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From: <pf...@fa...> - 2015-12-14 11:52:39
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Hi, The microphone is a dodotronic ultramic: http://www.dodotronic.com/index.php/ultramics/. I'm working on bat echolocation. The reason I posted my question to this list was because I thought sox might be using some other driver (other than audacity) behind the scenes. On Fri, Dec 11, 2015, at 08:05 PM, Jan Stary wrote: > On Dec 11 17:57:21, pf...@fa... wrote: > > I have a high sample rate (250 khz) USB microphone. > > May I ask what kind of microphone this is exactly, > and what ultrasounds you plan to record with it? > > > I've tried to record from it using matlab, audacity and the command tool > > arecord. However, to no avail. All these tools return the same error: > > the sample rate is wrong. > > I'm afraid this has nothing to do with SoX. > Ask on _their_ mailing lists. > > But I wouldn't be surprised if a recording tool refused > to record at 250 kHz. It is also possible that it's SoX > doing the resampling for you - on my old MacBook > (which surely cannot record at 250000 Hz), I get > > $ rec -r 250000 file.wav > fCoreAudioDriverUID AppleHDAEngineInput:1 > rec WARN formats: can't set sample rate 250000; using 44100 > > Input File : 'default' (coreaudio) > Channels : 2 > Sample Rate : 44100 > Precision : 32-bit > Sample Encoding: 32-bit Signed Integer PCM > > In:0.00% 00:00:01.70 [00:00:00.00] Out:413kk [ | ] Clip:0 ^C > Aborted. > > $ soxi file.wav > > Input File : 'file.wav' > Channels : 2 > Sample Rate : 250000 > Precision : 32-bit > Duration : 00:00:01.65 = 412896 samples ~ 123.869 CDDA sectors > File Size : 3.30M > Bit Rate : 16.0M > Sample Encoding: 32-bit Signed Integer PCM > > > > However, using sox, I can record without problems. Generating a > > spectrogram from sound with a known frequency confirms that the sample > > rate is indeed 250khz - also the files contain (give or take some > > samples) the correct number of samples. > > You don't a spectrogram for that, plain old soxi(1) will tell you. > Also, the sample rate has nothing to do with the "known frequency" > of the sound you are recording. > > > So, my question is, why can i record using sox > > but not any of the other tools. > > Ask _them_. > > > In case it helps, I have attached the sox output below. > > You also need to attach the command line you used. > > > ---------------- > > rec: SoX v14.4.1 > > > > Input File : 'hw:2,0' (alsa) > > Channels : 1 > > Sample Rate : 250000 > > Hm, this looks like the device _is_ actually set to 250000. > In the example above, the devie is actually set to 44100, > and it's SoX resampling for me (to 250000). > > Jan > > > Precision : 16-bit > > Sample Encoding: 16-bit Signed Integer PCM > > Endian Type : little > > Reverse Nibbles: no > > Reverse Bits : no > > > > rec INFO sox: Overwriting `test.wav' > > > > Output File : 'test.wav' > > Channels : 1 > > Sample Rate : 250000 > > Precision : 16-bit > > Sample Encoding: 16-bit Signed Integer PCM > > Endian Type : little > > Reverse Nibbles: no > > Reverse Bits : no > > Comment : 'Processed by SoX' > > > > rec INFO channels: has no effect in this configuration > > rec INFO sox: effects chain: input 250000Hz 1 channels > > rec INFO sox: effects chain: highpass 250000Hz 1 channels > > rec INFO sox: effects chain: vol 250000Hz 1 channels > > rec INFO sox: effects chain: spectrogram 250000Hz 1 channels > > rec INFO sox: effects chain: dither 250000Hz 1 channels > > rec INFO sox: effects chain: output 250000Hz 1 channels > > In:0.00% 00:00:04.33 [00:00:00.00] Out:1.07M [ | ] > > Clip:0 ^C > > Aborted. > > > ------------------------------------------------------------------------------ > _______________________________________________ > Sox-users mailing list > Sox...@li... > https://lists.sourceforge.net/lists/listinfo/sox-users |