• Open Menu Close Menu
  • Apple
  • Shopping Bag
  • Apple
  • Mac
  • iPad
  • iPhone
  • Watch
  • TV
  • Music
  • Support
  • Search apple.com
  • Shopping Bag

Lists

Open Menu Close Menu
  • Terms and Conditions
  • Lists hosted on this site
  • Email the Postmaster
  • Tips for posting to public mailing lists
Re: AudioFileReadPackets cache policy
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: AudioFileReadPackets cache policy


  • Subject: Re: AudioFileReadPackets cache policy
  • From: William Stewart <email@hidden>
  • Date: Tue, 6 Jul 2010 14:25:18 -0700

On Jul 4, 2010, at 2:37 PM, White Hexagon wrote:

> Indeed, but at the time it was the only way I could get AMR playback to
> work, see:
> http://stackoverflow.com/questions/2866367/how-to-populate-audiostreambasicdescription-for-amr-playback
> https://devforums.apple.com/message/224563#224563

haven't seen these threads before, but the conclusion doesn't seem right to me. If you can file a bug report we would be happy to look at it

>
> So now that my buffer is disk based (which has some benefits in terms of
> being able to 'replay' within a larger buffer),  I'd still like to know
> more about the caching, and if it explains my current issues.

You would have to ask that to the lower levels of the OS (file system) - we aren't cacheing any data in AudioFile

Bill
>
>
> On 2010-07-02 20:58, William Stewart wrote:
>> This seems like a very strange thing to do... Why wouldn't you just write and read from a buffer?
>>
>> On Jul 2, 2010, at 1:53 AM, White Hexagon wrote:
>>
>>> So just to clarify some more.  I have one thread writing frames to a
>>> file, which loops back to the start, after a certain number of frames
>>> have been written, and overwrites the previous data.
>>>
>>> My playback thread is a few seconds behind the writing.  My impression
>>> is that the after the first loop/'rewind', the new file contents look
>>> correct (I 'synchronizeFile' between writes), but the playback AQ seems
>>> to be using stale data.
>>>
>>> Now I'm playing around with trying to restart the AQ, which is causing a
>>> glitch in my audio each time it has to be torn down and setup.  I'm also
>>> starting to suspect that this is still using cached data, maybe because
>>> the filename is the same?  Although I'm struggling a bit to test and
>>> confirm this.
>>>
>>> Does anyone have any ideas what might be going on please?
>>>
>>> On 2010-06-30 14:54, White Hexagon wrote:
>>>> Regarding parameter: 'inUseCache (Set to true to cache the data.
>>>> Otherwise, set to false.)'
>
> _______________________________________________
> Do not post admin requests to the list. They will be ignored.
> Coreaudio-api mailing list      (email@hidden)
> Help/Unsubscribe/Update your Subscription:
>
> This email sent to email@hidden

 _______________________________________________
Do not post admin requests to the list. They will be ignored.
Coreaudio-api mailing list      (email@hidden)
Help/Unsubscribe/Update your Subscription:

This email sent to email@hidden

References: 
 >Re: AudioFileReadPackets cache policy (From: White Hexagon <email@hidden>)
 >Re: AudioFileReadPackets cache policy (From: William Stewart <email@hidden>)
 >Re: AudioFileReadPackets cache policy (From: White Hexagon <email@hidden>)

  • Prev by Date: QuickTime GM Synth for iPad?
  • Next by Date: Re: 2 AUCocoaView implementation questions: How to deal with uninitialized AU, and restrict Host to single view.
  • Previous by thread: Re: AudioFileReadPackets cache policy
  • Next by thread: mixer unit on iphone
  • Index(es):
    • Date
    • Thread