not all listeners are decoding all channels

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cccuser
Junior Member
Posts: 6
Joined: Wed Aug 11, 2021 7:28 pm

not all listeners are decoding all channels

Post by cccuser »

i am using 2 200 development kits.
i am using one as a talker and the second as the listener

i am using the avb reference design.

on the talker board i have configured it to have 4 talkers. on the board listener i have configured it to have 4 listeners.

on the talker board i have configured it to put out test data for audio samples where each sample contains the stream id and channel number, so i can debug why in this configuration the listener board doesnt always decode all the channels. as follows

int32_t test_sample[32]={0x10101010,
0x11111111,
0x12121212,
0x13131313,
0x14141414,
0x15151515,
0x16161616,
0x17171717,
0x20202020,
0x21212121,
0x22222222,
0x23232323,
0x24242424,
0x25252525,
0x26262626,
0x27272727,
0x30303030,
0x31313131,
0x32323232,
0x33333333,
0x34343434,
0x35353535,
0x36363636,
0x37373737,
0x40404040,
0x41414141,
0x42424242,
0x43434343,
0x44444444,
0x45454545,
0x46464646,
0x47474747,
};


in this configuration when i connected as follows.
talker 1 is connected to listener 1
talker 2 is connected to listener 2
talker 3 is connected to listener 3
talker 4 is connected to listener 4

on the listener board i noticed that on listener 1 i am recieving the correct test audio samples for all 8 channels. on listener 2-4,  i dont see channel 1 i see channel 0, 2-7
since i am trying to use the output channels as not 8 channels but 4 stereo pairs, this bug results in getting left data but not right data but only on streams 2-4. stream and only on channel 1, 0,3-7 are ok. and stream 1 0-7 are always correct.
i verified using wireshark that the avb packets in each stream are always correct. they have all channel data on all streams.

im at a loss to describe why this is happening.
in this configuration, the avb design is setup to use tdm buffering and i am wondering if there is a timing issue but cant explain why it would always only affect streams 2-4

from the test data above i never see 
0x212121, 0x313131 and 0x414141 these outputs are decoded as but only on stream 1. on streams 2-4 they are always 0. this maps to channel 1 on each stream.

any insights would be appreciated.