I'm doing batch conversion of bit depth and sample rate with SoX using the following command:
sox -G $infile -b 16 $outfile rate 44100 dither
I'm using the -G flag to prevent clipping in the converted files, but for some files I still get the warning:
sox.exe WARN dither: dither clipped 1 samples; decrease volume?
Why might this still be happening?
Related
I have a heavily "overflowed" WAV file (samples written in float 32-bit format): instead of [-1.0,+1.0], the samples range goes as far as [-5.0,+5.0].
Using SoX to get raw PCM audio samples from WAV file:
sox --bits 32 --channels 1 --encoding floating-point --rate 48000 input.wav output.raw
I get warnings:
sox WARN sox: `input.wav' input clipped 1163400 samples
sox WARN sox: `output.raw' output clipped 605664 samples; decrease volume?
When I look into the output, I see the samples were clipped, and the range is [-1.0,+1.0] now. However, that is not what I want.
I would like to have exactly same output as input, just in different format (RAW instead of WAV). I need to use command line tool for the task. Is there a way to prevent SoX from doing the clipping?
I got the answer from the SoX mailing list.
The required behaviour isn't possible, however, in this specific case there is a workaround. Overriding input sample encoding as 32-bit signed integer instead of float, the values will be copied untouched; since the output is headerless, it doesn't matter what SoX thinks the samples are.
So, this works:
sox --bits 32 --channels 1 --encoding signed-integer --rate 48000 input.wav output.raw
I am trying to record 2 different microphones through Sox for one of my application. I am currently just testing on Mac terminal for the audio recording. However, I am only able to get audio through one microphone.
The sox command I am using is:
sox -b 32 -e unsigned-integer -r 96k -c 2 -d --clobber --buffer $((96000*2*10)) /tmp/soxrecording.wav trim 0 10
Which give me a good .wav file.
I have two different usb microphones which show up as 2 channel I/p each in Sound/System Preferences. I tried to do -c 4 with the sox command to record from both microphones.
sox -b 32 -e unsigned-integer -r 96k -c 4 -d --clobber --buffer $((96000*2*10)) /tmp/soxrecording.wav trim 0 10
However, I get a warning saying;
sox WARN formats: can't set 4 channels; using 2
And I can just get audio in from only one usb microphone. I have been trying to fiddle and understand what’s wrong but any hints would be really helpful.
You need to specify that you are using ALSA, then run two different SOX command and have to specify the hardware you use for each one.
Please refer to soc, play, rec man page, basically you may use the -d, --default-device parameter when starting your command to specify which device you want to use.
Something like (simplified):
sox -r 44100 -c 2 -e s -t alsa hw:4,0 -d
sox -r 44100 -c 2 -e s -t alsa hw:3,0 -d
This page and this page may also help you.
When I try to use sox to change the sample rate of a wav file I get a file of noise and garbage and the 2 following errors:
sox WARN rate: rate clipped 579 samples; decrease volume?
sox WARN dither: dither clipped 518 samples; decrease volume?
Although there are question marks there, I never get to answer them. They come up more as a status.
What I am starting with is a PCM file of my own making. The specs are:
16 bit signed
big endian
1 channel
44100 sample rate
I can import the file (0.wav) into Audacity and it's fine.
Then I convert the file into a wav file with the following line:
sox -r 44100 -e signed-integer -b 16 -c 1 0.raw 1.wav
I can import that file into Audacity and it also is fine.
But then when I try to change the sampling rate with:
sox 1.wav -r 16000 2.wav
If anyone knows what I'm doing wrong, or missing, I would appreciate it. Also I put up the original raw here: http://warptv.com/raw.html
This appears to be a problem of endian-ness. Your raw file is stored in big endian byte order, while WAV is, at least most of the time, little-endian.
This being the case you have to explicitly inform SoX about the endian-ness of your raw file, so this can be taken into account when converting. The appropriate switch for this is -B, changing your command into something like:
sox -r 44100 -e signed-integer -B -b 16 -c 1 0.raw 1.wav
With the raw file properly converted into a wav file the subsequent rate conversion as you attempted it should work as expected. At least it did for me.
Playing around a bit with Audacity it appears that it has some method of detecting (or guessing) the endian-ness of raw files that SoX lacks, and that this is the source of the discrepancy you found.
I am trying to convert some audio files to a raw format for machine learning and I need to ensure that clipping does not occur because I do not want it to contaminate my dataset.
This question has been asked before, but unfortunately the solutions did not work for me.
Several options have been proposed to help mitigate this problem.
The --norm option does not appear to work very well ...
$ for name in *.au; do sox --norm ${name} -c 1 -r 44100 --bits 8 ${name}.mono-sr41000-ss8.raw; done
sox WARN dither: dither clipped 1 samples; decrease volume?
sox WARN dither: dither clipped 1 samples; decrease volume?
sox WARN dither: dither clipped 1 samples; decrease volume?
sox WARN dither: dither clipped 1 samples; decrease volume?
sox WARN dither: dither clipped 1 samples; decrease volume?
sox WARN dither: dither clipped 1 samples; decrease volume?
sox WARN dither: dither clipped 1 samples; decrease volume?
sox WARN dither: dither clipped 1 samples; decrease volume?
sox WARN dither: dither clipped 1 samples; decrease volume?
sox WARN dither: dither clipped 1 samples; decrease volume?
sox WARN dither: dither clipped 1 samples; decrease volume?
sox WARN dither: dither clipped 1 samples; decrease volume?
sox WARN dither: dither clipped 1 samples; decrease volume?
sox WARN dither: dither clipped 1 samples; decrease volume?
sox WARN dither: dither clipped 1 samples; decrease volume?
sox WARN dither: dither clipped 1 samples; decrease volume?
The -v 0.99 option does not appear to work very well:
$ for name in *.au; do sox -v 0.99 ${name} -c 1 -r 44100 --bits 8 ${name}.mono-sr41000-ss8.raw; done
sox WARN rate: rate clipped 11 samples; decrease volume?
sox WARN dither: dither clipped 8 samples; decrease volume?
sox WARN rate: rate clipped 1 samples; decrease volume?
sox WARN dither: dither clipped 1 samples; decrease volume?
sox WARN rate: rate clipped 12 samples; decrease volume?
sox WARN dither: dither clipped 9 samples; decrease volume?
sox WARN rate: rate clipped 6 samples; decrease volume?
sox WARN dither: dither clipped 5 samples; decrease volume?
sox WARN rate: rate clipped 10 samples; decrease volume?
sox WARN dither: dither clipped 11 samples; decrease volume?
sox WARN rate: rate clipped 3 samples; decrease volume?
sox WARN dither: dither clipped 3 samples; decrease volume?
sox WARN rate: rate clipped 2 samples; decrease volume?
sox WARN dither: dither clipped 2 samples; decrease volume?
ubuntu#ip-10-217-154-40:~/data/genre/genres/blues$ for name in *.au;
The -G option seems to work best. However, even with this option some clipping occurs.
$ for name in *.au; do sox -G ${name} -c 1 -r 41000 --bits 8 ${name}.mono-sr41000-ss8.raw; done
sox WARN dither: dither clipped 1 samples; decrease volume?
sox WARN dither: dither clipped 2 samples; decrease volume?
sox WARN dither: dither clipped 1 samples; decrease volume?
Combining -G and --norm did worse than using either individually ...
$ for name in *.au; do sox -G --norm ${name} -c 1 -r 44100 --bits 8 ${name}.mono-sr41000-ss8.raw; done
sox WARN dither: dither clipped 1 samples; decrease volume?
sox WARN dither: dither clipped 1 samples; decrease volume?
sox WARN dither: dither clipped 1 samples; decrease volume?
sox WARN dither: dither clipped 1 samples; decrease volume?
sox WARN dither: dither clipped 1 samples; decrease volume?
sox WARN dither: dither clipped 1 samples; decrease volume?
sox WARN dither: dither clipped 1 samples; decrease volume?
sox WARN dither: dither clipped 1 samples; decrease volume?
sox WARN dither: dither clipped 1 samples; decrease volume?
sox WARN dither: dither clipped 2 samples; decrease volume?
sox WARN dither: dither clipped 1 samples; decrease volume?
sox WARN dither: dither clipped 1 samples; decrease volume?
sox WARN dither: dither clipped 1 samples; decrease volume?
sox WARN dither: dither clipped 1 samples; decrease volume?
sox WARN dither: dither clipped 1 samples; decrease volume?
sox WARN dither: dither clipped 1 samples; decrease volume?
sox WARN dither: dither clipped 1 samples; decrease volume?
sox WARN dither: dither clipped 1 samples; decrease volume?
sox WARN dither: dither clipped 1 samples; decrease volume?
UPDATE: Further reducing the volume seems to eliminate the clipping.
Is this the best solution?
$ for name in *.au; do sox -G -v 0.95 ${name} -c 1 -r 44100 --bits 8 ${name}.mono-sr41000-ss8.raw; done
sox WARN dither: dither clipped 1 samples; decrease volume?
sox WARN dither: dither clipped 1 samples; decrease volume?
$ for name in *.au; do sox -G -v 0.9 ${name} -c 1 -r 44100 --bits 8 ${name}.mono-sr41000-ss8.raw; done
I have a file, sound.au, which file describes as Sun/NeXT audo data: 8-bit ISDN mu-law, mono, 8000 Hz. I'd like to convert this to a WAV that file would describe as RIFF (little-endian) data, WAVE audio, Microsoft PCM, 16 bit, mono 8000 Hz. However, I cannot get the right set of arguments to make this conversion and see what it sounds like.
Has anyone performed this conversion or similar before? sox -t auto -w -s -r 8000 -c sound.au sound.wav gets me close, but it's G711 mu-law, not 16 bit PCM.
Thanks.
I don't have an .au file to try, but I suspect sox sound.au -e signed-integer sound.wav would work. You are only trying to change the encoding from u-law to PCM, right? sox should pick up all the necessary input info from the .au header. If it doesn't, maybe you need sox -t auto sound.au -e signed-integer sound.wav.