iOS Question New AudioRecorder on iMedia library

[Giuliano Cucchiarini]

Hi

I noticed that now the iMedia library has also an AudioRecorder.

In the documentation for the Initialize there is written:

Initialize(Dir As String, FileName As String, SampleRate As Int, Mono As Boolean, Encoding As Int, MPEG4 As Boolean)

What is 'Encoding as int'? I could not find any explanation in the documentation.

Thank you

Giuliano C.

 

[Erel]

It is missing by mistake. It should be either 8 for 8 bit encoding or 16 for 16 bit encoding.

 

[daniel69]

Is there any way to read the microphone buffer? Actually in B4A I use the AudioStreamer (I get the buffer content with the RecordBuffer event and there is no need to save the data on a file)

 

[Erel]

No. You will need to write it to a temporary file.

 

[daniel69]

Hi Erel, thank you for you reply! I've got to port to iOS an app that uses the mic data in real time ... write and read on a file I think it will come out to be too slow .. I've got less than 10 milliseconds to read the data, process it (heavy calculations with FFT and some digital filters) , and display the info on a graph... Any way out? Any way to to use the audiounit iOS API from B4i? Maybe using an objective-c class with nativeobject?

 

[Erel]

It will not be easier than writing a library for this (complicated) API.

 

[daniel69]

Thaks Erel ... When I start the porting I'll try to write the mic buffer to a temporary file ... I'll try to record a PCM file from the mic for some milliseconds (using audiorecorder in imedia library and a timer ) and then read it using the OpenInput inputstream (by the way, are PCM bytes saved in littleEndian or bigEndian ?) and process it ...

 

[Erel]

are PCM bytes saved in littleEndian or bigEndian

I haven't checked it, but based on the documentation I think that it is little endian.

 

[daniel69]

Hi Erel! Any news about reading the microphone buffer? Now I still have to read a temporary file (slow processing) ...

 

[Erel]

AudioRecorder is based on AVAudioRecorder API. It only allows saving the data to a file.

https://developer.apple.com/library...ence/#//apple_ref/doc/uid/TP40008238-CH1-SW14

 

[tigrot]

I'm starting to write a library for this use. Let me know you needs, so I'll do the work only one time.

 

[joop]

@tigrot

I am also very interested in this library :
- write the mic to a buffer
- do something with the data in this buffer
- send this buffer to the speaker.

Joop

 

[daniel69]

Hi @tigrot .... sorry for the delay ... I've been busy ... my requirement is to read the audio buffer in the same way that is possible in Android with the AudioStreamer library ...

 

[tigrot]

Hi Daniel69, I'm busy at this time with one finalised project and one going alive in a few days. Audio for Iphone is not a priority for me at present. Maybe in late summer...

 

[daniel69]

Hi @tigrot ! Thank you for your reply ... I'll stay in contact for any news ...

 

[daniel69]

Hi @tigrot ! Any news? Let me know if you dropped this project ...

 

[daniel69]

Hi @tigrot ! Any news? Let me know if you dropped this project ...