Cisco D9054 Installation And Operation Manual page 141

Setting Up the Dolby Digital Audio Input,
7. Select the Sample Rate of the signal.
Set the sampling rate to 32, 44.1 or 48 kHz.
Note: You must select 48 kHz if the Passthrough of Dolby Digital is enabled.
Note: There is no advantage to increasing the encoding sample rate above that
of the input sample rate.
Note: For the lowest audio bit rates it is often recommended to use the lowest
sample rate for best quality.
8. Set the Data Rate of the signal.
Use this field to select the digital audio transmission rate. Settings for the
compressed bit rate are available from 56 to 640 kbit/s. Increasing the number in
this field increases the audio bandwidth at the encoder, improving the quality of
the audio transmitted by the encoder.
The default is 192 kbit/s.
Use the following data rate ranges for the selected audio mode.
Stereo 2/0
Dual Mono 1+1
Mono (Center) 1/0
3/2 (L,R,C,Ls,Rs)
If the Passthrough of Dolby Digital/Dolby Digital Plus is enabled, it is
recommended that you set the maximum data rate to that of the external Dolby
Encoder. If the data rate of the Dolby Encoder is lower than the setting in the
D9054 HD Encoder the audio will be passed through and only the actual bits in
the data stream will be used.
Note: The external Dolby Encoder must be locked to the clock of the D9054 HD
Encoder. This can be achieved by connecting the Digital Output of the audio
connector to the external encoder.
Note: The 3/2 (L,R,C,Ls,Rs) mode is only available for encoders equipped with
a Multiple Channel Audio (MCA) card.
9. Set the PES Frame Count.
Use this field to set the desired number of audio frames in each PES packet. This
affects the number of stuffing bytes inserted in the encoded audio stream, but
has little affect on the encoding quality. The legal range is from 1 to 8. The
default value is 8.
4038938 Rev A
Mode
Dolby Digital
96 – 640 kbit/s
96 – 640 kbit/s
56 – 640 kbit/s
224 – 640 kbit/s
D9054 HDTV Encoder Intstallation and Operation Guide
Continued
Data Rate Range
Dolby Digital Plus
56 - 640 kbits/s 72 - 640 kbits/s
56 - 640 kbits/s 72 - 640 kbits/s
56 - 640 kbits/s 72 - 640 kbits/s
72 - 640 kbits/s 192 - 640 kbits/s
Transcode
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