pcm « audio « iPhone iPad Media Q&A

1. How to record something other than Linear PCM on iPhone    stackoverflow.com

I'm having a hard time trying to record something other than linear PCM on the iPhone :-( The samples I've found (SDK's SpeakHere, Zdziarski's and Sadun's books and the one at trailsinthesand.com) ...

2. iPhone - get duration of linear PCM audio file    stackoverflow.com

I have a linear PCM file (.wav) in my app and I would like to get it's duration programatically. I could find the following using AudioStreamBasicDescription but could not make out ...

3. iPhone - how to measure amplitude of a PCM coded signal    stackoverflow.com

here's my problem at hand:

1. I need to analyze audio data in realtime to find out the amplitude of the signal
2. I can't use the AudioQueue metering functionality because it has too much ...

4. Is there a "simple" way to play linear PCM audio on the iPhone?    stackoverflow.com

I'm making a media playback app which gets given uncompressed linear PCM (über raw) audio from a third-party decoder, but I'm going crazy when it comes to just playing back the ...

5. What Are Linear PCM Values    stackoverflow.com

I am working with audio in the iPhone OS and am a bit confused. I am currently getting input from my audio buffer in the form of pcm values ranging from -32767 ...

6. Extracting Amplitude Data from Linear PCM on the iPhone    stackoverflow.com

I'm having difficulty extracting amplitude data from linear PCM on the iPhone stored in a audio.caf. My questions are:

1. Linear PCM stores amplitude samples as 16-bit values. Is this correct?
2. How is amplitude stored ...

7. iPhone Extended Audio File Services, mp3 -> PCM -> mp3    stackoverflow.com

I would like to use the Core Audio extended audio file services framework to read a mp3 file, process it as a PCM, then write the modified file back as a ...

8. Extracting audio channel from Linear PCM    stackoverflow.com

I would like to extract a channel audio from the an LPCM raw file ie extract left and right channel of a stereo LPCM file. The LPCM is 16 bit depth,interleaved, ...

9. AudioConverterConvertBuffer problem with insz error    stackoverflow.com

I have a problem with the this function AudioConverterConvertBuffer. Basically I want to convert from this format

  _

streamFormat.mFormatFlags = kLinearPCMFormatFlagIsSignedInteger | kLinearPCMFormatFlagIsPacked |0 ;
  _streamFormat.mBitsPerChannel = 16;
  _streamFormat.mChannelsPerFrame ...

10. How to get the PCM vector values during the audio recording?    stackoverflow.com

I am trying to get the array of PCM data values from the audio that is being recorded by the microphone.. and then, send it to a server, but I am ...

11. iPhone Audio Queue sample rate question    stackoverflow.com

I am in the process of making a piece of pitch correction software for the iPhone. I am currently at the fun Audio Queue part and I have a few questions ...

12. ObjectAL audio streaming in iphone?    stackoverflow.com

I am using objectAL to stream PCM data, from the sample code i have tried or play the online CGI streaming data,

   ALSource *source = [[ALSource source] retain];

  ...

13. iPhone: Problems encoding 32KHz PCM to 96Kbit AAC using AudioConverterFillComplexBuffer    stackoverflow.com

Has anyone had success converting 32KHz PCM to 96Kbit AAC on iPhone/iOS? I can not get this to work correctly on any hardware device. The code I wrote only works correctly ...

14. PCM to WAV file    stackoverflow.com

I am using http://www.subfurther.com/blog/2010/12/13/from-ipod-library-to-pcm-samples-in-far-fewer-steps-than-were-previously-necessary/ to convert m4a file to caf, i was try to look in the setting of the export and didn't find way to convert it to wav ...

15. Mp3 from iPhone library convert to PCM?    stackoverflow.com

I need to read some audio file from the iPhone/iPod library and then pass it to a function to do some detection. I need to decode from MP3 to PCM in order ...