improved the integration of cython backend, and added test for it

Author: xserra

README.md

@@ -58,6 +58,23 @@ Run only smoke tests:
 
     python -m pytest -k smoke
 
+
+Cython backend
+--------------
+
+sms-tools includes a compiled Cython extension for selected core routines.
+When available, it is used automatically for better performance.
+If it cannot be imported, sms-tools falls back to pure-Python implementations
+with the same public behavior (typically slower).
+
+You can verify which backend is active at runtime:
+
+    python - <<'PY'
+    from smstools.models import utilFunctions as UF
+    print("Using Cython backend:", UF.UF_C is not None)
+    print("Backend module:", getattr(UF.UF_C, "__file__", None))
+    PY
+
 Test case summary:
 
 * `tests/test_api_contracts.py`: API/signature and output-shape contract checks for core model entry points.

sms_tools.egg-info/PKG-INFO

@@ -82,6 +82,15 @@ Run only smoke tests:
 
     python -m pytest -k smoke
 
+Test case summary:
+
+* `tests/test_api_contracts.py`: API/signature and output-shape contract checks for core model entry points.
+* `tests/test_errors.py`: error-handling contracts (invalid parameters and invalid I/O paths).
+* `tests/test_models_smoke.py`: fast smoke coverage for all analysis/synthesis model modules.
+* `tests/test_transformations_smoke.py`: fast smoke coverage for all transformation modules.
+* `tests/test_models_ground_truth.py`: algorithmic/ground-truth model tests on synthetic signals (frequency accuracy, additivity, and quality invariants).
+* `tests/test_transformations_ground_truth.py`: algorithmic/ground-truth transformation tests (scaling/morphing identity behavior and expected interpolation/attenuation trends).
+
 
 Jupyter Notebooks
 -------

sms_tools.egg-info/SOURCES.txt

@@ -31,6 +31,10 @@ smstools/transformations/stftTransformations.py
 smstools/transformations/stochasticTransformations.py
 tests/conftest.py
 tests/test_api_contracts.py
+tests/test_cython_vs_python.py
 tests/test_errors.py
+tests/test_models_ground_truth.py
 tests/test_models_smoke.py
+tests/test_multirate.py
+tests/test_transformations_ground_truth.py
 tests/test_transformations_smoke.py

smstools/models/utilFunctions.py

@@ -437,10 +437,12 @@ def sineSubtraction(x, N, H, sfreq, smag, sphase, fs):
     for l in range(L):
         xw = x[pin : pin + N] * w  # window the input sound
         X = fft(fftshift(xw))  # compute FFT
-        Yh = UF_C.genSpecSines(
-            N * sfreq[l, :] / fs, smag[l, :], sphase[l, :], N
-        )  # generate spec sines, cython version
-        # 		Yh = genSpecSines_p(N*sfreq[l,:]/fs, smag[l,:], sphase[l,:], N, fs)   # generate spec sines, python version
+        if UF_C is not None:
+            Yh = UF_C.genSpecSines(
+                N * sfreq[l, :] / fs, smag[l, :], sphase[l, :], N
+            )  # generate spec sines, cython version
+        else:
+            Yh = genSpecSines_p(sfreq[l, :], smag[l, :], sphase[l, :], N, fs)  # python fallback
         Xr = X - Yh  # subtract sines from original spectrum
         xrw = np.real(fftshift(ifft(Xr)))  # inverse FFT
         xr[pin : pin + N] += xrw * sw  # overlap-add
@@ -475,10 +477,12 @@ def stochasticResidualAnal(x, N, H, sfreq, smag, sphase, fs, stocf):
     for l in range(L):
         xw = x[pin : pin + N] * w  # window the input sound
         X = fft(fftshift(xw))  # compute FFT
-        Yh = UF_C.genSpecSines(
-            N * sfreq[l, :] / fs, smag[l, :], sphase[l, :], N
-        )  # generate spec sines, cython version
-        # 		Yh = genSpecSines_p(N*sfreq[l,:]/fs, smag[l,:], sphase[l,:], N, fs)   # generate spec sines, python version
+        if UF_C is not None:
+            Yh = UF_C.genSpecSines(
+                N * sfreq[l, :] / fs, smag[l, :], sphase[l, :], N
+            )  # generate spec sines, cython version
+        else:
+            Yh = genSpecSines_p(sfreq[l, :], smag[l, :], sphase[l, :], N, fs)  # python fallback
         Xr = X - Yh  # subtract sines from original spectrum
         mXr = 20 * np.log10(abs(Xr[:hN]))  # magnitude spectrum of residual
         mXrenv = resample(