AAC to AIF: Convert Audio from AAC(Advanced Audio Coding) to AIF(AIFF/AIFC Apple Audio) with River Past Audio Converter, AAC2AIF converter, conversion

What is AAC?

AAC, Advanced Audio Coding, is a technique for compressing digital audio files. Officially part of the MPEG-4 standard, it is most widely used to create small digital audio files.

AAC is conceptually similar to the ubiquitous MP3 format. AAC is a lossy algorithm, meaning the original digital audio cannot be recreated from the compressed bits alone. In terms of audio fidelity, however, there is no loss of data if the compressed audio is properly encoded. AAC claims an advantage over MP3 in this regard: while MP3 requires a bit rate of approximately 256 kilobits per second (kbps) to achieve transparency, AAC can achieve the same quality at 128 kbps. This allows AAC files to be roughly half the size of MP3 files of the same quality, and one-tenth the size of CD digital data.

AAC provides several other advantages over MP3. It is capable of handling much higher and lower frequencies of sound, provides up to 48 channels of audio, and allows the creation of low-latency audio necessary for two-way communication.

There are two types of AAC files. The most common one is embedded in MPEG-4 container. Its file extension is usually m4a. The popular iTunes encode AAC audio in this format. You only need to have Apple QuickTime installed to decode these files.

A less common one is the plain AAC file, usually with .aac file extension. To convert from this type, you need to have DC-Bass Decoder installed.

What is AIF?

Short for Audio Interchange File Format, a common format for storing and transmitting sampled sound. The format was developed by Apple Computer and is the standard audio format for Macintosh computers. It is also used by Silicon Graphics Incorporated (SGI).

The AIFF format is uncompressed so AIFF files tend to be large. However, there is another format called AIFF-Compressed (AIFF-C or AIFC) that supports compression ratios as high as 6:1.

AIFF files generally end with an .AIF or .IEF extension.

AIFC files generally end with an .AIFC extension.

AIFF and AIFC are standard audio format used on MacOS systems. AIFF is not compressed. AIFC is compressed.

To encode AIF audio, please make sure Apple QuickTime is installed.

Launch River Past Audio Converter

Once River Past Audio Converter is installed properly, launch Audio Converter.

Add File

Click on the "Add File" button on the tool bar. The standard file open dialog appears. Select "AAC - Advaned Audio Coding" in its "Files of type" combo box.

Note: To convert from AAC files, you must have DC-Bass Decoder installed.

River Past Audio Converter

Select output format

Use the setting panel on the bottom of the window to control the output format. Click on the toggle to the left of the "Format" label to expand the panel. Select "AIF - Audio Interchanged File Format" as the "Audio Type".

Troubleshoot

If you don't see the AIF output option, you have a problem with your QuickTime installation.

You need to have the latest QuickTime installed. Occasionally, QuickTime may be corrupted. In any case, reinstall QuickTime should fix this problem.

You can change the compressor, and depending on the compressor, you can change the sample rate, channel (stereo or mono), bits/sample, and bitrate.

When "16 bit LPCM" or "16 bit PCM" is selected as the "Compressor", the file is uncompressed, and satisfy the original AIFF specification. When other compressors are used, the file is compressed and is considered to be an AIFC file.