MP3packer

MP3packer (written by Omion over at HydrogenAudio.org) attempts to save space by storing frame data in the smallest possible frame. Usually MP3s are already stored in the most efficient way possible. However, for high-bitrate CBR files, e.g. 320kbps (created via LAME '-b 320' aka '--preset insane' for example) there can be a lot of wasted space.

Download

Download the latest version from:

• http://www.hydrogenaudio.org/forums/index.php?showtopic=32379&hl=mp3repacker

Features

• Usually makes 320kbps files 2-10% smaller LOSSLESSLY
• Squeezes out all the padding it can from any MP3 (Will not produce a larger file, unless you use the '-b' switch)
• Writes valid LAME header for proper VBR seeking
• Goes exceedingly fast thanks to the OCaml rewrite
• Uses much less memory than the old '-m' mode
• Many people also use this backwards, to losslessly turn VBR into larger CBR files to humor players that can't handle VBR
• GPL, so anybody can tweak it as long as it stays GPL

A few caveats

• It's only been tested it on Win32. It should work just fine on any UNIXish OS with an OCaml port.
• Full-directory processing has been 'undone' with the rewrite. Should be put back soon
• The program will always output an MP3 that doesn't use CRCs (Cyclical Redundancy Checking), even if the input file uses CRC. This is primarily laziness on the author's part, but nobody really needs them, and it saves 600 bits per second.