Hello Clemens
On 12/01/2016 04:15 AM, Clemens Ladisch wrote:
Jiada Wang wrote:
On 11/30/2016 11:41 PM, Clemens Ladisch wrote:
Jiada Wang wrote:
since commit 57e6dae1087bbaa6b33d3dd8a8e90b63888939a3 the expected packetsize is always limited to
nominal + 25%. It was discovered, that some devices
Which devices?
It was a LG nexus
So it was the Android audio accessory mode.
have a much higher jitter in used packetsizes than 25%
How high?
the nominal packet size was somewhere around 176bytes
+25% would result in max expected packets to be ~220bytes
We observed some packets exceeding this size (256byte)
256 bytes per USB frame would correspond to 64 kHz, instead of the
nominal 44.1 kHz.
The audio accessory sample format is fixed, and that mode is no longer
developed, so increasing the limit to +50% would be sufficient to work
around this problem.
I don't know if this is a bug in Google's generic AOA code, or if LG did
some changes; I have not heard any other report so far ...
We also reproduced the same issue with following android devices,
* Samsung S4, Android 4.2.2, model GT-I9505
* Sony Xperia Z, Android 4.2.2, model number CC6603
* LGE Nexus 4, Android 4.2.2
so it most likely not a LG specific issue.
I agree to increase to +50% would be sufficient to avoid this issue.
Thanks,
Jiada
Regards,
Clemens
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