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Coding query - Is this just a 8khz wav file?

Posted: Sun Jan 04, 2015 9:34 pm
by Pineappley
Hi,

I need to produce a voice recording with these specifications,

'Signed linear’ 8khz, 16-bit signed integer, little-endian raw format'

Is this just a .wav file recorded at a project rate of 8000z?

If not can how do I record/export in this format? I can use either the MAC version or WINDOWS.

Thanks for any help.

Re: Coding query - Is this just a 8khz wav file?

Posted: Mon Jan 05, 2015 1:20 am
by DVDdoug
Before exporting, change the sample rate in the lower-left of the Audacity window (Project Rate).

Then, Export
Save as type: Other Uncompressed Formats
Options: Header: RAW (header-less) Encoding: Signed 16-bit PCM

You'll have to "cross your fingers" for little-endian, because there is no way in Audacity to select the option. When you import a raw file, you can specify little-endian or big-endian, but apparently not when you export.
Is this just a .wav file recorded at a project rate of 8000z?
No. It's similar to a WAV file but a "raw" file does not have the WAV header. In general, you need special software (that already knows the format details) to play a raw file, because there is no header indicating the format. If you open a raw file in Audacity (or other audio editor) you need to tell Audacity the sample rate, bit, depth, etc.

If open or play a WAV file in place of a raw file, the header will be read as audio and you'll get a "glitch" in the sound at the beginning of the file. You could also get an offset problem that screws-up the "endiness", and with the byte-order mixed-up you can get pure-noise.

Re: Coding query - Is this just a 8khz wav file?

Posted: Mon Jan 05, 2015 10:12 am
by Pineappley
Thank you.

Re: Coding query - Is this just a 8khz wav file?

Posted: Mon Jan 19, 2015 5:51 pm
by rj7500
Just a bit confused. I have a client who would like a file as PCM 8Khz 16 bit. Is that simply a WAV file adjusted?

Bob

Re: Coding query - Is this just a 8khz wav file?

Posted: Tue Jan 20, 2015 1:29 am
by steve
rj7500 wrote: I have a client who would like a file as PCM 8Khz 16 bit. Is that simply a WAV file adjusted?
Just set the "Project Rate" (lower left corner of the main Audacity window) to 8000 before you export, and export as a "normal" (16 bit PCM) WAV file.
If they want a mono file, you will need to ensure that the audio in the project is mono before you export.