All of lore.kernel.org
 help / color / mirror / Atom feed
From: Alan Young <Alan.Young@IEE.org>
To: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>,
	Takashi Iwai <tiwai@suse.de>
Cc: Raymond Yau <superquad.vortex2@gmail.com>, alsa-devel@alsa-project.org
Subject: Re: Improving status timestamp accuracy
Date: Tue, 19 Jul 2016 16:33:54 +0100	[thread overview]
Message-ID: <578E4862.4050603@IEE.org> (raw)
In-Reply-To: <93b0b35f-5b8d-6ba3-c7db-fb534e66d31c@linux.intel.com>

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?

  reply	other threads:[~2016-07-19 15:33 UTC|newest]

Thread overview: 25+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-06-04  9:31 Improving status timestamp accuracy Alan Young
2016-06-04 10:17 ` Clemens Ladisch
2016-06-04 10:43   ` Alan Young
2016-06-04 15:59     ` Clemens Ladisch
2016-06-04 16:20       ` Alan Young
2016-06-05 16:27         ` Clemens Ladisch
2016-06-05 16:32           ` Alan Young
2016-06-05  1:14 ` Raymond Yau
2016-06-05 10:33   ` Alan Young
2016-06-06  1:24     ` Raymond Yau
2016-06-06  9:40       ` Alan Young
2016-06-06  8:34     ` Takashi Iwai
2016-06-06  9:42       ` Alan Young
2016-06-06 14:53         ` Pierre-Louis Bossart
2016-06-07  6:44           ` Alan Young
2016-06-07 18:01             ` Pierre-Louis Bossart
2016-07-08 15:03             ` Alan Young
2016-07-15 20:13               ` Pierre-Louis Bossart
2016-07-19 15:33                 ` Alan Young [this message]
2016-07-19 15:58                   ` Pierre-Louis Bossart
2016-07-20  6:59                     ` Alan Young
2016-08-01 21:56                       ` Pierre-Louis Bossart
2016-08-02  7:30                         ` Alan Young
2016-08-02  7:55                           ` Clemens Ladisch
2016-08-02 16:25                           ` Pierre-Louis Bossart

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=578E4862.4050603@IEE.org \
    --to=alan.young@iee.org \
    --cc=alsa-devel@alsa-project.org \
    --cc=pierre-louis.bossart@linux.intel.com \
    --cc=superquad.vortex2@gmail.com \
    --cc=tiwai@suse.de \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.