I'm trying to use a Low Pass Filter AU. I keep getting a kAudioUnitErr_FormatNotSupported (-10868) error when setting the stream format to the filter unit, but if I just use the Remote IO unit there's no error.
The stream format I'm using is (Updated):
myASBD.mSampleRate = hardwareSampleRate;
myASBD.mFormatID = kAudioFormatLinearPCM;
myASBD.mFormatFlags = kAudioFormatFlagIsSignedInteger;
myASBD.mBitsPerChannel = 8 * sizeof(float);
myASBD.mFramesPerPacket = 1;
myASBD.mChannelsPerFrame = 1;
myASBD.mBytesPerPacket = sizeof(float) * myASBD.mFramesPerPacket;
myASBD.mBytesPerFrame = sizeof(float) * myASBD.mChannelsPerFrame;
And I'm setting the filter stream like this:
// Sets input stream type to ASBD
setupErr = AudioUnitSetProperty(filterUnit, kAudioUnitProperty_StreamFormat, kAudioUnitScope_Input, 0, &myASBD, sizeof(myASBD));
NSLog(#"Filter in: %i", setupErr);
//NSAssert(setupErr == noErr, #"No ASBD on Finput");
//Sets output stream type to ASBD
setupErr = AudioUnitSetProperty(filterUnit, kAudioUnitProperty_StreamFormat, kAudioUnitScope_Output, 0, &myASBD, sizeof(myASBD));
NSLog(#"Filter out: %i", setupErr);
NSAssert(setupErr == noErr, #"No ASBD on Foutput");
The canonical format for iOS filter audio units is 8.24 fixed-point (linear PCM), which is 32 bits per channel, not 16.
what format is working wit the reverb unit??? I'm getting weird errors tryn to record a buffer....any news on this topic?
Try this for the canonical format.
size_t bytesPerSample = sizeof (AudioUnitSampleType); //Default is 4 bytes
myASBD.mSampleRate = hardwareSampleRate;
myASBD.mFormatID = kAudioFormatLinearPCM;
myASBD.mFormatFlags = kAudioFormatFlagsAudioUnitCanonical; //Canonical AU format
myASBD.mBytesPerPacket = bytesPerSample;
myASBD.mFramesPerPacket = 1;
myASBD.mBytesPerFrame = bytesPerSample;
myASBD.mChannelsPerFrame = 2; //Stereo
myASBD.mBitsPerChannel = 8 * bytesPerSample; //32bit integer
You will need to make sure all your AudioUnits ASBDs are configured uniformly.
If you are doing heavy audio processing, floats (supported in iOS5) is not a bad idea too.
size_t bytesPerSample = sizeof (float); //float is 4 bytes
myASBD.mSampleRate = hardwareSampleRate;
myASBD.mFormatID = kAudioFormatLinearPCM;
myASBD.mFormatFlags = kAudioFormatFlagIsFloat;
myASBD.mBytesPerPacket = bytesPerSample;
myASBD.mFramesPerPacket = 1;
myASBD.mBytesPerFrame = bytesPerSample;
myASBD.mChannelsPerFrame = 2;
myASBD.mBitsPerChannel = 8 * bytesPerSample; //32bit float
Related
I'm trying to play PCM stream data from server using AudioQueue.
PCM data format :
Sample rate = 48000, num of channel = 2, Bit per sample = 16
And, server is not streaming fixed bytes to client. (variable bytes.)
(ex : 30848, 128, 2764, ... bytes )
How to set ASBD ?
I don't know how to set mFramesPerPacket, mBytesPerFrame, mBytesPerPacket .
I have read Apple reference document, but there is no detailed descriptions.
Please give me any idea.
New added : Here, ASBD structure what I have setted. (language : Swift)
// Create ASBD structure & set properties.
var streamFormat = AudioStreamBasicDescription()
streamFormat.mSampleRate = 48000
streamFormat.mFormatID = kAudioFormatLinearPCM
streamFormat.mFormatFlags = kLinearPCMFormatFlagIsSignedInteger | kAudioFormatFlagIsPacked
streamFormat.mFramesPerPacket = 1
streamFormat.mChannelsPerFrame = 2
streamFormat.mBitsPerChannel = 16
streamFormat.mBytesPerFrame = (streamFormat.mBitsPerChannel / 8) * streamFormat.mChannelsPerFrame
streamFormat.mBytesPerPacket = streamFormat.mBytesPerFrame
streamFormat.mReserved = 0
// Create AudioQueue for playing PCM streaming data.
var err = AudioQueueNewOutput(&streamFormat, self.queueCallbackProc, nil, nil, nil, 0, &aq)
...
I have setted ASBD structure like the above.
AudioQueue play streamed PCM data very well for a few seconds,
but soon playing is stop. What can I do?
(still streaming, and queueing AudioQueue)
Please give me any idea.
ASBD is just a structure underneath defined like follows:
struct AudioStreamBasicDescription
{
Float64 mSampleRate;
AudioFormatID mFormatID;
AudioFormatFlags mFormatFlags;
UInt32 mBytesPerPacket;
UInt32 mFramesPerPacket;
UInt32 mBytesPerFrame;
UInt32 mChannelsPerFrame;
UInt32 mBitsPerChannel;
UInt32 mReserved;
};
typedef struct AudioStreamBasicDescription AudioStreamBasicDescription;
You may set the variables of a struct like this:
AudioStreamBasicDescription streamFormat;
streamFormat.mFormatID = kAudioFormatLinearPCM;
streamFormat.mFormatFlags = kAudioFormatFlagIsSignedInteger | kAudioFormatFlagsNativeEndian | kAudioFormatFlagIsPacked;
streamFormat.mSampleRate = sampleRate;
streamFormat.mBitsPerChannel = bitsPerChannel;
streamFormat.mChannelsPerFrame = channelsPerFrame;
streamFormat.mFramesPerPacket = 1;
int bytes = (bitsPerChannel / 8) * channelsPerFrame;
streamFormat.mBytesPerFrame = bytes;
streamFormat.mBytesPerPacket = bytes;
I'm completely a beginner when it comes to audio programming and right now I'm playing around with AudioUnit. I'm following http://www.cocoawithlove.com/2010/10/ios-tone-generator-introduction-to.html and I've ported over the code to work with iOS7. The problem is that I only want it to play the generated sine wave once and not keep on playing the sound wave. I am not sure how to accomplish this though.
Generating audio samples:
OSStatus RenderTone(
void *inRefCon,
AudioUnitRenderActionFlags *ioActionFlags,
const AudioTimeStamp *inTimeStamp,
UInt32 inBusNumber,
UInt32 inNumberFrames,
AudioBufferList *ioData)
{
// Fixed amplitude is good enough for our purposes
const double amplitude = 0.25;
// Get the tone parameters out of the view controller
ToneGeneratorViewController *viewController =
(ToneGeneratorViewController *)inRefCon;
double theta = viewController->theta;
double theta_increment =
2.0 * M_PI * viewController->frequency / viewController->sampleRate;
// This is a mono tone generator so we only need the first buffer
const int channel = 0;
Float32 *buffer = (Float32 *)ioData->mBuffers[channel].mData;
// Generate the samples
for (UInt32 frame = 0; frame < inNumberFrames; frame++)
{
buffer[frame] = sin(theta) * amplitude;
theta += theta_increment;
if (theta > 2.0 * M_PI)
{
theta -= 2.0 * M_PI;
}
}
// Store the updated theta back in the view controller
viewController->theta = theta;
return noErr;
}
Creating AudioUnit:
// Configure the search parameters to find the default playback output unit
// (called the kAudioUnitSubType_RemoteIO on iOS but
// kAudioUnitSubType_DefaultOutput on Mac OS X)
AudioComponentDescription defaultOutputDescription;
defaultOutputDescription.componentType = kAudioUnitType_Output;
defaultOutputDescription.componentSubType = kAudioUnitSubType_RemoteIO;
defaultOutputDescription.componentManufacturer = kAudioUnitManufacturer_Apple;
defaultOutputDescription.componentFlags = 0;
defaultOutputDescription.componentFlagsMask = 0;
// Get the default playback output unit
AudioComponent defaultOutput = AudioComponentFindNext(NULL, &defaultOutputDescription);
NSAssert(defaultOutput, #"Can't find default output");
// Create a new unit based on this that we'll use for output
OSErr err = AudioComponentInstanceNew(defaultOutput, &toneUnit);
NSAssert1(toneUnit, #"Error creating unit: %ld", err);
// Set our tone rendering function on the unit
AURenderCallbackStruct input;
input.inputProc = RenderTone;
input.inputProcRefCon = self;
err = AudioUnitSetProperty(toneUnit,
kAudioUnitProperty_SetRenderCallback,
kAudioUnitScope_Input,
0,
&input,
sizeof(input));
NSAssert1(err == noErr, #"Error setting callback: %ld", err);
// Set the format to 32 bit, single channel, floating point, linear PCM
const int four_bytes_per_float = 4;
const int eight_bits_per_byte = 8;
AudioStreamBasicDescription streamFormat;
streamFormat.mSampleRate = sampleRate;
streamFormat.mFormatID = kAudioFormatLinearPCM;
streamFormat.mFormatFlags =
kAudioFormatFlagsNativeFloatPacked | kAudioFormatFlagIsNonInterleaved;
streamFormat.mBytesPerPacket = four_bytes_per_float;
streamFormat.mFramesPerPacket = 1;
streamFormat.mBytesPerFrame = four_bytes_per_float;
streamFormat.mChannelsPerFrame = 1;
streamFormat.mBitsPerChannel = four_bytes_per_float * eight_bits_per_byte;
err = AudioUnitSetProperty (toneUnit,
kAudioUnitProperty_StreamFormat,
kAudioUnitScope_Input,
0,
&streamFormat,
sizeof(AudioStreamBasicDescription));
NSAssert1(err == noErr, #"Error setting stream format: %ld", err);
Thanks!
The problem is that I only want it to play the generated sine wave once
What you should do is stopping the audio unit after a certain time.
You could, e.g., set an NSTimer when you call AudioOutputUnitStart and then when the timer fires, you call AudioOutputUnitStop (actually, your audio unit disposal code). Even simpler, you could use performSelector:withObject:afterDelay: and call your audio unit disposal method.
Hope this helps.
The title pretty much sums up what I'm trying to achieve. I am trying to use Michael Tyson's TPCircularBuffer inside of a render callback while the circular buffer is getting filled with incoming audio data. I want to send the audio from the render callback to the output element of the RemoteIO audio unit so I can hear it through the device speakers.
The audio is interleaved stereo 16 bit coming in as packets of 2048 frames. Here's how I've set up my audio session:
#define kInputBus 1
#define kOutputBus 0
NSError *err = nil;
NSTimeInterval ioBufferDuration = 46;
AVAudioSession *session = [AVAudioSession sharedInstance];
[session setCategory:AVAudioSessionCategoryPlayback withOptions:AVAudioSessionCategoryOptionMixWithOthers error:&err];
[session setPreferredIOBufferDuration:ioBufferDuration error:&err];
[session setActive:YES error:&err];
AudioComponentDescription defaultOutputDescription;
defaultOutputDescription.componentType = kAudioUnitType_Output;
defaultOutputDescription.componentSubType = kAudioUnitSubType_RemoteIO;
defaultOutputDescription.componentManufacturer = kAudioUnitManufacturer_Apple;
defaultOutputDescription.componentFlags = 0;
defaultOutputDescription.componentFlagsMask = 0;
AudioComponent defaultOutput = AudioComponentFindNext(NULL, &defaultOutputDescription);
NSAssert(defaultOutput, #"Can't find default output.");
AudioComponentInstanceNew(defaultOutput, &remoteIOUnit);
UInt32 flag = 0;
OSStatus status = AudioUnitSetProperty(remoteIOUnit, kAudioOutputUnitProperty_EnableIO, kAudioUnitScope_Input, kOutputBus, &flag, sizeof(flag));
size_t bytesPerSample = sizeof(AudioUnitSampleType);
AudioStreamBasicDescription streamFormat = {0};
streamFormat.mSampleRate = 44100.00;
streamFormat.mFormatID = kAudioFormatLinearPCM;
streamFormat.mFormatFlags = kAudioFormatFlagsCanonical;
streamFormat.mBytesPerPacket = bytesPerSample;
streamFormat.mFramesPerPacket = 1;
streamFormat.mBytesPerFrame = bytesPerSample;
streamFormat.mChannelsPerFrame = 2;
streamFormat.mBitsPerChannel = bytesPerSample * 8;
streamFormat.mReserved = 0;
status = AudioUnitSetProperty(remoteIOUnit, kAudioUnitProperty_StreamFormat, kAudioUnitScope_Output, kInputBus, &streamFormat, sizeof(streamFormat));
AURenderCallbackStruct callbackStruct;
callbackStruct.inputProc = render;
callbackStruct.inputProcRefCon = self;
status = AudioUnitSetProperty(remoteIOUnit, kAudioUnitProperty_SetRenderCallback, kAudioUnitScope_Global, kOutputBus, &callbackStruct, sizeof(callbackStruct));
And here's where the audio data gets loaded into the circular buffer and used in the render callback:
#define kBufferLength 2048
-(void)loadBytes:(Byte *)byteArrPtr{
TPCircularBufferProduceBytes(&buffer, byteArrPtr, kBufferLength);
}
OSStatus render(
void *inRefCon,
AudioUnitRenderActionFlags *ioActionFlags,
const AudioTimeStamp *inTimeStamp,
UInt32 inBusNumber,
UInt32 inNumberFrames,
AudioBufferList *ioData)
{
AUDIOIO *audio = (__bridge AUDIOIO *)inRefCon;
AudioSampleType *outSample = (AudioSampleType *)ioData->mBuffers[0].mData;
//Zero outSample
memset(outSample, 0, kBufferLength);
int bytesToCopy = ioData->mBuffers[0].mDataByteSize;
SInt16 *targetBuffer = (SInt16 *)ioData->mBuffers[0].mData;
//Pull audio
int32_t availableBytes;
SInt16 *buffer = TPCircularBufferTail(&audio->buffer, &availableBytes);
memcpy(targetBuffer, buffer, MIN(bytesToCopy, availableBytes));
TPCircularBufferConsume(&audio->buffer, MIN(bytesToCopy, availableBytes));
return noErr;
}
There is something wrong with this setup because I am not getting any audio through the speakers, but I'm also not getting any errors when I test on my device. As far as I can tell the TPCircularBuffer is being filled and read from correctly. I've followed the Apple documentation for setting up the audio session. I am considering trying to set up an AUGraph next but I want to see if anyone could suggest a solution for what I'm trying to do here. Thanks!
For stereo (2 channels per frame), your bytes per frame and bytes per packet have to be twice your sample size in bytes. Same with bits per channel in terms of bits.
Added: If availableBytes/yourFrameSize isn't almost always as large or larger than inNumberFrames, you won't get much continuous sound.
At a glance, it looks like you've got everything set up correctly. You're missing a call to AudioOutputUnitStart() though:
...
// returns an OSStatus indicating success / fail
AudioOutputUnitStart(remoteIOUnit);
// now your callback should be being called
...
I believe one your problem is with using streamFormat.mBitsPerChannel = bytesPerSample * 8;
You assign bytesPerSample to be sizeof(AudioUnitSampleType) which is essentially 4 bytes.
So streamFormat.mBytesPerPacket = bytesPerSample; is ok.
But the assignment streamFormat.mBitsPerChannel = bytesPerSample * 8; is saying that you want 32 bits per sample instead of 16 bits per sample.
I would not create your audio format based on AudioUnitSampleType because this has nothing to do with your personal format that you want to utilize. I would create defines and do something like this:
#define BITS_PER_CHANNEL 16
#define SAMPLE_RATE 44100.0
#define CHANNELS_PER_FRAME 2
#define BYTES_PER_FRAME CHANNELS_PER_FRAME * (BITS_PER_CHANNEL / 8) //ie 4
#define FRAMES_PER_PACKET 1
#define BYTES_PER_PACKET FRAMES_PER_PACKET * BYTES_PER_FRAME
streamFormat.mSampleRate = SAMPLE_RATE; // 44100.0
streamFormat.mBitsPerChannel = BITS_PER_CHANNEL; //16
streamFormat.mChannelsPerFrame = CHANNELS_PER_FRAME; // 2
streamFormat.mFramesPerPacket = FRAMES_PER_PACKET; //1
streamFormat.mBytesPerFrame = BYTES_PER_FRAME; // 4 total, 2 for left ch, 2 for right ch
streamFormat.mBytesPerPacket = BYTES_PER_PACKET;
streamFormat.mReserved = 0;
streamFormat.mFormatID = kAudioFormatLinearPCM; // double check this also
streamFormat.mFormatFlags = kAudioFormatFlagsCanonical;`
You also need to look at the return values set to err and status immediately after each are run. You still need to add error checking at some of the calls as well such as
checkMyReturnValueToo = AudioComponentInstanceNew(defaultOutput, &remoteIOUnit);
You also have an extremely high value for your buffer duration. You have 46 and I am not sure where that came from. That means you want 46 seconds worth of audio during each audio callback. Usually you want something less than one second depending on your latency requirements. Most likely iOS will not use anything that high but you should try setting it to say 0.025 or so (25ms). You can try to lower it if you need faster latency.
I am new to core audio and remote io. I need data of size 320 bytes which I encode and send. Also a minimum of 50 frames per second. Here is what I have done:
AudioComponentDescription desc;
desc.componentType = kAudioUnitType_Output;
desc.componentSubType = kAudioUnitSubType_RemoteIO;
desc.componentFlags = 0;
desc.componentFlagsMask = 0;
desc.componentManufacturer = 0;
// Get component
AudioComponent inputComponent = AudioComponentFindNext(NULL, &desc);
// Get audio units
AudioComponentInstanceNew(inputComponent, &audioUnit);
// Enable IO for recording
UInt32 flag = 1; AudioUnitSetProperty(audioUnit, kAudioOutputUnitProperty_EnableIO, kAudioUnitScope_Input, kInputBus, &flag, sizeof(flag));
// Enable IO for playback AudioUnitSetProperty(audioUnit, kAudioOutputUnitProperty_EnableIO, kAudioUnitScope_Output, kOutputBus, &flag, sizeof(flag));
UInt32 shouldAllocateBuffer = 1;
AudioUnitSetProperty(audioUnit, kAudioUnitProperty_ShouldAllocateBuffer, kAudioUnitScope_Global, 1, &shouldAllocateBuffer, sizeof(shouldAllocateBuffer));
// Describe format
audioFormat.mSampleRate = 8000.00;
audioFormat.mFormatID = kAudioFormatLinearPCM;
audioFormat.mFormatFlags = kAudioFormatFlagIsSignedInteger|kAudioFormatFlagIsPacked;
audioFormat.mFramesPerPacket = 1;
audioFormat.mChannelsPerFrame = 1;
audioFormat.mBitsPerChannel = 16;
audioFormat.mBytesPerPacket = 2;
audioFormat.mBytesPerFrame = 2;
// Apply format AudioUnitSetProperty(audioUnit, kAudioUnitProperty_StreamFormat, kAudioUnitScope_Output, 1, &audioFormat, sizeof(audioFormat));
AudioUnitSetProperty(audioUnit, kAudioUnitProperty_StreamFormat, kAudioUnitScope_Input, 0, &audioFormat, sizeof(audioFormat));
// Set input callback
AURenderCallbackStruct callbackStruct;
callbackStruct.inputProc = recordingCallback;
callbackStruct.inputProcRefCon = self;
AudioUnitSetProperty(audioUnit, kAudioOutputUnitProperty_SetInputCallback, kAudioUnitScope_Global, 1, &callbackStruct, sizeof(callbackStruct));
// Set output callback
callbackStruct.inputProc = playbackCallback;
callbackStruct.inputProcRefCon = self;
AudioUnitSetProperty(audioUnit, kAudioUnitProperty_SetRenderCallback, kAudioUnitScope_Global, 0, &callbackStruct, sizeof(callbackStruct));
// Initialise
AudioUnitInitialize(audioUnit);
AudioOutputUnitStart(audioUnit);
With this settings, i get 186 frames in the callback method when tried with device.
I have allocated by buffer:
bufferList = (AudioBufferList*) malloc(sizeof(AudioBufferList));
bufferList->mNumberBuffers = 1; //mono input
for(UInt32 i=0;i<bufferList->mNumberBuffers;i++)
{
bufferList->mBuffers[i].mNumberChannels = 1;
bufferList->mBuffers[i].mDataByteSize = 2*186;
bufferList->mBuffers[i].mData = malloc(bufferList->mBuffers[i].mDataByteSize);
}
From this 372(2 x 186) bytes in the callback, i took 320 byte data and used as per my requirement. It is working, but very noisy.
Someone please help me. I am in big trouble.
A couple of suggestions -
Sample rate and buffer size get set using the AVAudioSession class.
386 is an unusual number of frames. Your callback is probably asking for 512 or 1024. You might try using a ring buffer to allow varying varying buffer size/ frame rates to suit your needs.
Here are some examples:
MixerHost
TimeCode
I have a really short audio file, say a 10th of a second in (say) .PCM format
I want to use RemoteIO to loop through the file repeatedly to produce a continuous musical tone. So how do I read this into an array of floats?
EDIT: while I could probably dig out the file format, extract the file into an NSData and process it manually, I'm guessing there is a more sensible generic approach... ( that eg copes with different formats )
You can use ExtAudioFile to read data from any supported data format in numerous client formats. Here is an example to read a file as 16-bit integers:
CFURLRef url = /* ... */;
ExtAudioFileRef eaf;
OSStatus err = ExtAudioFileOpenURL((CFURLRef)url, &eaf);
if(noErr != err)
/* handle error */
AudioStreamBasicDescription format;
format.mSampleRate = 44100;
format.mFormatID = kAudioFormatLinearPCM;
format.mFormatFlags = kAudioFormatFormatFlagIsPacked;
format.mBitsPerChannel = 16;
format.mChannelsPerFrame = 2;
format.mBytesPerFrame = format.mChannelsPerFrame * 2;
format.mFramesPerPacket = 1;
format.mBytesPerPacket = format.mFramesPerPacket * format.mBytesPerFrame;
err = ExtAudioFileSetProperty(eaf, kExtAudioFileProperty_ClientDataFormat, sizeof(format), &format);
/* Read the file contents using ExtAudioFileRead */
If you wanted Float32 data, you would set up format like this:
format.mFormatID = kAudioFormatLinearPCM;
format.mFormatFlags = kAudioFormatFlagsNativeFloatPacked;
format.mBitsPerChannel = 32;
This is the code I have used to convert my audio data (audio file ) into floating point representation and saved into an array.
-(void) PrintFloatDataFromAudioFile {
NSString * name = #"Filename"; //YOUR FILE NAME
NSString * source = [[NSBundle mainBundle] pathForResource:name ofType:#"m4a"]; // SPECIFY YOUR FILE FORMAT
const char *cString = [source cStringUsingEncoding:NSASCIIStringEncoding];
CFStringRef str = CFStringCreateWithCString(
NULL,
cString,
kCFStringEncodingMacRoman
);
CFURLRef inputFileURL = CFURLCreateWithFileSystemPath(
kCFAllocatorDefault,
str,
kCFURLPOSIXPathStyle,
false
);
ExtAudioFileRef fileRef;
ExtAudioFileOpenURL(inputFileURL, &fileRef);
AudioStreamBasicDescription audioFormat;
audioFormat.mSampleRate = 44100; // GIVE YOUR SAMPLING RATE
audioFormat.mFormatID = kAudioFormatLinearPCM;
audioFormat.mFormatFlags = kLinearPCMFormatFlagIsFloat;
audioFormat.mBitsPerChannel = sizeof(Float32) * 8;
audioFormat.mChannelsPerFrame = 1; // Mono
audioFormat.mBytesPerFrame = audioFormat.mChannelsPerFrame * sizeof(Float32); // == sizeof(Float32)
audioFormat.mFramesPerPacket = 1;
audioFormat.mBytesPerPacket = audioFormat.mFramesPerPacket * audioFormat.mBytesPerFrame; // = sizeof(Float32)
// 3) Apply audio format to the Extended Audio File
ExtAudioFileSetProperty(
fileRef,
kExtAudioFileProperty_ClientDataFormat,
sizeof (AudioStreamBasicDescription), //= audioFormat
&audioFormat);
int numSamples = 1024; //How many samples to read in at a time
UInt32 sizePerPacket = audioFormat.mBytesPerPacket; // = sizeof(Float32) = 32bytes
UInt32 packetsPerBuffer = numSamples;
UInt32 outputBufferSize = packetsPerBuffer * sizePerPacket;
// So the lvalue of outputBuffer is the memory location where we have reserved space
UInt8 *outputBuffer = (UInt8 *)malloc(sizeof(UInt8 *) * outputBufferSize);
AudioBufferList convertedData ;//= malloc(sizeof(convertedData));
convertedData.mNumberBuffers = 1; // Set this to 1 for mono
convertedData.mBuffers[0].mNumberChannels = audioFormat.mChannelsPerFrame; //also = 1
convertedData.mBuffers[0].mDataByteSize = outputBufferSize;
convertedData.mBuffers[0].mData = outputBuffer; //
UInt32 frameCount = numSamples;
float *samplesAsCArray;
int j =0;
double floatDataArray[882000] ; // SPECIFY YOUR DATA LIMIT MINE WAS 882000 , SHOULD BE EQUAL TO OR MORE THAN DATA LIMIT
while (frameCount > 0) {
ExtAudioFileRead(
fileRef,
&frameCount,
&convertedData
);
if (frameCount > 0) {
AudioBuffer audioBuffer = convertedData.mBuffers[0];
samplesAsCArray = (float *)audioBuffer.mData; // CAST YOUR mData INTO FLOAT
for (int i =0; i<1024 /*numSamples */; i++) { //YOU CAN PUT numSamples INTEAD OF 1024
floatDataArray[j] = (double)samplesAsCArray[i] ; //PUT YOUR DATA INTO FLOAT ARRAY
printf("\n%f",floatDataArray[j]); //PRINT YOUR ARRAY'S DATA IN FLOAT FORM RANGING -1 TO +1
j++;
}
}
}}
I'm not familiar with RemoteIO, but I am familiar with WAV's and thought I'd post some format information on them. If you need, you should be able to easily parse out information such as duration, bit rate, etc...
First, here is an excellent website detailing the WAVE PCM soundfile format. This site also does an excellent job illustrating what the different byte addresses inside the "fmt" sub-chunk refer to.
WAVE File format
A WAVE is composed of a "RIFF" chunk and subsequent sub-chunks
Every chunk is at least 8 bytes
First 4 bytes is the Chunk ID
Next 4 bytes is the Chunk Size (The Chunk Size gives the size of the remainder of the chunk excluding the 8 bytes used for the Chunk ID and Chunk Size)
Every WAVE has the following chunks / sub chunks
"RIFF" (first and only chunk. All the rest are technically sub-chunks.)
"fmt " (usually the first sub-chunk after "RIFF" but can be anywhere between "RIFF" and "data". This chunk has information about the WAV such as number of channels, sample rate, and byte rate)
"data" (must be the last sub-chunk and contains all the sound data)
Common WAVE Audio Formats:
PCM
IEEE_Float
PCM_EXTENSIBLE (with a sub format of PCM or IEEE_FLOAT)
WAVE Duration and Size
A WAVE File's duration can be calculated as follows:
seconds = DataChunkSize / ByteRate
Where
ByteRate = SampleRate * NumChannels * BitsPerSample/8
and DataChunkSize does not include the 8 bytes reserved for the ID and Size of the "data" sub-chunk.
Knowing this, the DataChunkSize can be calculated if you know the duration of the WAV and the ByteRate.
DataChunkSize = seconds * ByteRate
This can be useful for calculating the size of the wav data when converting from formats like mp3 or wma. Note that a typical wav header is 44 bytes followed by DataChunkSize (this is always the case if the wav was converted using the Normalizer tool - at least as of this writing).
Update for Swift 5
This is a simple function that helps get your audio file into an array of floats. This is for both mono and stereo audio, To get the second channel of stereo audio, just uncomment sample 2
import AVFoundation
//..
do {
guard let url = Bundle.main.url(forResource: "audio_example", withExtension: "wav") else { return }
let file = try AVAudioFile(forReading: url)
if let format = AVAudioFormat(commonFormat: .pcmFormatFloat32, sampleRate: file.fileFormat.sampleRate, channels: file.fileFormat.channelCount, interleaved: false), let buf = AVAudioPCMBuffer(pcmFormat: format, frameCapacity: AVAudioFrameCount(file.length)) {
try file.read(into: buf)
guard let floatChannelData = buf.floatChannelData else { return }
let frameLength = Int(buf.frameLength)
let samples = Array(UnsafeBufferPointer(start:floatChannelData[0], count:frameLength))
// let samples2 = Array(UnsafeBufferPointer(start:floatChannelData[1], count:frameLength))
print("samples")
print(samples.count)
print(samples.prefix(10))
// print(samples2.prefix(10))
}
} catch {
print("Audio Error: \(error)")
}