock regeneration unit. The possible values are:
A
44.1 kHz
C
48 kHz
D
32 kHz
E
22.05 kHz
G
24 kHz
I
88.2 kHz
c:
This hexadecimal number determines the used audio codec.
This value is the same as the first four bits in the Audio
Infoframes. Please note that most of the DVD and BD players
don't specify this field.
The possible values according to the CEA-861 specification:
0
Undetermined
1
IEC60958PCM
2
AC-3
3
MPEG1 (Layers 1& 2)
4
MP3 (MPEG1 Layer 3)
5
MPEG2 (multichannel)
6
AAC
J
768 kHz
K
96 kHz
M
176.4 kHz
O
192 kHz
B
no information
7
DTS
8
ATRAC
9
One Bit Audio
A
Dolby Digital +
B
DTS-HD
C
MLP
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