AV Foundation wastes energy processing Audio even if not captured
||Date Originated:||21 march 2014|
||Product Version:||iOS 7.1 (11D167)|
Apps which have no interest in capturing audio still incur energy waste for processing audio.
In my usage scenario (see sample) I am connecting the back-facing camera with a capture session and a metadata detector output for scanning barcodes. I have no interest in audio. Yet, in the Energy Diagnostics Instrument the "Audio Processing" bars hover around 20%.
From this I infer that Audio Processing is occurring even though it wouldn't have to. There does not appear any way for a developer to indicate to iOS that audio should be ignored.
Steps to Reproduce:
1. Open the provided sample app in Xcode
2. Profile it with the "Energy Diagnostics" Instrument
The Audio Processing (blue) portion of CPU Activity should be near 0%.
Audio Processing is around 20% on an iPhone 5S.
iOS 7.1 (11D167)
Please give information if this is intended behavior. Would it be a good enhancement to request to be able to instruct AV Foundation to ignore audio for barcode scanning scenarios like this?
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