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MPEG Audio Utility

Release: 0.24

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Description

This Utility analyzes all frames of MPEG-1, MPEG-2 or MPEG-2.5 audio files compressed with Layer I, II or III.
In case of Layer III files additionaly the gain (volume) may be modified. This is lossless. It is implemented by modifying all side info blocks of the file. This restricts the step size to 1.5 dB.
Furthermore Layer III files may be stripped. This means that leading and trailing silence (empty frames) is removed. (new)

Usage

installation

Copy the executable files somewhere to your harddrive. Copy the file gcc30s.dll somewhere to your libpath.[1]
Create a program object for it and modify the settings to not to close the window on exit. If you like to modify the gain of the files by this way, you should enter [options] "%*" as parameter of the program. You will be asked for additional options in every case.
If you prefer command windows, place the executable somewhere in your PATH.

usage

Simply drop an MPEG file on the program object or enter frameanalyzer filename.

command line options

/v
Print a verbose info of every (valid) frame.
/lnum
Modify gain by 1.5 · numdB. Negative values will decrease the volume.
Remember that you can overdrive the file. However not the MPEG stream is overdriven but the decoder engine will overdrive when the samples are quantized to 16 bit. So, fortunately this is reversable unless you left the domain of the gain fields, which is nearly impossible as they have a dynamic range of 380dB.
/sthres
Strip leading and trailing empty frames.
This will remove only silence. Due to the bit reservoir of MPEG Layer III files, usually a few frames with silence will remain at the beginning. thres is number of different bytes per empty frame. It defaults to 10 if omitted. If thres is negative then the gain fields of the sideinfo blocks are ignored. In this case only the entropy of the frame is taken to identify silence. You need this for FhG encoded files, where the gain fields contain nonsens for empty frames.
This option also removes the futile wave header of some files, which confuses some applications.

Notes:

  1. The file gcc30s.dll is the C++ runtime of gcc 3.0. Other applications may use this too. However, if you have gcc 3.0 istalled you will already have the DLL.


Download

This program is distributed under the terms of the
GNU GENERAL PUBLIC LICENSE.

ZIP file with source, OS/2 binary and this guide: Version 0.24


History

Version 0.24

Version 0.23 Version 0.22 Version 0.21 Version 0.2


ToDo

Create correct CRC fields
Currently the (optional) CRC fileds of the MP3 frames are not updated.
Gain changes of Layer I and II files
Up to now I don't know the format of the sideinfo blocks of Layer I and II files, if there are any.

Contact

Suggestions, help, complaints (but not too much:-): mueller@maazl.de

Original homepage: http://www.maazl.de/project/mp3/mp3frame.html