CH_WAVE(1)

💖 CH_WAVE(1) 💖

okay bestie, welcome to the General Commands Manual entry for ch_wave — she's a little Scottish (Edinburgh Speech Tools, iykyk) and she does SO much. buckle up 🎀

✨ NAME ✨

ch_wave — change/copy/combine waveform files

like. that's the whole job description and honestly? she ate.

🌸 SYNOPSIS 🌸

ch_wave [-h] [-itype file type] [-n channels] [-f sample rate]
        [-ibo byte order] [-iswap] [-istype sample type] [-c channel]
        [-start seconds] [-end seconds] [-from sample] [-to sample]
        [-o output file] [-otype file type] [-F sample rate]
        [-obo byte order] [-oswap] [-ostype sample type] [-scale factor]
        [-scaleN factor] [-lpfilter frequency] [-hpfilter frequency]
        [-forder order] [-fafter] [-info] [-add] [-pc LONGEST | FIRST]
        [-key keylab file] [-divide] [-ext file extension]
        [-extract file] input files ...

periodt. that's the whole summoning ritual 💅

🦋 DESCRIPTION 🦋

so ch_wave does various operations on an input waveform file and writes it out to another file. and when she says various, she MEANS it — she can extract subsections, pull out individual channels, resample, rescale, mix down channels, and do simple filtering operations. main character energy fr fr. 👑

The following option flags are recognized:

• -h — options help. she tells you what she can do 🫶
• -itype file type — input file type (optional). If you set it to raw, that means your input file has no header at all. you can use this to specify file types other than raw, but honestly nobody really does that, because the file type of all the existing supported types can be figured out automatically from the file's header. and if the input file is unheadered, files are assumed to be shorts (16bit). Supported types are nist, est, esps, snd, riff, aiff, audlab, raw, ascii ✨
• -n channels — number of channels in an unheadered input file
• -f sample rate — sample rate in Hertz for an unheadered input file
• -ibo byte order — input byte order in an unheadered input file. the possibilities are: MSB, LSB, native or nonnative. Suns, HP, SGI Mips, M68000 are MSB (big endian). Intel, Alpha, DEC Mips, Vax are LSB (little endian)
• -iswap — swap bytes. (for use on an unheadered input file) 🔄
• -istype sample type — sample type in an unheadered input file: short, alaw, mulaw, byte, ascii
• -c channel — select a single channel (starts from 0). waveforms can have multiple channels. this option extracts a single channel for progcessing and discards the rest. (yes, "progcessing" — that's the original typo and I'm keeping it, she's iconic like that 💀)
• -start seconds — extract sub-wave starting at this time, specified in seconds
• -end seconds — extract sub-wave ending at this time, specified in seconds
• -from sample — extract sub-wave starting at this sample point
• -to sample — extract sub-wave ending at this sample point
• -o output file — output filename. if not specified, output is to stdout
• -otype file type — output file type (optional). if no type is Specified, the type of the input file is assumed. Supported types are: nist, est, esps, snd, riff, aiff, audlab, raw, ascii
• -F sample rate — output sample rate in Hz. if this is different from the input sample rate, resampling will occur
• -obo byte order — output byte order: MSB, LSB, native, or nonnative. Suns, HP, SGI Mips, M68000 are MSB (big endian), Intel, Alpha, DEC Mips, Vax are LSB (little endian)
• -oswap — swap bytes when saving to output 🔄
• -ostype sample type — output sample type: short, alaw, mulaw, byte or ascii
• -scale factor — scaling factor. increase or descrease the amplitude of the whole waveform by the factor given (relative to 1.0)
• -scaleN factor — scaling factor with normalization. the waveform is scaled to its maximum level, after which it is scaled by the factor given (relative to 1.0)
• -lpfilter frequency — low pass filter, with cutoff frequency in Hz. filtering is performed by a FIR filter which is built at run time. the order of the filter can be given by -forder. the default value is 199 🌊
• -hpfilter frequency — high pass filter, with cutoff frequency in Hz. filtering is performed by a FIR filter which is built at run time. the order of the filter can be given by -forder. the default value is 199.
• -forder order — order of FIR filter used for lpfilter and hpfilter. this must be ODD. sensible values range from 19 (quick but with a shallow rolloff) to 199 (slow but with a steep rolloff). the default is 199.
• -fafter — do filtering after other operations such as resampling (default : filter before other operations)
• -info — print information about file and header. this option gives useful info like file length, sampling rate, number of channels etc. no output is produced 📋
• -add — a new single channel waveform is created by adding the corresponding sample points of each input waveform ➕
• -pc LONGEST | FIRST — combine input waveforms to form a single multichannel waveform. the argument to this option controls how long the new waveform should be. if the option is LONGEST, the output wave if the length of the longest input wave and shorter waves are padded with zeros at the end. if the option is FIRST, the length of the new waveform is the length of the first file on the command line, and subsequent waves are padded or cut to this length
• -key keylab file — label file designating subsections, for use with -divide. the KEYLAB file is a label file which specifies where chunks (such as individual sentences) in a waveform begin and end. see section on wave extraction. 🔑
• -divide — divide a single input waveform into multiple output waveforms. each output waveform is extracted from the input waveform by using the KEYLAB file, which specifies the start and stop times for each chunk. the output files are named according to the filename in the KEYLAB file, with extension given by -ext. see section on wave extraction
• -ext file extension — file extension for divided waveforms
• -extract file — used in conjunction with -key to extract a single section of waveform from the input waveform. the argument is the name of a file given in the file column of the KEYLAB file.

🧚 EXAMPLES 🧚

bestie... this section is empty in the original. no examples. we simply have to imagine. 😭 she left us on read.

💀 BUGS 💀

also empty. not a single bug documented. either she's perfect or nobody filed a report. (it's giving "works on my machine" energy, ngl.)

🌈 SEE ALSO 🌈

ch_track(1) ch_utt(1) na_record(1) na_play(1)

go read those too, they're all in the family 💜

okay that's the whole page!! and finally, the little sign-off at the bottom of the original, folded into a cute little bow for you: this page comes from the Edinburgh Speech Tools, dated April 5, 2001, and it's filed under CH_WAVE(1). yes she's vintage, no that does not make her any less of a queen 👑✨ bye bestie, go make some waveforms 🎀