BPM reading of a live recording?

[brassmonkey411]

Hi, I've recently been experimenting with mixing mp3's into vinyl with reasonable success. However, I've come across a problem with accurate beatmatching (human error basically) and was wondering if anyone has a good way to automatically read the bpm of the live audio input (what Audacity is recording)?

What I'm trying to achieve is this; if I can get the bpm of the output from my turntable & mixer setup, I can then mix in mp3s (that I already know the bpm of) via another piece of software (Traktor).

So does anyone know of any software/plugin/app that can recognise a usb audio input and that reads bpm automatically reasonably?


Cheers, Matt

[kozikowski]

<<<read the bpm of the live audio input>>>

You were fine until you got to the word "input." Even output is a problem because you need to select the audio on the timeline and apply the filter. Input is especially a problem because nobody wants the latency that extra processing would cause. That kills muti-dubbing where you play music to yourself.

You join a list of people that want Audacity to be a real time processor.

It's not.

Koz

[brassmonkey411]

Ahh, yes, i suppose latency would be a factor if audacity was the program doing the bpm calculations.

Another reason why I'm trying to work around the problem by looking for a separate program/app/plugin that can recognise a usb soundcard's output signal. Audacity recognises it but the program I need to recognise it (Traktor) will not (and yes, i should probably post this in Traktor's forum but I thought Audacity users may have some experience with this).

I agree that audacity should be a realtime processor, as most audio programs are now-a-days and the possibilities for additional features would increase ten-fold, but hey, can't complain about the price!

[kozikowski]

<<<a separate program/app/plugin that can recognise a usb soundcard's output signal.>>>

You mean like H.323 videoconferencing, Audacity, and VOIP at the same time? I've tried that. It's not pretty. After a failure, it leaves you staring at the screen wondering which one of the programs got the sound services because it's clearly not the one you're using.

"Wave your hand if you can hear me."

I've been known to write messages on a notepad in magic marker to the guy at the far end because the video worked.....

Koz

[brassmonkey411]

Well, not for video purposes, strictly audio.

Let me explain my setup again (see attatchment). I need to count the BPM of the signal that comes from the the mixer (EQ unit) into my laptop WHILE Audacity is recording it.

Does that make sense? Hopefully the picture helps.

[kozikowski]

<<<Well, not for video purposes, strictly audio.>>>

But nonetheless, that represents three audio programs all trying to stand on the audio services at the same time. We gave up, by the way. Those three programs can't coexist on the same computer. It leads to terrible audio and insanity.

I would stop trying to force your computer and Audacity to do things difficult or impossible and buy the appropriate mixer:

TMX-7744 Mixer with BEATCOUNTER! For clean crossovers!
Mixer, 3-channels Made by PRO EVIDENCE
With 2 LCD Displays and Beat-Counter!
The Disco-Mixer! The "TMX 7744" disposes next to 3 channels a BeatCounter
and specialized sound adjustments, which allow you to change from one to
another song whenever you want. By seeing the beats per minute on the LC
Display you can optionally adjust the speed of each song, so the crossover
gets more fluent. Perfect for Beginners and Pros.

Koz

[brassmonkey411]

<<<Those three programs can't coexist on the same computer.>>>

Well I can tell you now, I have Traktor and Audacity running together fine on my ibook (only 512mb ram too btw). Audacity records the master output signal from the mixer and Traktor can be run through a line-in channel on the mixer simultaneously. But yes, I do understand my computer is working harder than normal and any further applications would increase the load even more.

What I was looking for was perhaps a widget, a plugin for either app (Traktor or Audacity), or even a small app that ran in the background which calculated the bpm of the signal goin into the computers audio input in realtime (so anything running on Audacity probably wouldn't work).

I don't think its impossible, I just think it hasn't been done before, and with my lack of programming abilities it may not be done for a while, if at all.

I do agree with you about buying a mixer for this purpose, as I need to upgrade my current mixer I will be looking for one that has a bpm readout. I thought it may be worth seeing if I can use what I already have (e.g. my computer) to do what I need without spending extra cash.

Cheers for the input kozikowski.

[kozikowski]

<<<I don't think its impossible, I just think it hasn't been done before>>>

Or you just haven't found it yet, and if you do find it, it's going to turn out to only run in Windows XP.

It's one of the burdens we Mac folk have to bear.

http://www.bluechillies.com/details/45050.html

Koz

[brassmonkey411]

<<<Or you just haven't found it yet, and if you do find it, it's going to turn out to only run in Windows XP.>>>

True, that would be the usual story.

In saying that, there are an amazing number of programs for mac that claim to read BPMs. I have been looking at alot of these pieces of software, none of which seem to read live audio input in realtime, they all seem to only be able to read mp3s (as in all ready recorded and saved, not currently recording).

Thanks for your help tho, I think I'll just have to tuff it up and beatmatch by ear (twice as hard to keep in time when you can't physically touch the track like vinyl)