-
Notifications
You must be signed in to change notification settings - Fork 6
Commit
This commit does not belong to any branch on this repository, and may belong to a fork outside of the repository.
Add base64 dit/dah sound generation script
- Loading branch information
1 parent
ccbc7e3
commit 1c2cf0a
Showing
2 changed files
with
92 additions
and
2 deletions.
There are no files selected for viewing
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,71 @@ | ||
| # This file generates the morse code dits and dahs sounds | ||
| # as base 64 encoded strings for use in the HTML5/Javsacript page | ||
| import base64 | ||
| from io import BytesIO | ||
| import numpy as np | ||
| import struct | ||
| import wave | ||
|
|
||
| # Code based off of this answer http://stackoverflow.com/a/33246354/2574639 | ||
| def sine_samples(freq, duration, framerate=44100, amplitude=0.5): | ||
| # Get (sample rate * duration) samples on X axis | ||
| # (between freq oscillations of 2pi) | ||
| X = (2*np.pi*freq/framerate) * np.arange(framerate*duration) | ||
|
|
||
| # Get sine values for these X axis samples (as integers) | ||
| S = (amplitude*32767*np.sin(X)).astype(int) | ||
|
|
||
| # Pack integers as signed "short" integers (-32767 to 32767) | ||
| as_packed_bytes = (map(lambda v:struct.pack('h',v), S)) | ||
| return as_packed_bytes | ||
|
|
||
| def output_wave(path, frames, framerate=44100): | ||
| with wave.open(path,'w') as output: | ||
| # Set parameters for output WAV file | ||
| # (1 channel, 2 bytes per sample, framerate, num frames, no compression, no compression) | ||
| output.setparams((1,2,framerate,0,'NONE','not compressed')) | ||
| output.writeframes(frames) | ||
|
|
||
| def output_sound(path, freq, dur, framerate=44100): | ||
| # join the packed bytes into a single bytes frame | ||
| frames = b''.join(sine_samples(freq,dur, framerate)) | ||
|
|
||
| # output frames to file | ||
| output_wave(path, frames, framerate) | ||
|
|
||
| def output_base64(freq, dur, framerate=44100): | ||
| """Return Base 64 encoded string of wave file""" | ||
| data_buffer = BytesIO() | ||
| output_sound(data_buffer, freq, dur, framerate) | ||
| return base64.b64encode(data_buffer.getvalue()) | ||
|
|
||
|
|
||
| # We'll use a low 4.41khz framerate for our audio to reduce the string length | ||
| framerate = 4410 | ||
| beep_freq = 800 # Hz | ||
| beep_duration = 0.1 # seconds | ||
|
|
||
| # # We could just write a wav file directly | ||
| # output_sound('dit.wav', 800, beep_duration, framerate) | ||
| # output_sound('dah.wav', 800, beep_duration*3, framerate) | ||
|
|
||
| # Instead of writing to file, and then reading from file to convert to base64 | ||
| # We'll keep it in memory using ByteIO | ||
|
|
||
| dit_b64 = output_base64(beep_freq, beep_duration, framerate) | ||
| dah_b64 = output_base64(beep_freq, beep_duration*3, framerate) | ||
| # Write to text file for usage with html5 web audio | ||
| with open('dit_base64.txt','w') as f: | ||
| f.write(dit_b64.decode('utf8')) | ||
| with open('dah_base64.txt','w') as f: | ||
| f.write(dah_b64.decode('utf8')) | ||
|
|
||
| # Alternatively print to console | ||
| print("Dit (%d):\n%s" % (len(dit_b64), dit_b64.decode('utf8'))) | ||
| print("Dah (%d):\n%s" % (len(dah_b64), dah_b64.decode('utf8'))) | ||
|
|
||
| # These base64 strings can be directly used to make sound | ||
| # in an HTML5 page via javascript using: | ||
| # | ||
| # var snd = new Audio("data:audio/wav;base64,<base64_encoded_wav_string>") | ||
| # snd.play() |