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IQBRK00/01
B12
IQBRK00OPS 05/04/07
www.snellwilcox.com
Version 1 Issue 6
B12.79
Appendix 2 HANC & Embedding
HANC Data Handling and Embedding Functionality
Audio Embedding Packet Distribution
625
Lines 5, 7, 318, 320
Have
no introduced samples on them
Lines 4, 6, 9,10, 11,13, 26, 39, 52, 65, 78, 91, 104, 117, 130, 143, 156, 169, 182, 195, 208, 221, 234, 247,
260, 273, 286, 299, 317, 319, 322, 323, 324, 325, 338, 351, 364, 377, 390, 403, 416, 429, 442, 455, 468, 481,
494, 507, 520, 533, 546, 559, 572, 585, 598, 611, 624
Have four introduced samples on them
All other lines have three samples
525
Lines 9, 11, 272, 274
Have no introduced samples on them.
Lines 3, 10, 33, 48, 78, 83, 108, 123, 138, 153, 168, 183, 198, 213, 228, 243, 258, 265, 273, 288, 303, 318,
333, 348, 363, 378, 393, 408, 423, 408, 438, 453, 468, 483, 498, 513
Line 18 has either 3 sample for frames 2 and 4 or 4 samples for frames 1, 3 or 5
All other lines have three samples.
Firewall See Appendix 1
Hanc
Blanking Control.
When
“Hank Blank” is enabled the HANC space is cleared of all incoming packets. In this case the non-PCM
and non-audio data is removed. If pass HANC control is disabled then the incoming non-audio packets are
inserted following the packets created by this unit. Bypassing will leave all non-audio packets intact. Any audio
group that is to be embedded; will remove any packet from the incoming stream from the same group.
HANC Overflow Condition
The card assumes that the incoming HANC is SMTE291 compliant. If there is data embedded in the HANC
space that is non-compliant then it would be outside of the unit’s handling capability.
Alternate HANC Packet Specification
Only audio packet types are validated and with the exception of packets that are of the “Marked for
deletion” type, all packets are passed as they are.
“Marked for deletion packets” are removed if they can be while maintaining continuity. Checksum calculation is
done on generated packets but not on passed through packets.
If an audio packet has gone through the bypass process then the packet is not changed. If the audio has been
processed and embedded then packet parity is calculated for the generated packets.
If pre-existing embedded audio is not valid due to not having enough samples then in bypass mode
the same data is passed to the output. If this type of broken input is extracted then the unit will try to sample
rate convert (SRC) to the correct 48kHz sample rate. The SRC’d drops or holds will be more or less audible
depending on how broken the incoming audio packets are.
Recognize Audio Data Packet Identifiers
Recognize:(DID)
2FF
1FD
1FB
2F9
Audio Group
1FE
2FC
2FA
1F8
Extended Audio
1EF
2EE
2ED
1EC
Control Packet