adding debug logs. I don't see any problem
with the logs below but still I can see in the
recorded data there are missing frames or
corruption.
# cat /proc/asound/Loopback/cable#0
Cable 0 substream 0:
valid: 3
running: 3
pause: 0
Playback
buffer_size: 96000
buffer_pos: 72576
silent_size: 0
period_size: 24000
bytes_per_sec: 192000
sample_align: 4
rate_shift: 100000
update_pending: 0
irq_pos: 576000
period_frac: 24000000
last_jiffies: 4613492552 (4613492610)
timer_expires: 4613492674
Capture
buffer_size: 96000
buffer_pos: 73152
silent_size: 0
period_size: 24000
bytes_per_sec: 192000
sample_align: 4
rate_shift: 100000
update_pending: 0
irq_pos: 1152000
period_frac: 24000000
last_jiffies: 4613492552 (4613492610)
timer_expires: 4613492671
Cable 0 substream 1:
inactive
Cable 0 substream 2:
inactive
Cable 0 substream 3:
inactive
Cable 0 substream 4:
inactive
Cable 0 substream 5:
inactive
Cable 0 substream 6:
inactive
Cable 0 substream 7:
inactive
# cat /proc/asound/Loopback/cable#0
Cable 0 substream 0:
valid: 3
running: 3
pause: 0
Playback
buffer_size: 96000
buffer_pos: 48768
silent_size: 0
period_size: 24000
bytes_per_sec: 192000
sample_align: 4
rate_shift: 100000
update_pending: 0
irq_pos: 768000
period_frac: 24000000
last_jiffies: 4613494928 (4613495026)
timer_expires: 4613495049
Capture
buffer_size: 96000
buffer_pos: 49344
silent_size: 0
period_size: 24000
bytes_per_sec: 192000
sample_align: 4
rate_shift: 100000
update_pending: 0
irq_pos: 1344000
period_frac: 24000000
last_jiffies: 4613494928 (4613495026)
timer_expires: 4613495046
Cable 0 substream 1:
inactive
Cable 0 substream 2:
inactive
Cable 0 substream 3:
inactive
Cable 0 substream 4:
inactive
Cable 0 substream 5:
inactive
Cable 0 substream 6:
inactive
Cable 0 substream 7:
inactive
# cat /proc/asound/Loopback/cable#0
Cable 0 substream 0:
valid: 3
running: 3
pause: 0
Playback
buffer_size: 96000
buffer_pos: 48768
silent_size: 0
period_size: 24000
bytes_per_sec: 192000
sample_align: 4
rate_shift: 100000
update_pending: 0
irq_pos: 768000
period_frac: 24000000
last_jiffies: 4613495928 (4613495963)
timer_expires: 4613496049
Capture
buffer_size: 96000
buffer_pos: 49344
silent_size: 0
period_size: 24000
bytes_per_sec: 192000
sample_align: 4
rate_shift: 100000
update_pending: 0
irq_pos: 1344000
period_frac: 24000000
last_jiffies: 4613495928 (4613495963)
timer_expires: 4613496046
Cable 0 substream 1:
inactive
Cable 0 substream 2:
inactive
Cable 0 substream 3:
inactive
Cable 0 substream 4:
inactive
Cable 0 substream 5:
inactive
Cable 0 substream 6:
inactive
Cable 0 substream 7:
inactive
# cat /proc/asound/Loopback/cable#0
Cable 0 substream 0:
valid: 3
running: 3
pause: 0
Playback
buffer_size: 96000
buffer_pos: 1152
silent_size: 0
period_size: 24000
bytes_per_sec: 192000
sample_align: 4
rate_shift: 100000
update_pending: 0
irq_pos: 1152000
period_frac: 24000000
last_jiffies: 4613496680 (4613496783)
timer_expires: 4613496799
Capture
buffer_size: 96000
buffer_pos: 1728
silent_size: 0
period_size: 24000
bytes_per_sec: 192000
sample_align: 4
rate_shift: 100000
update_pending: 0
irq_pos: 1728000
period_frac: 24000000
last_jiffies: 4613496680 (4613496783)
timer_expires: 4613496796
Cable 0 substream 1:
inactive
Cable 0 substream 2:
inactive
Cable 0 substream 3:
inactive
Cable 0 substream 4:
inactive
Cable 0 substream 5:
inactive
Cable 0 substream 6:
inactive
Cable 0 substream 7:
inactive
# cat /proc/asound/Loopback/cable#0
Cable 0 substream 0:
valid: 3
running: 3
pause: 0
Playback
buffer_size: 96000
buffer_pos: 72576
silent_size: 0
period_size: 24000
bytes_per_sec: 192000
sample_align: 4
rate_shift: 100000
update_pending: 0
irq_pos: 576000
period_frac: 24000000
last_jiffies: 4613497552 (4613497610)
timer_expires: 4613497674
Capture
buffer_size: 96000
buffer_pos: 73152
silent_size: 0
period_size: 24000
bytes_per_sec: 192000
sample_align: 4
rate_shift: 100000
update_pending: 0
irq_pos: 1152000
period_frac: 24000000
last_jiffies: 4613497552 (4613497610)
timer_expires: 4613497671
Cable 0 substream 1:
inactive
Cable 0 substream 2:
inactive
Cable 0 substream 3:
inactive
Cable 0 substream 4:
inactive
Cable 0 substream 5:
inactive
Cable 0 substream 6:
inactive
Cable 0 substream 7:
inactive
# cat /proc/asound/Loopback/cable#0
Cable 0 substream 0:
valid: 3
running: 3
pause: 0
Playback
buffer_size: 96000
buffer_pos: 49536
silent_size: 0
period_size: 24000
bytes_per_sec: 192000
sample_align: 4
rate_shift: 100000
update_pending: 0
irq_pos: 1536000
period_frac: 24000000
last_jiffies: 4613498432 (4613498501)
timer_expires: 4613498549
Capture
buffer_size: 96000
buffer_pos: 50112
silent_size: 0
period_size: 24000
bytes_per_sec: 192000
sample_align: 4
rate_shift: 100000
update_pending: 0
irq_pos: 2112000
period_frac: 24000000
last_jiffies: 4613498432 (4613498501)
timer_expires: 4613498546
Cable 0 substream 1:
inactive
Cable 0 substream 2:
inactive
Cable 0 substream 3:
inactive
Cable 0 substream 4:
inactive
Cable 0 substream 5:
inactive
Cable 0 substream 6:
inactive
Cable 0 substream 7:
inactive
# cat /proc/asound/Loopback/cable#0
Cable 0 substream 0:
valid: 3
running: 3
pause: 0
Playback
buffer_size: 96000
buffer_pos: 25152
silent_size: 0
period_size: 24000
bytes_per_sec: 192000
sample_align: 4
rate_shift: 100000
update_pending: 0
irq_pos: 1152000
period_frac: 24000000
last_jiffies: 4613499305 (4613499373)
timer_expires: 4613499424
Capture
buffer_size: 96000
buffer_pos: 25728
silent_size: 0
period_size: 24000
bytes_per_sec: 192000
sample_align: 4
rate_shift: 100000
update_pending: 0
irq_pos: 1728000
period_frac: 24000000
last_jiffies: 4613499305 (4613499373)
timer_expires: 4613499421
Cable 0 substream 1:
inactive
Cable 0 substream 2:
inactive
Cable 0 substream 3:
inactive
Cable 0 substream 4:
inactive
Cable 0 substream 5:
inactive
Cable 0 substream 6:
inactive
Cable 0 substream 7:
inactive
# cat /proc/asound/Loopback/cable#0
Cable 0 substream 0:
valid: 3
running: 3
pause: 0
Playback
buffer_size: 96000
buffer_pos: 384
silent_size: 0
period_size: 24000
bytes_per_sec: 192000
sample_align: 4
rate_shift: 100000
update_pending: 0
irq_pos: 384000
period_frac: 24000000
last_jiffies: 4613500176 (4613500195)
timer_expires: 4613500299
Capture
buffer_size: 96000
buffer_pos: 960
silent_size: 0
period_size: 24000
bytes_per_sec: 192000
sample_align: 4
rate_shift: 100000
update_pending: 0
irq_pos: 960000
period_frac: 24000000
last_jiffies: 4613500176 (4613500195)
timer_expires: 4613500296
Cable 0 substream 1:
inactive
Cable 0 substream 2:
inactive
Cable 0 substream 3:
inactive
Cable 0 substream 4:
inactive
Cable 0 substream 5:
inactive
Cable 0 substream 6:
inactive
Cable 0 substream 7:
inactive
# cat /proc/asound/Loopback/cable#0
Cable 0 substream 0:
valid: 3
running: 3
pause: 0
Playback
buffer_size: 96000
buffer_pos: 48768
silent_size: 0
period_size: 24000
bytes_per_sec: 192000
sample_align: 4
rate_shift: 100000
update_pending: 0
irq_pos: 768000
period_frac: 24000000
last_jiffies: 4613500928 (4613500964)
timer_expires: 4613501049
Capture
buffer_size: 96000
buffer_pos: 49344
silent_size: 0
period_size: 24000
bytes_per_sec: 192000
sample_align: 4
rate_shift: 100000
update_pending: 0
irq_pos: 1344000
period_frac: 24000000
last_jiffies: 4613500928 (4613500964)
timer_expires: 4613501046
Cable 0 substream 1:
inactive
Cable 0 substream 2:
inactive
Cable 0 substream 3:
inactive
Cable 0 substream 4:
inactive
Cable 0 substream 5:
inactive
Cable 0 substream 6:
inactive
Cable 0 substream 7:
inactive
On Fri, Jun 14, 2024 at 7:50 PM noman pouigt <variksla@xxxxxxxxx> wrote:
>
> Hello Folks,
>
> I wanted to use aloop driver to dump playback
> audio data to a file in userspace for debugging
> without data being sent to hardware (just as a
> debug feature for future use).
>
> Command flow is this:
> 1. aloop capture device is started using below command
> first: "arec -D hw:0,1 /data/rec.wav &"
>
> 2. using aplay, userspace sends the playback data.
> "aplay -D hw:0,0 /data/test.wav"
>
> Using jiffies. Wondering if changing rate_shift
> (don't know what is that for) will help?
>
> However, even in this simple setup I can see aloop driver
> is corrupting the data and sinetone sent from playback
> has glitches. I have tried different period sizes as well
> but nothing worked. Wondering if this is by design i.e.
> if the aloop driver shouldn't be used for this purpose?
> Any debug steps will be highly appreciated.
>
> Thanks for your help,
