• 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: kExtAudioFileProperty_AudioFile property invalid on 10.4?
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: kExtAudioFileProperty_AudioFile property invalid on 10.4?


  • Subject: Re: kExtAudioFileProperty_AudioFile property invalid on 10.4?
  • From: "Stephen F. Booth" <email@hidden>
  • Date: Mon, 7 Apr 2008 14:57:02 -0700

Hi Bill,

I think you are mis understanding what the cookie is for.
You're right- I guess I am/was unclear on the concept. Unfortunately it isn't the first time!

When you are encoding (going from LPCM to a compressed format, say 'aac ') then you set up the encoding converter with a bunch of parameters, vbr, bit rate, etc. Then, as you write the file you *get* the cookie from the converter before you are finished writing the file out.

When you are decoding (going from a compressed format, say 'aac ' to LPCM), you get the cookie from the file and *set* it on the converter you are using to decode.

So, the cookie contains information from an encoding session that the decoder needs in order to decode the stream. It may not have any specific information about encoding settings, etc, as its primary job is to configure a decoder, not an encoder.

In that context, I don't understand why you would set magic cookie data on a converter you are using to encode.
Thanks for the explanation- things make much better sense now.

Stephen
_______________________________________________
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: 
 >kExtAudioFileProperty_AudioFile property invalid on 10.4? (From: "Stephen F. Booth" <email@hidden>)
 >Re: kExtAudioFileProperty_AudioFile property invalid on 10.4? (From: William Stewart <email@hidden>)

  • Prev by Date: Re: kExtAudioFileProperty_AudioFile property invalid on 10.4?
  • Next by Date: ExtAudioFileCreateNew creates 32-bit float aiffs when 16-bit signed int is requested
  • Previous by thread: Re: kExtAudioFileProperty_AudioFile property invalid on 10.4?
  • Next by thread: ExtAudioFileCreateNew creates 32-bit float aiffs when 16-bit signed int is requested
  • Index(es):
    • Date
    • Thread