Step 4: Extracting Audio Data with Python

Processing has a library for dealing with audio called Minim, it is included with the more recent versions of Processing IDE.  Unfortunately, this library is set up for real time audio applications and does not appear give you an easy way of extracting all the data from an audio file at once (it makes you load it in small buffers piece by piece).  Since I could not find an easy way to load my wav files into Processing directly (although I'm sure this must be possible), I've been importing stereo audio in the wav format into Python using the wav library, adding the left and right channels together, centering the data around zero, and exporting the resulting array of int's (separated by commas) to a txt file.  Here is my wav to txt Python script (I'm running this in Python 2.5.4):

Once I create a text file, I can import the data into Processing and convert it into an STL.  I would like to streamline my code so that audio files (wav/mp3) can be loaded directly into Processing, but I have not found a solution yet, any suggestions would be appreciated!
<p>I received an email today from someone asking me about how far I managed to go with replicating Amanda's process, so I thought I'd share my experience in more details. </p><p>Note that this experience below occurred in December 2014.</p><p>My goal was to try print a 3mn song on 1 side of a 12 inches vinyl and see what is the best quality and output I could achieve, noticing that it has been already more than 2 years since Amanda did her project, so I assumed that the technology would have progressed rapidly.</p><p>Amanda's instructions and provided programs help you generate the binary file, then create a 3D model (STL file) for a one sided vinyl with that song on it (eq'd specifically for vinyl previously as per the video). At this stage, I don't know if you can even generate a two sided vinyl STL model but this didn't matter to me for that experience. </p><p>I downsampled the file to 12hz as per her initial instructions and default settings. The outcome was a file that was 700MB. Generating this file alone requires HUGE amount of processing power. Note that I'm using a Mac Book Pro with 16GB of ram, solid state drive and a very powerful processor. It was nevertheless a painful process for the computer to generate the file. See attached an image of the model. You'll note that the entire surface is not covered, which I couldn't quite figure out why. I assumed that if it did take the entire width, the grooves would be a be bigger and therefore more tolerant to the level of precision currently available via 3D printing.</p><p>I then tried changing the downsampling rate to something higher (I started at 24hz), so I could get to a quality closer to what I'm after (i.e. that can be released). It looked something like this:</p><p>Unfortunately, the file couldn't even get generated. My computer would hang permanently. That wasn't even trying 44hz which is what I was ideally after...</p><p>To note: the output STL file had dimensions for X and Y initially rendering in mm instead of inches for some reason so something to keep an eye out on if you try that technique using Amanda's program (unless it had to do with the program I used to render the shape - I then had to update the dimensions manually to the equivalent in mm).</p><p>I stuck to my 12hz downsampling rate then and contacted the most advanced 3D printing company in Melbourne I could find (3Dsystems.com). They had by very far the best machines I could find on the market for once off printing. I figured this would provide me already with a significant improvement of quality from what Amanda had produced.</p><p>The machine used was SLA Flex Printer with XHD 0.050 mm layers. Resolutions were uniform on all 3 axis, XYZ with all parts having an accuracy of 0.001 &ndash; 0.002 inch per inch of part dimension. This was by far the best printer I could find. The material used was 'Accura Xtreme'.</p><p>Unfortunately, the machine and vinyl would break before it could be fully printed, the file being far too large. Files are generraly a few dozens MB at most, and Amanda herself mentions that 300MB is already pushing it. </p><p>Doing some further research, I then thought that the model may be using a lot of polygons which are not required to print all the details. I therefore asked Amanda if she thought we could use a technique called decimation to remove useless polygons and therefore make the file lighter, but she confirmed that the program she created was pretty efficient. Considering how precise vinyls are in terms of geometry, this makes perfect sense. <br></p><div>Note that the price quoted to me was about US$250 for 1 copy (price goes down obviously as you order more). Copy of the quote attached.</div><div><p>As of today, there therefore doesn't seem to be a way to print even one single song in a decent quality. The song I used was just below 3mn and in mp3 format.</p><p>I'm not sure whether there are elements I could have tweaked to change the output (type of printer or material used, settings in the file), but it seemed that as of early 2015, we were still a long way to being able to 3D print vinyls from the comfort of our home, or as an alternative manufacturing process to the vinyl plants (which was the main goal of my investigation here). </p><p>If anyone has tried similar experiences and maybe had better outcomes, I'd love to hear about it.</p><p>Cheers, Charly</p></div>
<p>thanks for posting this, lots of good info here.</p>
<p>Hello Amanda!</p><p>I represent a national touring band that wants to talk with you about your 3D printed vinyl concept. They want to release plans for people to print a new song for record store day. I'd love to have a quick chat about how feasible this may be and if you'd ever be interested in working with us? Or perhaps recommending someone to work with as I'm sure you're very busy...All the best to you!</p><p>Vance Anderson<br>vanderson7@me.com</p>
<p>What a creative technology 3D printing. Btw, can I made iPhone with 3D printing machine?</p>
<p>This is incredible. I'm impressed at how far 3D printing has gone. Someday most of our items will be 3d printed, I assume. What do you think?</p>
<p>Hi Amanda, I just sent you an e-mail regarding a film shoot inquiry. Can you please check your gmail and let me know what you think? Thank you~</p>
The problem seems to be in the nature of the printer output design. I think a much simpler solution would be to develop a printer that printed a long line for the audio then use a separate device that rolled it into a record like a really short but very thick jelly roll. I don't know if my idea makes sense but basically you'd be printing and then rolling a line of sound into a record format. I don't know of any type of printer that does this though or if one could even be made. It just seems that printing it all at once as a single object is where the problem with audio quality is coming from.
<p>Thank you for all what they offer</p>
<p>I have just showed this to my cousin and the reaction was ... @#!</p>
<p>This is really impressive. Can someone make 10 of these for me? It's for an exclusive project with a world renouned artist, using an unreleased song. Let me know and thanks in advance!</p>
<p>This is so awesome ! I love innovative projects like this one.</p>
<p>Hi, Amanda, great project. Can you tell me how can i make a sound loop record?</p>
<p>Smells like teen spirit is a timeless song. And that record is so cool. Great job.</p>
<p>Very Good.....</p>
<p>This is such a cool program! But I am having trouble running the processing sketch. It says</p><p>&quot;No library found for unlekker.util</p><p>No library found for unlekker.modelbuilder</p><p>No library found for ec.util</p><p>Libraries must be installed in a folder named 'libraries' inside the 'sketchbook' folder.&quot;</p><p>I tried putting the files in a bunch of different folders but non of them seemed to work. Any thoughts?</p>
<p>I like your work </p>
<p>Hi, this is a really great tutorial but I ran into a problem when trying to find the &quot;wavtotxt&quot; file on Python. Since Python has updated I wondered if it had been removed or possibly i just couldn't find it. I would really like to know how you found it as I was hoping to use this as a part of a project.</p><p>Thanks</p>
<p>Hey Amanda,</p><p>This is a very cool project, with detailed instructions. I work for a Computer Science Dept. at a University, and one of our Media Studies classes would would like to do this with some audio they created, and were very excited when they discovered your instructable. We have an Ultimaker 2. Since the print bed is only 8&quot; I figured it would make more sense to print a 7&quot; - 45. Using your code isn't a problem, but I am having some problems with how the changes affect the audio. I've also be unable to determine what the dpi for the Ultimaker 2 is. I know it's capable of printing 20 micro layers, but I'm not sure what xy values you use to determine it, when it's not published. I've posted the top of my processing file below, and was hoping you could give me an idea of how to modify the audio and groove parameters.</p><p>On another note, the slicing software for the Ultrimaker displays in mm rather then inches (and doesn't convert, which is annoying). If I wanted to do all the calculations in mm would I just need to change the record dimensions at the top and the scaling factor (which you've set to 25400 micros per inch) near the bottom, or is there something I'm missing.</p><p>Thanks so much</p><p>//record parameters</p><p>float diameter = 6.9;//diameter of record in inches</p><p>float innerHole = 0.286;//diameter of center hole in inches</p><p>float innerRad = 2.125;//radius of innermost groove in inches</p><p>float outerRad = 3.31;//radius of outermost groove in inches</p><p>float recordHeight = 0.06;//height of top of record (inches)</p><p>int recordBottom = 0;//height of bottom of record</p><p>//audio parameters</p><p>float samplingRate = 44100;//(44.1khz audio initially)</p><p>float rpm = 45;//rev per min</p><p>float rateDivisor = 4;//how much we are downsampling by</p><p>//groove parameters</p><p>float amplitude = 24;//amplitude of signal (in 16 micron steps)</p><p>float bevel = 0.5;//bevelled groove edge</p><p>float grooveWidth = 2;//in 600dpi pixels</p><p>float depth = 6;//measured in 16 microns steps, depth of tops of wave in groove from uppermost surface of record</p><p>//printer parameters</p><p>float dpi = 600;//objet printer prints at 600 dpi</p><p>float micronsPerLayer = 20;//microns per vertical print layer</p>
<p>Hi,</p><p>the x/y resolution for the Ultimaker is going to be dependent on the thickness of the extruded plastic coming out the nozzle. I suspect an Ultimaker will probably be too low res to get anything interesting to print unfortunately - closer to 60dpi rather than 600. Maybe try the laser cut records?</p><p>http://www.instructables.com/id/Laser-Cut-Record/</p><p>You're right about converting to mm.</p>
<p>Very nice liked. I hope you the further development.</p>
Hi Amanda ! This is a really amazing work you made here ! Congratulation ! <br>I tried to make my own 3D model with processing but I have some trouble with step 10. &quot;Change the name of the import file in the Processing sketch to your txt file name: String filename = &quot;your_file_name_here.txt&quot;;&quot; <br> <br>Should we write &quot;String filename = &quot;your_file_name_here.txt&quot;;&quot; in the text editor of Processing or make file&gt;open and open the .txt file ? <br> <br>Thanks in advance for your advices !
cool, glad to hear you're messing with the code! I just changed that line to whatever the name of my file was. so if I had a file called daftpunk.txt, I changed the line to read:<br /><br />String filename = "daftpunk.txt";<br /><br />does that make sense?
<p>Hello Amanda - I understand this Question was answer 2 years ago - but here I am asking the same question. </p><p>I have created the &quot;myfile.txt&quot; file through Python programming. But now trying to &quot;import the data within 'myfile.txt' file&quot; into Processing, and then also where should I be typing &quot;String filename = &quot;myfile.txt&quot;; ... Everytime I run Processing, all I get is a Grey 'java' box appear with nothing happening?</p><p>Any suggestions you may have?</p>
<p>do you see processing printing something like "drawing groove 1 of 100"? sometimes it takes a while to process, let it sit for a few minutes.</p>
<p>I dont unfortunately. I have 16Gb of RAM to</p><p>I dragged and dropped the &quot;mytext.txt&quot; file into the Processing window.</p><p>Then it says down the bottom - &quot;One file added to sketch&quot;</p><p>Then I typed - String filename = &quot;myfile.text&quot;; into the White section of the Processing window</p><p>And hit Run.</p><p>All I see is a small grey Java Window, and I can then even edit the text in the Processing window, almost like it has stopped running.</p>
<p>This is the coolest shit ever! bravo</p>
<p>Dear Amanda, I'm sorry for my stupid answer...<br>I understand all the steps... <br>But I did understand how I can print the vinyl... in a generic 3D print shop?<br>Which file I have to bringh there?<br>Thank you so much.</p>
<p>Very nice liked. I hope you the further development.</p>
<p>It&rsquo;s really cool to kind of push the <br>technology and see what you can get out of it. I&rsquo;ve got <br> a bunch more that I want to do.</p><p>Thanks...</p>
<p>Hello Amanda!</p><p>I represent a band that wants to talk with you about your 3D printed vinyl concept. They want to release plans for people to print their new album. I'd love to have a quick chat about how feasible this may be and if you'd ever be interested in working with us? All the best to you.</p><p>Vance Anderson<br>vanderson7@me.com</p>
<p>Wow I never thought you could do this with laser printing. And you're right, the songs are easily recognisable. This is pure genius. The sound from your printed record actually sounds like an old school record. I mean you can actually create a record nowadays and you don't even need the same material as that of classic records! I'm truly impressed.</p>
<p>3D printing is amazing. It's the first time I see something like this. </p>
<p>I'm not sure that i understand this fully, but well done anyway</p>
<p>Just so i've got this right, we will be able to print our own vinyl's and add our own music to that vinyl? if that's right, then that is amazing!</p>
<p>Yes <a href="http://www.instructables.com/member/RobertGoldring/" rel="nofollow">RobertGoldring</a>, you are correct printing our own vinyl's, so exciting!</p>
<p>Hi Amanda, thanks a lot for this great tutorial and for sharing all the amazing experimental work you're doing. I've been getting my head around it all day and I'm hopefully very close to output the STL file to try 3D printing it next. I'm curious to see what audio quality/resolution 3D printers can output these days, in comparison to the time where you made your demos.</p><p>I was looking at the video and noticed that in Audacity, you invert the curve in the equalisation effect and then apply a low pass filter. However, none of these steps seem to be mentioned in point 7. </p><p>Are you able to explain what these steps are for and whether they are required?</p><p>Thanks in advance! Charly</p>
<p>yeah that was the riaa eq step, I made that video after I published this instructable. You can find more info about that step in this project:</p><p><a href="http://www.instructables.com/id/Laser-Cut-Record/">http://www.instructables.com/id/Laser-Cut-Record/</a></p><p>step 7</p>
<p>3D printing is just round the corner, this will be a bigger hit to the high street.</p>
I am thrilled at your enthusiasm and technical know-how. But I couldn't help but notice you don't seem to be aware of how phonographs apply the RIAA equalization curve to the signal prior to amplification. This would explain why you get so much Bass and nearly no Treble. (IMHO you haven't yet hit the physical printing resolution barrier yet.) You should try applying the inverse RIAA emphasis curve to your audio data prior to your current processing steps and see how it goes, this way when played back the deck itself will apply the RIAA emphasis to your &quot;pre-de-emphasized&quot; signal and hopefully the result is increased fidelity.
<p>She actually applies the RIAA (as well as invert the curve and apply a low pass filter) in the video but just doesn't mention it in step 7, and coincidentally I asked her why she was doing this just a few minutes ago, so the en</p>
yes, this was a little oversight on my part. I haven't had a chance to go back and print out a record with RIAA eq, but all my laser cut records are properly eq'ed: <br />http://www.instructables.com/id/Laser-Cut-Record/
<p>Finally, I can download my records from pirate bay and print them out. </p>
<p>This is pretty amazing! Just imagine the quality and posibillities a few years into the future.. </p>
I agree Julie - this is just the tip of the ice berg....it's a POC the next stage is to take this into production - and mash up the flat form factor grooved records of the past/present with the 3D possibilities of the present / Future....is love to explore further with any other enthusasts of music/tech

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Bio: I'm a grad student at the Center for Bits and Atoms at MIT Media Lab. Before that I worked at Instructables, writing code for ... More »
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