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A very high level question. I'm investigating the possibility of an app that would do 2-3 hr audio recordings at a time.

Does anyone know an proximate minute per MB rate for low (voice quality) level recordings? Now I know this can depend on lots of factors but I'm just looking for an approximate figure to see how feasible this can be for something 2-3 hrs long.

Thanks!

AlexVPerl
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2 Answers2

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At CD quality (44.1k Samples/per second) for a single channel you get 158.76 M samples for a 1 hour stretch. Multiply that by the sample size (say a 16 bit int) and you get 317.52 MB per hour per channel. This is worst case, and I bet you could implement compression to reduce the physical size.

See SO questions like how-to-record-voice-with-an-ipad

Community
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Peter M
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Here are the results for few encoding supported by iPhone. Size of audio file in KB of duration 10 sec. kAudioFormatMPEG4AAC : 164, kAudioFormatAppleLossless : 430, kAudioFormatAppleIMA4 : 475, kAudioFormatULaw : 889, kAudioFormatALaw : 889, Among these kAudioFormatMPEG4AAC is having smallest size

This answer I get from website. Just for your reference.

kongyang
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