Batch process audio files?

[Soldermizer]

I want a PC based tool that allows automation of editing sound files (wav, mp3, etc.) For example, I learned here (or audio asylum) that you can rip a CD, use Audacity to make a track filtered to have low bass (say, < 80 Hz), then lower pitch 50% results in really low synthesized bass (20-40 Hz), mix with original, and viola, a bassier song. I'm familiar with two tools that can do this (Exact Audio Copy and Audacity, both good and FREE!) But is it possible to automate such an operation? It's not hard to do, but I have roughly 30,000 songs and would rather the machine do it

P.S. I am well aware of hardware (e.g. DBX subharmonic symths) and probably there is software to do this as well; I would like to find software solution. I will even pay if I must

 

[phofman]

SoX - Sound eXchange | HomePage

 

[sinski]

dBpoweramp Batch converter

 

[Michael Bean]

use Audacity to make a track filtered to have low bass (say, < 80 Hz), then lower pitch 50% results in really low synthesized bass (20-40 Hz), mix with original, and viola, a bassier song.

But in doing that, don't you lose the octave between 40Hz and 80hz?

Mike

 

[Soldermizer]

No, what I do is: copy original stereo track, paste to new stereo track. On this copy, you run a EQ to (usually) filter everything >80 Hz. Then use pitch change -50% to drop everything an octave. "Mix and render" with original track, possibly adjusting levels so that new bass + original match up (and prevent clipping). Export to WAV and listen. Works pretty well. Just not automatisch.

 

[Soldermizer]

Mr. Phofman: thanks a lot, you had me "hacking" all evening long
My script programming is very rusty. Nevertheless I have a basic script working. The potential to ruin my entire music collection while I sleep is nearly within my power
I will need to find the best biquad (steep filter) but that is part of the fun.
If you really are in Pilsen, please enjoy your Pils. One of the finest things in Europe!

 

[phofman]

I am glad you enjoy sox (and the beer too )

For mp3 you will have to find a lame-enabled windows build somewhere on internet, officially sox binaries cannot be distributed with mp3 support compiled-in due to MP3 licensing conditions. But you probably know that.

Good luck.

 

[Soldermizer]

Thanks for all the pointers. I have found the mp3-enabled version of SOX. I have a working batch converter. OK, I found the magic bandpass command:

sinc -t 1 40-80

If anyone wants my code, I'll be glad to post it. It is very short. Just like most types of wisdom, it is my experience that deriving even a simple script takes several hours to get close to what you wanted, and only a few lines to write it down

 

[jeff mai]

For Windows users this may help:

Batchenc

 

[Soldermizer]

Hmmm....my last post didn't post apparently. Working on little else for past day I've made good progress. SOX in the ancient Unix tradition, is very powerful and very cryptic. So far, I've tweaked my script as follows: seem to get best results by dropping everything an octave first, then cutting out what I want (now it's 20-60 Hz). I even figured out how to make an mp3 output to high(er) quality. I prefer 160 Kbps.

 

[Soldermizer]

SOX definitely is a great processing tool. I looked over at Audio Asylum for old posts and most of them deal with resampling. Does anyone know of a forum where people share audio processing they are doing with SOX (scripts, etc.)? This would probably be more specialized than DIY Audio usually does, but somewhere...?

 

[jeff mai]

Does anyone know of a forum where people share audio processing they are doing with SOX (scripts, etc.)? This would probably be more specialized than DIY Audio usually does, but somewhere...?

Have you looked around here?

Hydrogenaudio Forums (Powered by Invision Power Board)

 

[phofman]

Perhaps the sox-users mailing list, e.g. SoX | Mailing List Archive ?

 

[Soldermizer]

I poked around on Hydrogenaudio, searched for threads having "SOX bass" and nothing interesting came up. Just looked in sox-users and nothing came up for several likely searches. I'm amazed that no one has used SOX for bass synthesis (or more accurately, that I don't know of it yet.) For future reference, here are some magic words that expand the dynamic range by 30%, then synthesize bass from 20-60 Hz:

REM Expand the dynamic range by about 30%
sox -S %%A TEMP1.wav compand 0,.020 -inf,0,-100,-130
REM Drop pitch by one octave; sinc filter between 20-60 Hz
sox -S TEMP1.WAV TEMP2.WAV pitch -1200 sinc -t 20 20-60
REM combine expanded source with synthesized bass and output:
sox -S -m -v 1 TEMP1.WAV -v 1 TEMP2.WAV -C 160.0 "CONVERTED/%%~nxA" rate -s -L -v 44100