• 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: Getting packets from ima4 file
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: Getting packets from ima4 file

  • Subject: Re: Getting packets from ima4 file
  • From: Kevin Dixon <email@hidden>
  • Date: Wed, 13 May 2015 22:16:53 -0700
You might want to check the specification for this format

https://developer.apple.com/library/mac/documentation/MusicAudio/Reference/CAFSpec/CAFSpec.pdf

I didn't read it, but it looks like it should get you started

Kevin

On Tue, May 12, 2015 at 12:29 AM, Brian Willoughby <email@hidden> wrote:
As far as I know, CoreAudio is not open source.

afconvert is based on CoreAudio. While you can obtain the source to afconvert easily as part of Apple developer tools, you won't be able to run the code anywhere except OSX and iOS because of the API that it uses extensively.

If you want to learn more, search for API such as AudioConverter, AUConverter, and particularly ExtAudioFile. With ExtAudioFile, a CoreAudio application can open any audio file format (except FLAC, unless you write a plugin), convert it to PCM, and then write it out to any format. As long as you're writing a CoreAudio program, there's probably nothing easier than ExtAudioFile.

As for the internals of ExtAudioFile, I've never gone looking for the source code in Apple's various open source collections. It might be there, but if it is then I don't know about it. If anyone else knows otherwise, I'm sure they'll pipe up.

Brian


On May 11, 2015, at 10:01 AM, Arun Balaji Prithivi Raj <email@hidden> wrote:
> Thank you Brian for your prompt response.
>
> I want to know the internals of the command afconvert. How they are reading audio file and storing in form of packets.
>
> On May 11, 2015 12:32 PM, "Brian Willoughby" <email@hidden> wrote:
>> Apple provides "afconvert" - a command-line utility that uses CoreAudio to convert any supported file. You could easily batch-convert all of your IMA4 files to AIFF or RIFF/WAVE.
>>
>> On May 10, 2015, at 7:54 PM, Arun Balaji Prithivi Raj <email@hidden> wrote:
>>> I am an android developer. I want to convert the ima4 audio file to pcm file using Java. I knew the conversion logics to do. But before that how to convert ima4 to packets in java. Could you please put some light on this topic so that I can benefit from that.


 _______________________________________________
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: 
 >Getting packets from ima4 file (From: Arun Balaji Prithivi Raj <email@hidden>)
 >Re: Getting packets from ima4 file (From: Chris Adamson <email@hidden>)
 >Re: Getting packets from ima4 file (From: Brian Willoughby <email@hidden>)
 >Re: Getting packets from ima4 file (From: Brian Willoughby <email@hidden>)

  • Prev by Date: resetting audio engine after NaN in audio buffer
  • Next by Date: Use AudioQueue or AudioUnits?
  • Previous by thread: Re: Getting packets from ima4 file
  • Next by thread: NULL pointer value for device name when compiling with no "-arch i386"
  • Index(es):
    • Date
    • Thread