What methods in what Framework to separate an audio file into two files?

Question

Created Aug ’24

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I'm having trouble using SFSpeechRecognizer & SFSpeechRecognitionTask to show me the words from an audio file. I found a solution on stackoverflow to separate the audio file into smaller sizes. How would I do that programmatically using Swift for a macOS app Xcode project?

I would prefer not to separate the file into smaller files. I will submit another post with more information for that.

Answered by Engineer in 801371022

You can use AVAudioFile for that. Below is an example. The firstHalfUrl and secondHalfUrl variables are URLs where you'd want to save the first and second halves of the original file.

Instead of saving smaller files, you might want to append(_:) the AVAudioPCMBuffers directly to a SFSpeechAudioBufferRecognitionRequest.

let url = Bundle.main.url(forResource: "file", withExtension: "ext")
let file = try AVAudioFile(forReading: url, commonFormat: .pcmFormatInt16, interleaved: true)

let frames = file.length / 2
let buffer = AVAudioPCMBuffer(pcmFormat: file.processingFormat, frameCapacity: AVAudioFrameCount(frames))

try file.read(into: buffer, frameCount: AVAudioFrameCount(frames))
try AVAudioFile(forWriting: firstHalfUrl, settings: file.fileFormat.settings).write(from: buffer)

file.framePosition = frames
try file.read(into: buffer, frameCount: AVAudioFrameCount(frames))
try AVAudioFile(forWriting: secondHalfUrl, settings: file.fileFormat.settings).write(from: buffer)

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Answer 1

Engineer OP

Apple

Aug ’24

Accepted Answer

You can use AVAudioFile for that. Below is an example. The firstHalfUrl and secondHalfUrl variables are URLs where you'd want to save the first and second halves of the original file.

Instead of saving smaller files, you might want to append(_:) the AVAudioPCMBuffers directly to a SFSpeechAudioBufferRecognitionRequest.

let url = Bundle.main.url(forResource: "file", withExtension: "ext")
let file = try AVAudioFile(forReading: url, commonFormat: .pcmFormatInt16, interleaved: true)

let frames = file.length / 2
let buffer = AVAudioPCMBuffer(pcmFormat: file.processingFormat, frameCapacity: AVAudioFrameCount(frames))

try file.read(into: buffer, frameCount: AVAudioFrameCount(frames))
try AVAudioFile(forWriting: firstHalfUrl, settings: file.fileFormat.settings).write(from: buffer)

file.framePosition = frames
try file.read(into: buffer, frameCount: AVAudioFrameCount(frames))
try AVAudioFile(forWriting: secondHalfUrl, settings: file.fileFormat.settings).write(from: buffer)

1

Answer 2

UtiliAppsLLC OP

Aug ’24

Thank you.

0

Answer 3

UtiliAppsLLC OP

Aug ’24

I'm not using SFSpeechAudioBufferRecognitionRequest. I actually thought that is only used for a livestream or for audio coming directly from a microphone.

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