M4A file options in Logic Pro for iPad
When you tap the Information button to the right of Compressed in the Export Options dialog in Logic Pro for iPad, the following options appear:
M4A: An audio file type with two encoding options.
Encoding: Choose Advanced Audio Codec (AAC) or Apple Lossless (ALAC) to set the encoding for your M4A file. Although both encoding algorithms provide high-quality audio, the AAC format uses a higher compression ratio, resulting in smaller file sizes.
Bit Rate: Choose a rate from 64 kbit/s to 320 kbit/s.
Encode with variable bit rate (VBR): Variable bit rate encoding compresses simpler passages more heavily than passages that are harmonically rich, generally resulting in higher-quality files.
Note: Choosing ALAC disables the options for bit rate and encode with variable bit rate.
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