Processing Forum

Retrieving samples from an audio file at arbitrary times, i.e., NOT synced with playback

[0 Replies]
- 16-May-2011 12:01 PM
- Forum: Contributed Library Questions
Hi there,

I'm interested in doing some audio visualization in Processing. For my application I need to be able to access large arrays of contiguous audio samples. For instance, I might need all the samples between two specific times in a file. Ultimately I'll be windowing these samples and sending them to an analysis algorithm.

To state this in code, I'm looking for a function like this:
1. float[] samples = audioFile.getSamples(startTime, endTime);
I've looked at using Minim, but as far as I can tell, Mimim's focus is a bit different. Minim can give me access to the samples that are being played *right now*, e.g. by attaching a "listener" to an AudioPlayer, but this doesn't meet my needs. I don't want the samples that happen to be playing whenever the draw loop decides to execute. I want the samples at specific times that I specify.
Does anyone know how I might be able to get at this sort of data?

If there's a way to do this through existing Minim functions, so much the better. If I'll need to hack Minim, or use another library all together, any advice on where to start would be much appreciated.

Many thanks, :)

D.

Writing 3D text with PGraphicsPDF: "vertex(x, y, u, v) is not available with this renderer."

[4 Replies]
- 04-Nov-2010 11:00 AM
- Forum: Core Library Questions
I'm trying to produce a PDF that contains scaled and rotated text. The text shows up on the screen, but doesn't appear in the PDF. I get a message in the console -- "vertex(x, y, u, v) is not available with this renderer" -- that I haven't seen elsewhere in the forums.

I'm attaching a minimal sketch.

Does anyone have any idea what the problem is & how to fix it?

Many thanks,

Dave
2. import processing.core.*;
4. import processing.pdf.PGraphicsPDF;
7. float rotx;
8. float roty;
9. boolean record;
10. PFont font;
12. void setup() {
13. size(400, 450, P3D);
15. font = createFont("Arial", 100);
17. rotx= -0.27460164f;
18. roty = -2.2146025f;
20. record = true; // print the first frame
21. }
23. void draw() {
25. if (record) {
26. System.out.println("Writing to PDF...\n");
27. PGraphics pdf = beginRaw(PDF, "output.pdf");
28. //pdf.hint(ENABLE_NATIVE_FONTS);
29. //for(String s : PGraphicsPDF.listFonts()) System.out.println(s);
30. //pdf.textMode(SHAPE);
31. pdf.textFont(font);
32. }
34. background(255);
36. translate(width/2.0f, height/2.0f, -100);
37. rotateX(rotx);
38. rotateY(roty);
39. scale(2);
41. pushStyle();
43. // draw axes
44. stroke(255,0,0);
45. line(-100,0,0,100,0,0);
46. stroke(0,255,0);
47. line(0,-100,0,0,100,0);
48. stroke(0,0,255);
49. line(0,0,-100,0,0,100);
51. popStyle();
53. fill(0);
55. translate(50,0,0);
56. rotate(PI/2,0,1,0);
57. String s = "Text";
58. text(s,0,0,0);
60. if (record) {
61. endRaw();
62. record = false;
63. }
64. }
67. // Hit 'r' to record a single frame
68. public void keyPressed() {
69. if (key == 'r') {
70. record = true;
71. }
72. }

How to write to Preferences.txt

[4 Replies]
- 23-Sep-2010 08:21 PM
- Forum: Library and Tool Development
Hi,

Can anyone advise me on how to write new settings into Preferences.txt? A Tool I'm working on needs to remember a variable from one launch to the next.

I've tried using the following code to append a line to the preferences file:
1. File prefFile = Base.getSettingsFile( "Preferences.txt" );
  
  PrintWriter prefWriter = null ;
  
  try {
  
  prefWriter = new PrintWriter( new FileWriter(prefFile, true ));
  
  prefWriter.println( "newSetting = value" );
  
  prefWriter.close();
  
  } catch (IOException e) {
  
  }
This works temporarily. When I view preferences.txt immediately after this code executes my new Setting shows up. Once I close the Processing app, though, my new Setting is erased from the file.

Am I doing something wrong? Is there some other function I should be using to add to Settings?

Or am I taking the entirely wrong approach?

Thanks in advance,

D.

Writing a Tool that depends on a Library

[2 Replies]
- 31-Aug-2010 10:43 PM
- Forum: Library and Tool Development
I've just written a processing library, and now I'm trying to write a tool that depends on the library (i.e., the tool uses some of the classes in the library's .jar file). I'm having trouble. The tool compiles successfully, but problems come up when I try to launch Processing. The Tool complains that it can't find the library classes (it throws a ClassNotFoundException).

I've tried including this line in build.properties --

classpath.libraries.location=${sketchbook.location}/libraries

-- but that doesn't seem to help.

How can I tell the Tool to look for classes in Processing's library folder?

Any suggestions?

Apologies if I'm forgetting to do something obvious. I'm new-ish to Java.

Many thanks,

D.

Drawing to a PImage

[3 Replies]
- 01-Aug-2010 05:32 PM
- Forum: Programming Questions
I'm trying to write a program that draws images. That is, I want to use processing commands like line(...) and rect(...), but instead of having the resulting lines and shapes show up directly on the screen, I want them to appear in a PImage that I can then manipulate. Is this possible? If so, how?

Thanks in advance,

D.

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