River Past Audio Converter is an easy-to-use, fast, and powerful batch audio conversion and extractor software.

It outputs AIF, AVI, MKA (Matroska Audio), MP3, OGG Vorbis, WAV or WMA.

With River Past MPEG-4 Booster Pack installed, you can output to M4A (MPEG-4 AAC audio), the format used by iTune and iPod.
With MPEG-2 Booster Pack, you can convert to MPEG Audio layer-2.

It can convert from Dolby Digital AC-3, Apple AIF (AIFF/AIFC), Monkey audio APE, Unix AU, FLAC (Free Lossless Audio Codec), MP3 (MPEG Layer-3), M4A (MPEG-4 Audio), MKA (Matroska Audio), MPA (MPEG-1 Audio), MPC (MusePack/MPEG Plus), OFR (OptimFROG), OGG Vorbis, RealAudio RA/RAM, SD2 (Sound Designer 2), SND, TTA (The True Audio encoder), WAV and WMA (Windows Media Audio). It can also extract audio from mobile phone 3G video (3GPP/3GPP2), ASF (Advanced Streaming Format), AVI, VCD DAT, DivX, DV, IVF, MKV (Matroska Video), QuickTime MOV, MP4 (MPEG-4 video), MPG (MPEG-1 and MPEG-2 Video), RealMedia RM, OGM (OGG Media), DVD VOB, WMV (Windows Media Video) and XviD.

It can rip audio from DVD-Video chapters.

You have the full control over the codec, sample rate, channel, bits per sample, and bitrate settings. For WMA output, you can also choose from a list of Windows Media profiles.

Audio Converter Pro adds the ability to preview, trim clip, and to convert audio without re-encoding if possible.

Tags are supported for MOV, WMA and MP3 formats. There is a built-in tag editor.

Now, you have the ability to add a DirectShow decoding method (file reader, splitter, decoder) to expand the input file format support.