[alsa-devel] Improving status timestamp accuracy

[Alan Young]

On 15/07/16 21:13, Pierre-Louis Bossart wrote:
> in update_delay() you apply a delta between the last timestamp and the 
> current one and modify the runtime->delay.
>
> Immediately after, in update_audio_tstamp() runtime->delay is used as 
> well to compute audio_frames which in turn is used to find the 
> audio_tstamp, on which another delta between current tstamp and last 
> timestamp is applied.
>
> Overall it looks like you are correcting twice for the same delay?
>
In update_audio_tstamp() it either usedruntime->delay, if 
runtime->audio_tstamp_config.report_delay is true, or applies a delta - 
not both.

> Even if this was correct, you would want to make sure the delta is 
> positive to keep audio timestamps monotonous. 

Hmm, maybe. In what circumstances could the delay ever be negative?