I need to split mp3 file into slices TIME sec each. I've tried mp3splt, but it doesn't work for me if output is less than 1 minute.
Is it possible do do with:
sox file_in.mp3 file_out.mp3 trim START LENGTH
When I don't know mp3 file LENGTH
You can run SoX like this:
sox file_in.mp3 file_out.mp3 trim 0 15 : newfile : restart
It will create a series of files with a 15-second chunk of the audio each. (Obviously, you may specify a value other than 15.) There is no need to know the total length.
Note that SoX, unlike mp3splt, will decode and reencode the audio (see generation loss). You should make sure to use at least SoX 14.4.0 because previous versions had a bug where audio got lost between chunks.
There are two use case trim in sox:
sox file_in.mp3 file_out.mp3 trim START LENGTH
and
sox file_in.mp3 file_out.mp3 trim START =END
In last example you need to know the END position instead of LENGTH
Related
I use the following code to trim, pipe and concatenate my audio files.
sox "|sox audio.wav -p trim 0.000 =15.000" "|sox audio.wav -p trim 15.000" concatenated.wav
One would expect that concatenated.wav will sound identical compared to a.wav.
However, when both files are played simultaneously together, there is a distinct audio shift on concatenated.wav.
Normally this error is acceptable as it is in the milliseconds range. However, as the number of pipe increases (say more than 100), the amount of audio shift increases substantially.
What is the correct method to trim, pipe and concatenate audio files using SoX to prevent this error?
Edit 1: Samples was used instead of milliseconds. Still met the same problem.
The following code was used:
sox "|sox audio.wav -p trim 0s =661500s" "|sox audio.wav -p trim 661500s" concatenated.wav
Wave file sample rate is 44100hz. Sample size is 16 bit.
SoX 14-4-2 was used.
The problem is that sox may lose a few samples at the cut point of the trim command.
I had a similar problem and solved it by cutting not by milliseconds, but by samples, which of course depend on the sample rate.
If your cutpoints are multiples of the used sample rate, you will no longer lose samples and the combined parts will have the exact same length as the original.
My goal is to get the parts of audio file that contains non-noise sounds by using SoX. I have read the effects of SoX and found noisered and silence which I consider helpful. The problem is that I have not found command that can trim the audio file based on the silent pauses in it.
I believe that what you are looking for can be achieved with a sox silence command. It allows you to remove the silence from any part of the audio given a threshold, durations above it, etc.
For a detailed manual please refer to the sox webpage, the silence section is very well written.
If you want to split at silence and not to "squeeze" everything together, then you might want to try something like:
sox input.wav slice.wav silence 1 1.0 2% 1 3.0 2% : newfile : restart
Parameters are:
input.wav - input audio file
slice.wav - output audio files name (numbers will be appended to each slice)
silence - effect name
1 1.0 2% - above_periods, duration, threshold
1 3.0 2% - below_periods, duration, threshold
I am concatenating multiple (max 25) audio files using SoX with
sox first.mp3 second.mp3 third.mp3 result.mp3
which does what it is supposed to; concatenates given files into one file. But unfortunately there is a small time-gap between those files in result.mp3. Is there a way to remove this gap?
I am creating first.mp3, second.mp3 and so on before concatenating them by merging multiple audios(same length/format/rate):
sox -m drums.mp3 bass.mp3 guitar.mp3 first.mp3
How can I check and assure that there is no time-gap added on all those files? (merged and concatenated)
I need to achieve a seamless playback of all the concatenated files (when playing them in browser one after another it works ok).
Thank you for any help.
EDIT:
The exact example (without real file-names) of a command I am running is now:
sox "|sox -m file1.mp3 file2.mp3 file3.mp3 file4.mp3 -p" "|sox -m file1.mp3 file6.mp3 file7.mp3 -p" "|sox -m file5.mp3 file6.mp3 file4.mp3 -p" "|sox -m file0.mp3 file2.mp3 file9.mp3 -p" "|sox -m file1.mp3 file15.mp3 file4.mp3 -p" result.mp3
This merges files and pipes them directly into concatenation command. The resulting mp3 (result.mp3) has an ever so slight delay between concatenated files. Any ideas really appreciated.
The best — though least helpful — way to do this is not to use MP3 files as your source files. WAV, FLAC or M4A files don't have this problem.
MP3s aren't made up of fixed-rate samples, so cropping out a section of an arbitrary length will not work as you expect. Unless the encoder was smart (like lame), there will often be a gap at the start or end of the MP3 file's audio. I did a test with a sample 0.98s long (which is precisely 73½ CDDA frames, and many MP3 encoders use frames for minimum sample lengths). I then encoded the sample with three different MP3 encoders (lame, sox, and the ancient shine), then decoded those files with three decoders (lame, sox, and madplay). Here's how the sample lengths compare to the original:
Enc.→Dec. Length Samples CDDA Frames
----------------- --------- ------- -----------
shine→lame 0.95" 42095 71.5901
shine→madplay 0.97" 42624 72.4898
shine→sox 0.97" 42624 72.4898
lame→lame 0.98" 43218 73.5000
*Original 0.98" 43218 73.5000
sox→sox 0.99" 43776 74.4490
sox→lame 1.01" 44399 75.5085
lame→madplay 1.02" 44928 76.4082
lame→sox 1.02" 44928 76.4082
sox→madplay 1.02" 44928 76.4082
Only the file encoded and decoded by lame ended up the same length (mostly because lame inserts a length tag to correct for these too-short samples, and knows how to decode it). Everything encoded by sox ended up with a tiny gap, no matter what decoder I used. So joining the files will result in tiny clicks.
Your browser is likely mixing and overlapping the source files very slightly so you don't hear the clicks. Gapless playback is hard to do correctly.
This is my guess for your issue:
sox does not add time gap during concatenation,
however it add time-gap in other operations, for instance if you do a conversion before the concatenation.
To find out what happens I suggest you to check all durations of your files at each time (you can use soxi for instance) to see what's going on.
If it doesn't work (the time-gap is added during concatenation), let me please do another guess:
Sox add time gap because your samples at the beginning or at the end of the file are not close to zero.
To solve this, you could use very short fade-in an fade-out on you files.
Moreover, to force sox to output files with a well-defined length, you could use the trim parameter like this:
sox filein.mp3 trim 0 duration fileout.mp3
First you need really check if the start and the end of your files has no silences, i dont know if sox can do it but you need check the energy(rms, dB) of the start and end audio signals and cut start and end silence, to join audio files without gaps you need apply one window function in your signal to works like a fadein/fadeout and then crossfade the beginning of one with the end of the other.
sox provide a splice function to crossfade:
splice [−h|−t|−q] { position[,excess[,leeway]] }
Splice together audio sections. This effect provides two things over simple audio concatenation: a (usually short) cross-fade is applied at the join, and a wave similarity comparison is made to help determine the best place at which to make the join.
Check Documentation here
I am trying to output the begin-timestamps of periods of silence (since there is background noise, by silence I mean a threshold) in a given audio file. Eventually, I want to split the audio file into smaller audio files, given these timestamps. It is important that no part of the original file be discarded.
I tried
sox in.wav out.wav silence 1 0.5 1% 1 2.0 1% : newfile : restart
(courtesy http://digitalcardboard.com/blog/2009/08/25/the-sox-of-silence/)
Although, it somewhat did the job, it also trimmed and discarded the periods of silence, which I do not want happening.
Is 'silence' the right option, or is there a simpler way to accomplish what I need to do?
Thanks.
Unfortunately not Sox, but ffmpeg has a silencedetect filter that does exactly what you're looking for:
ffmpeg -i in.wav -af silencedetect=noise=-50dB:d=1 -f null -
(detecting threshold of -50db, for a minimum of 1 seconds, cribbed from the ffmpeg documentation)
...this would print a result like this:
Press [q] to stop, [?] for help
[silencedetect # 0x7ff2ba5168a0] silence_start: 264.718
[silencedetect # 0x7ff2ba5168a0] silence_end: 265.744 | silence_duration: 1.02612
size=N/A time=00:04:29.53 bitrate=N/A
There is (currently, at least) no way to make the silence effect output the position where it has detected silence, or to retain all of the silent audio.
If you are able to recompile SoX yourself, you could add an output statement yourself to find out about the cut positions, then use trim in a separate invocation to split the file. With the stock version, you are out of luck.
SoX can easily give you the timestamps of the actual silences in a text file. Not periods of silence though, but you can calculate those with a simple script
.dat Text Data files. These files contain a textual representation of the sample data. There is one line at the beginning that contains the sample
rate, and one line that contains the number of channels. Subsequent lines contain two or more numeric data intems: the time since the beginning of
the first sample and the sample value for each channel.
Values are normalized so that the maximum and minimum are 1 and -1. This file format can be used to create data files for external programs such as
FFT analysers or graph routines. SoX can also convert a file in this format back into one of the other file formats.
Example containing only 2 stereo samples of silence:
; Sample Rate 8012
; Channels 2
0 0 0
0.00012481278 0 0
So you can do sox in.wav out.dat, then parse the text file and consider a silence a sequence of rows with a value close to 0 (depending on your threshold)
necroposting:
You can run a separate script that iterates all of the sox output files, (for f in *.wav), and use the command; soxi -D $f to obtain the DURATION of the sound clip.
Then, get the system time in seconds date "+%s", then subtract to find the time the recording starts.
Using Sox, how do I shorten an audio file by 5 seconds, trimming from the end?
For example, this is how to trim a file from the beginning:
sox input output trim 5000
This is how to add 5 seconds of silence to the end:
sox input output pad 0 5000
The syntax is sox input output trim <start> <duration>
e.g. sox input.wav output.wav trim 0 00:35 will output the first 35 seconds into output.wav.
(you can know what the length is using sox input -n stat)
From the SoX documentation on the trim command:
Cuts portions out of the audio. Any number of positions may be given; audio is not sent to the output until the first position is reached. The effect then alternates between copying and discarding audio at each position. Using a value of 0 for the first position parameter allows copying from the beginning of the audio.
For example,
sox infile outfile trim 0 10
will copy the first ten seconds, while
play infile trim 12:34 =15:00 -2:00
and
play infile trim 12:34 2:26 -2:00
will both play from 12 minutes 34 seconds into the audio up to 15 minutes into the audio (i.e. 2 minutes and 26 seconds long), then resume playing two minutes before the end of audio.
Per dpwe's comment, the position values are interpreted as being relative to the previous position, unless they start with = (in which case they are relative to the start of the file) or - (in which case they are relative to the end of the file).
So, trimming five seconds off the end would be sox input output trim 0 -5
Above command is wrong, it will get you last 5 seconds only. You actually need to use:
sox input output reverse trim 5 reverse
which will cut 5 seconds from end of the file.
I'm new to SoX but have noticed this page frequently shows up in search results for audio trimming and will be seen by many trying to do similar things.
As such I wanted to provide what I have found to be the best solution personally.
I experienced the same 'click' at file end which John Smith Optional had mentioned. This suggested a brief fade out could remove any glitching artefacts as the audio finishes and sure enough it works. It's acceptance of a negative value for the fadeout position parameter to indicate the time before the end of audio is the key.
So I can see no better way to achieve the OP's aim than this:
sox full_length.wav trimmed.wav fade 0 -5 0.01
Parameter 1 is '0' so there is no fade in.
Parameter 2 removes the last 5 seconds
Parameter 3 uses a 10ms fade