
GS1582 Data Sheet
40117 - 1 November 2007
41 of 114
NOTE: When serializing SDTI signals, it is recommended that the user ensure
there are no SMPTE 352M packets present in the input video data.
4.7.6 Audio Packet Multiplexing
The SD core places audio data packets contiguously after the EAV. Any Extended
Audio Data Packets are placed immediately following the Audio Data Packet of the
same audio group.
The HD core places audio data packets contiguously after the two line CRC words.
In cases where the SMPTE 352M packet or SDTI header are present after the EAV
or CRC, the audio data will be placed contiguously from the 352M or SDTI header
packets. On lines where the 352M or SDTI header packets are present, there may
be insufficient HANC space for embedding 4 audio groups. If there is insufficient
HANC space available, the 352M or SDTI header packets are always re-inserted
and the remaining audio group packet to be inserted is discarded.
On lines where the EDH packet is present, the audio data will be embedded up to
the point reserved for the EDH packet. If there is insufficient HANC space
available, the EDH packet is always re-inserted and the audio data packet
discarded.
In the case where there is insufficient room in the HANC space to embed the
selected audio data packets, the multiplexer core will delete any arbitrary data
packets. If there is still insufficient room in the HANC space, the multiplexer core
will not embed audio data packets.
4.7.7 Audio Insertion After Video Switching Point
4.7.7.1 SD Formats
The switching lines for SD formats are defined in SMPTE RP 168 as lines 10 and
273 for 525-line based formats, and lines 6 and 319 for 625-line based formats.
The audio core does not place any audio data or control packets in the line
immediately after the video switching line. For example, with the standard switch
point of line 10 for field 1 in 525, there will be no audio data or control packets on
line 11. The next packets will appear on line 12.
4.7.7.2 HD Formats
The video switching lines for HD formats are defined in SMPTE 299M as lines 7
and 569. The audio core does not place any audio data or control packets in the
line immediately after the video switching point. For example, with the standard
switch point of line 7 for field 1, there will be no audio data packets in line 8. The
next packets will appear on line 9. The audio control packets will be multiplexed
once per field, two lines after the video switch point, on lines 9 and 571.