update default parameters + python updates

- by default ggwave will now output 32-bit float samples
- python samples no longer use numpy
- python test now decodes payload
- fix buffer overflow in receive.py example

bindings/python/README-tmpl.rst

@@ -134,7 +134,6 @@ Usage
 
     import ggwave
     import pyaudio
-    import numpy as np
 
     p = pyaudio.PyAudio()
 
@@ -142,8 +141,8 @@ Usage
     waveform = ggwave.encode("hello python", txProtocol = 1, volume = 20)
 
     print("Transmitting text 'hello python' ...")
-    stream = p.open(format=pyaudio.paInt16, channels=1, rate=48000, output=True, frames_per_buffer=4096)
+    stream = p.open(format=pyaudio.paFloat32, channels=1, rate=48000, output=True, frames_per_buffer=4096)
-    stream.write(np.array(waveform).astype(np.int16), len(waveform))
+    stream.write(waveform, len(waveform)//4)
     stream.stop_stream()
     stream.close()
 
@@ -165,7 +164,7 @@ Usage
 
     try:
         while True:
-            data = stream.read(1024)
+            data = stream.read(1024, exception_on_overflow=False)
             res = ggwave.decode(instance, data)
             if (not res is None):
                 try:

bindings/python/README.md

@@ -8,7 +8,7 @@ README.rst is not commited to git because it is generated from [README-tmpl.rst]
 ## Building
 
 Run `make build` to generate an extension module as .so file.
-You can test it then by importing it from python interpreter `import ggwave` and running `ggwave.testC(...)` (you have to be positioned in the directory where .so was built).
+You can test it then by importing it from python interpreter `import ggwave` and running `ggwave.encode('test')` (you have to be positioned in the directory where .so was built).
 This is useful for testing while developing.
 
 Run `make sdist` to create a source distribution, but not publish it - it is a tarball in dist/ that will be uploaded to pip on `publish`.

bindings/python/ggwave.pyx

@@ -3,7 +3,6 @@ cimport cython
 from cpython.mem cimport PyMem_Malloc, PyMem_Free
 
 import re
-import struct
 
 cimport cggwave
 
@@ -43,7 +42,7 @@ def encode(payload, txProtocolId = 1, volume = 10, instance = None):
     if (own):
         free(instance)
 
-    return struct.unpack("h"*n, output_bytes[0:2*n])
+    return output_bytes
 
 def decode(instance, waveform):
     """ Analyze and decode audio waveform to obtain original payload

examples/ggwave-py/receive.py

@@ -10,7 +10,7 @@ instance = ggwave.init()
 
 try:
     while True:
-        data = stream.read(1024)
+        data = stream.read(1024, exception_on_overflow=False)
         res = ggwave.decode(instance, data)
         if (not res is None):
             try:

examples/ggwave-py/send.py

@@ -1,6 +1,5 @@
 import ggwave
 import pyaudio
-import numpy as np
 
 p = pyaudio.PyAudio()
 
@@ -8,9 +7,8 @@ p = pyaudio.PyAudio()
 waveform = ggwave.encode("hello python", txProtocolId = 1, volume = 20)
 
 print("Transmitting text 'hello python' ...")
-stream = p.open(format=pyaudio.paInt16, channels=1, rate=48000, output=True, frames_per_buffer=4096)
+stream = p.open(format=pyaudio.paFloat32, channels=1, rate=48000, output=True, frames_per_buffer=4096)
-stream.write(np.array(waveform).astype(np.int16), len(waveform))
+stream.write(waveform, len(waveform)//4)
-stream.write(np.zeros(16*1024), 16*1024) # short silence at the end
 stream.stop_stream()
 stream.close()
 

src/ggwave.cpp

@@ -268,7 +268,7 @@ const GGWave::Parameters & GGWave::getDefaultParameters() {
         GGWave::kBaseSampleRate,
         GGWave::kDefaultSamplesPerFrame,
         GGWAVE_SAMPLE_FORMAT_F32,
-        GGWAVE_SAMPLE_FORMAT_I16
+        GGWAVE_SAMPLE_FORMAT_F32,
     };
 
     return result;

tests/test-ggwave.py

@@ -1,6 +1,15 @@
+import sys
 import ggwave
 
 instance = ggwave.init()
 
+payload = 'hello python'
+
 # generate audio waveform for string "hello python"
-waveform = ggwave.encode("hello python", txProtocolId = 1, volume = 20, instance = instance)
+waveform = ggwave.encode(payload, txProtocolId = 1, volume = 20, instance = instance)
+
+# decode the audio waveform back to text
+res = ggwave.decode(instance, waveform)
+
+if res != payload.encode():
+    sys.exit(1)