Hi While testing the audio driver using aplay in blocking mode, a periodic murmur is observed, this increases with the audio volume and occurs even when there are no issues like xrun etc. Aplay was used in normal read/write mode i.e. no mmap. The song can be heard properly i.e. with no noticable gaps aur hisses but the clicks are audible.
I have tried various combinations of period size and buffer size but the quality doesn't seem to improve. I checked the latency between to consecutive calls of snd_pcm_write in aplay and log is as follows.
I am having 16 periods of 1K size and from log it is seen that the latency is too much at the buffer boundary, i.e. higlighted and starred line in the logs. I think the clicks are caused due these huge delays since the clicks are also quite periodic. Any thoughts?
#aplay -Dhw:0,0 --rate=44100 --format=S16 --channels=2 --period-size=1024 --buffer-size=16384 Learning.wav
1 2 Latency = 0.000000 3 Latency = 0.001805 4 Latency = 0.000741 5 Latency = 0.000674 6 Latency = 0.000643 7 Latency = 0.000668 8 Latency = 0.000625 9 Latency = 0.000611 10 Latency = 0.000647 11 Latency = 0.000627 12 Latency = 0.000626 13 Latency = 0.000635 14 Latency = 0.000631 15 Latency = 0.000616 16 Latency = 0.000645 17 Latency = 0.000634 18 Latency = 0.000958 19 Avg Latency is => 0.000737 20 21 Latency = 0.371909 /********Too much latency***********/ 22 Latency = 0.000767 23 Latency = 0.000701 24 Latency = 0.000696 25 Latency = 0.000657 26 Latency = 0.000677 27 Latency = 0.000667 28 Latency = 0.000673 29 Latency = 0.000674 30 Latency = 0.000627 31 Latency = 0.000675 32 Latency = 0.000880 33 Latency = 0.000726 34 Latency = 0.000682 35 Latency = 0.000705 Latency = 0.000648 37 Avg Latency is => 0.023898 38 39 Latency = 0.361167 /********Too much latency***********/ 40 Latency = 0.000744 41 Latency = 0.000692 42 Latency = 0.000678 43 Latency = 0.000672 44 Latency = 0.000637 45 Latency = 0.000696 46 Latency = 0.000668 47 Latency = 0.000674 48 Latency = 0.000885 49 Latency = 0.000710 50 Latency = 0.000670 51 Latency = 0.000663 52 Latency = 0.000654 53 Latency = 0.000667 54 Latency = 0.000676 55 Avg Latency is => 0.023222 56 57 Latency = 0.361260 /********Too much latency***********/ 58 Latency = 0.000710 59 Latency = 0.000703 60 Latency = 0.000685 61 Latency = 0.000671 62 Latency = 0.000665 63 Latency = 0.000796 64 Latency = 0.000714 65 Latency = 0.000692 66 Latency = 0.000704 67 Latency = 0.000695
-Pharaoh