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From: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
To: Clemens Ladisch <clemens@ladisch.de>
Cc: alsa-devel@alsa-project.org
Subject: Re: [PATCH 1/2] ALSA: core: add hooks for audio timestamps
Date: Sat, 29 Sep 2012 15:17:31 -0500	[thread overview]
Message-ID: <5067575B.8070500@linux.intel.com> (raw)
In-Reply-To: <50656EFE.40407@ladisch.de>


>> +				audio_frames = runtime->status->hw_ptr
>> +					+ runtime->delay;
>> +			audio_nsecs = audio_frames * 1000000000LL /
>> +				runtime->rate;
>
> This looks like a 64-bit division.
>
> And what happens if audio_frames becomes negative?

It's my understanding that hw_ptr represents the cumulative frames 
played since the beginning, not sure why it'd become negative, ever.
I know this deserves more love, I don't understand the notion of 
'boundary' and the use of the hw_ptr_base, I figured smarter people than 
me would help.
Thanks,
-Pierre

  reply	other threads:[~2012-09-29 20:17 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-09-28  8:15 [PATCH 1/2] ALSA: core: add hooks for audio timestamps Pierre-Louis Bossart
2012-09-28  8:15 ` [PATCH 2/2] ALSA: hda: support for wallclock timestamps Pierre-Louis Bossart
2012-09-28  9:33   ` Clemens Ladisch
2012-09-29 20:12     ` Pierre-Louis Bossart
2012-09-30 10:12       ` Clemens Ladisch
2012-09-29  1:47   ` Raymond Yau
2012-09-28  9:33 ` [PATCH 1/2] ALSA: core: add hooks for audio timestamps Clemens Ladisch
2012-09-29 20:17   ` Pierre-Louis Bossart [this message]
2012-09-30 10:11     ` Clemens Ladisch

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