Miscellaneous wave audio utilities

• Remove leading and trailing silence from wave files.
• Split wave files at MP3 (or other) frame boundaries.

Remove leading and trailing silence from wave files

Download stripwave.zip (OS/2 binary and source)

Usage: stripwave filename [threshold [threshold at end]] [options]
If threshold is omitted you will be asked for it after a scan.
/t Truncate additional data, p.e. suspicious messages of used applications.

This utility strips all samples from the beginning and the end of a wave file which have absolute values less than or equal to a given threshold.

If you use the interactive mode the data is analyzed first. As result you will see a table with the number of bytes removed for different thresholds. Additionally the difference in the number of bytes to the next lower threshold is shown. Usually the amplitude of the background noise level is indicated by a high difference. The program tries to find good threshold values automatically. If you just press enter this values will be used. You may enter a different level or abort with Ctrl-Break.

• The program will not work properly, if the file has a DC offset.
• The automatic threshold detection will give unreliable results if the file has been stripped, already.
• A threshold of 0 is always uncritical.
• A threshold of 2 will usually remove quantization noise from CD grabbings.
• Values up to approximately 6 are usually reasonable. But some old (or bad) recordings may require a much higher level.

Split wave files at frame boundaries

Download stripwave.cmd (REXX script)
This utility uses CopyWave by Carsten Arnold which must be somewhere in your PATH.

This tools is designed to split wave files into tracks with the ability to be converted to MPEG audio or CD-XA without gaps. This is useful for live recordings or continuous CDs.
It effectively rounds the track marks to multiples of the frame size. Normally all rounding is relative to the starting point, which is not rounded by default. The last track is also not rounded by default.

Usage

splitwave [options] wavefile start [split [split]] end
Positions may be specified in seconds or minutes:seconds or hours:minutes:seconds. If they are preceded with + it counts relative to the previous one. The Last Position may be * which means up to the end of the source file.
The destination files are named automatically wavefile01, wavefile02, ...

Options

/r or /rmp2 or /rmp3		Round split points to full MP2/MP3 frames (1152 samples).
/rmp1		Round split points to full MP1 frames (384 samples).
/rf or /rframes		Round split points to full CD frames (588 samples).
/rs or /rstart		Round absolute starting position also.
/re or /rend		Round last part also.
/r+		Always round up.
/r-		Always round down.
/f or /frames		Positions are given in CD frames.
/s or /samples		Positions are given in samples.
/nnumber		Start with destination file number instead of 01.
/n		Auto detect Track number from CDT-Track EA.