automatically trim audio files - audio

I'm trying to extract snippets (3-5 sec.) from a large collection of audio files.
I would like to do this with a shell script. I found basically nothing on the internet, so I'm asking here.
I'm also familiar with perl, php and java - I don't care what language will do, I just want to job done :)
Scenario: I got a large archive of audio files in very high resolution. I need to extract a very short snippet in low resolution for a preview (3 to 5 sec. is extremely short but that's what we need). Being a huge fan of shell scripting, I was hoping to automatize a process that extracts the snippet at RANDOM onset time... is it really too much to ask? :)
Thank you for your ideas!

You can use flash to automatically set lengths on the audio according to this blog:
http://help.adobe.com/en_US/FlashPlatform/reference/actionscript/3/flash/media/Sound.html
Hope it helps.

Related

Can FFMPEG or any other project detect an audio file contains only noises?

I have a batch of audio files which recording people's voice. But some of this audio files record only noises or microphone burst. I want to detect these files and jump over them while processing my program.
I'm not sure whether ffmpeg can do this. If yes, could you guys provide me a link of that method? If not, do you know if there is some other software can do this? Or do you have any solution or suggestion to this problem?
Thank you.
I would approach this by looking at peak values and duration. SOX is a program that allows shell scripting which could batch analyze this. There is a large user base and forum as well.
Here is a link to a forum topic discussing it's use on batch discovering peak values and outputting information to a .csv file.

speech-to-text .. .VOX files to text, is this possible?

a little background: I'm faced with converting 3000 IVR scripts for a new PBX & IVR.
Currently the voice scripts exist in .VOX format--AND..they're not 'written-out'/documented.
I humbly ask if anyone knows of a program, such that, I can dump the .vox file in the program and have it produce a text document. If the .vox format is a problem I could probably convert all of them to .wav or whatever.
Yes there are tons of apps/programs which do speech to text in real time, but I want to be able to "upload/dump" the recording into a program, and obtain text.
Can someone point me in the right direction?
Thank you in advance for any sort of comment/help.
SF
The problem is that you are hoping to perform generic natural language processing on low quality audio files. Low quality audio data significantly reduces the reliability of natural language processing software. Upsampling your audio files will not improve their content which means poor results even if you did have access to a natural language engine.
Your best bet is to work with a company that performs hybrid machine/human transcription and pay them for each transcriptions. Alternatively you could consider working with Amazon Mechanical Turk and buy some general purpose human effort to get these transcribed. In both of those cases it is likely that VOX files would not work, you would first need to convert them to WAV or MP3 files to make it easier for the third party to use off the shelf software to listen to the prompts.

AIFF files: strip initial "whitespace"

I have a folder full of AIFF files that have a little gap at the beginning where no sound is heard. How would I go about writing a script/tool that'd remove this gap?
Basically the files look like this in Audacity (I want to get only the selected part):
I can't really use Audacity because I have hundreds of the files so doing it by hand is not an option.
I don't care too much about the OS / language, as long as it works.
since you are asking on a programmer's website and have programming experience (peeked at your profile) -- if you look in the sources, you will see Audacity has some scripting support.
there are also commercial tools (e.g. batch processors) for this.
i wouldn't recommend getting your hands too dirty with this file format (i.e. writing a C program could easily take more time than doing it manually in the editor).
In the end it was just easier to hack up a quick C++ solution using libsndfile.
Feel free to steal it from https://github.com/houbysoft/short/blob/master/removeInitialSilence.cpp.

Finding audio peaks in video files

I have a bunch of video files that I want to process. I want to write a program that can find the audio peaks in each file and return the times where those peaks occurred.
I've looked for a lot of different APIs in different languages but couldn't get any of them to work. I am partial to php and java, so if anyone knows any good audio processing libraries in those languages that would be great! But really I don't care too much about the language. I will need to run this program on a cron.
Also, is it possible to use system calls to ffmpeg from within a script to accomplish this? Thanks in advance.
While I've only used this to work directly with audio files, the python wrapper around theechonest's audio analysis service can slurp in the audio from various video files. It uses ffmpegs shared libs to do this, though I find this wrapper much easier to work with via python then the command line.
Of particular interest within the api is echonest.video which is, to quote the docs:
Framework that turns video into silly putty.
I'd add a couple other helpful urls but apparently I can only add one since I don't have a reputation...
anyway, hopefully that's a helpful lead.

Free sound editor / converter?

I'm looking for something like paint.net or Gimp, but for audio files, and runs on windows.
Audacity is fantastic
As already mentioned, Audacity is fantastic. If you're looking to batch convert sound files at the command line, check out mencoder and (for MP3s only) LAME.
Audacity is painfully limited. If you are looking to do something a little more complicated. You should check out Reaper. It has a 60 day free trial and if you are still doing editing and recording after that long, the price to buy is extremely cheap when compared to other fully functional editing software. Pro Tools is crazy expensive.
Personally I use REAPER for "complex" tasks (tracking, mastering, batch processing) and Audacity for basic cutting/normalizing/exporting to MP3.
If you need free alternative for Audacity for basic mono or stereo file processing, you may try Wavosaur or other software that has realtime previews.
NCH Wavepad is also the best application for the audio. it's easy to understand
Reaper has always worked very well for me. It is free to download and try for 60 days and requires a cheap license after that (there are two different price options). Highly recommended.
Here is the website link:
http://www.reaper.fm/

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