MP3packer (written by Omion over at HydrogenAudio) 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. So, the original idea of MP3packer was created to reduce the size of high bitrate CBR files, turning them into VBR files. However, MP3packer can also turn VBR files into CBR.
The WinMP3Packer download below contains MP3packer
- Usually makes 320kbps files 2-10% smaller LOSSLESSLY
- Corrects errors of the MP3 bitstream (sync errors / buffer errors)
- 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/Xing header for proper VBR seeking and gapless playback
- Provides the ability to losslessly turn VBR files into larger CBR files to humor players which can't handle VBR
- Strip headers from the start and/or end of the files
- GPL, so anybody can tweak it as long as it stays GPL
- Works on MP2 files also
- Includes a brute-force compression optimization option to further compress files
- Supports Unicode file names and paths
- Supports encoding an entire directory of files
- Multi-core support
- 64-bit support (precompiled Windows executable builds for 32 and 64 bit available)
A few caveats
- It's only been tested it on Win32. It should work just fine on any UNIXish OS with an OCaml port.
- 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.
- Reduction in size, as mentioned in the MP3packer features can be very small: do not expect miracles
- There is a limitation in that it cannot repack Freeformat MP3s
MP3packer Optimization Solutions
WinMP3Packer is a frontend for the MP3packer program written by Chris Close (psyllium) also over at HydrogenAudio. You'll need the .NET Framework (2.0) installed to use this GUI.
Download the latest version from:
- WinMP3Packer-1.0.18-alpha-2.04.7z (packaged with mp3packer v2.04)
- WinMP3Packer-1.0.18-alpha.zip (packaged with mp3packer v1.20)
- see MP3packer features
- Allows for batch processing: multiple files and folders may be selected
- Allows for processing whole folders. Will also recurse into the sub-folders and process the files in there
- When processing whole folders, the option 'Recreate sub-folders' will put the output files into the same sort of directory structure as the input files
- Easy update to the latest version of MP3packer by simply overwriting the mp3packer.exe in the WinMP3Packer folder with the latest mp3packer.exe version