modified tests for speed and tempo

test/test_sox_effects.py

@@ -57,7 +57,7 @@ class Test_SoxEffectsChain(unittest.TestCase):
         x, sr = E.sox_build_flow_effects()
         # Note: the output was encoded into ulaw because the
         #       number of unique values in the output is less than 256.
-        self.assertLess(x.unique().size(0), 2**8)
+        self.assertLess(x.unique().size(0), 2**8 + 1)
         self.assertEqual(x.numel(), si_in.length)
 
     def test_band_chorus(self):
@@ -110,7 +110,7 @@ class Test_SoxEffectsChain(unittest.TestCase):
         E.clear_chain()
         self.assertLess(x.abs().max().item(), 1.)
 
-    def test_tempo(self):
+    def test_tempo_or_speed(self):
         tempo = .8
         si, _ = torchaudio.info(self.test_filepath)
         E = torchaudio.sox_effects.SoxEffectsChain()
@@ -118,7 +118,30 @@ class Test_SoxEffectsChain(unittest.TestCase):
         E.append_effect_to_chain("tempo", ["-s", tempo])
         x, sr = E.sox_build_flow_effects()
         # check if effect worked
-        self.assertEqual(x.size(1), int((si.length / si.channels) / tempo))
+        self.assertAlmostEqual(x.size(1), math.ceil((si.length / si.channels) / tempo), delta=1)
+        # tempo > 1
+        E.clear_chain()
+        tempo = 1.2
+        E.append_effect_to_chain("tempo", ["-s", tempo])
+        x, sr = E.sox_build_flow_effects()
+        # check if effect worked
+        self.assertAlmostEqual(x.size(1), math.ceil((si.length / si.channels) / tempo), delta=1)
+        # tempo > 1
+        E.clear_chain()
+        speed = 1.2
+        E.append_effect_to_chain("speed", [speed])
+        E.append_effect_to_chain("rate", [si.rate])
+        x, sr = E.sox_build_flow_effects()
+        # check if effect worked
+        self.assertAlmostEqual(x.size(1), math.ceil((si.length / si.channels) / speed), delta=1)
+        # speed < 1
+        E.clear_chain()
+        speed = 0.8
+        E.append_effect_to_chain("speed", [speed])
+        E.append_effect_to_chain("rate", [si.rate])
+        x, sr = E.sox_build_flow_effects()
+        # check if effect worked
+        self.assertAlmostEqual(x.size(1), math.ceil((si.length / si.channels) / speed), delta=1)
 
     def test_trim(self):
         x_orig, _ = torchaudio.load(self.test_filepath)

torchaudio/torch_sox.cpp

@@ -295,6 +295,7 @@ int build_flow_effects(const std::string& file_name,
   for(SoxEffect tae : pyeffs) {
     if(tae.ename == "no_effects") break;
     e = sox_create_effect(sox_find_effect(tae.ename.c_str()));
+    e->global_info->global_info->verbosity = 1;
     if(tae.eopts[0] == "") {
       sox_effect_options(e, 0, nullptr);
     } else {
@@ -354,6 +355,8 @@ int build_flow_effects(const std::string& file_name,
   // Could be related to: https://sourceforge.net/p/sox/bugs/314/
   int nc, ns;
   if (output->signal.length == 0) {
+    // sometimes interm_signal length is extremely large, but the buffer_size
+    // is double the length of the output signal
     if (interm_signal.length > (buffer_size * 10)) {
       ns = buffer_size / 2;
     } else {
@@ -366,24 +369,24 @@ int build_flow_effects(const std::string& file_name,
   }
   otensor.resize_({ns/nc, nc});
   otensor = otensor.contiguous();
+
   input = sox_open_mem_read(buffer, buffer_size, target_signal, target_encoding, file_type);
   std::vector<sox_sample_t> samples(buffer_size);
   const int64_t samples_read = sox_read(input, samples.data(), buffer_size);
-  // buffer size is twice signal length, but half the buffer is empty so correct
-  // number of samples should be read
   assert(samples_read != nc * ns && samples_read != 0);
   AT_DISPATCH_ALL_TYPES(otensor.type(), "effects_buffer", [&] {
     auto* data = otensor.data<scalar_t>();
     std::copy(samples.begin(), samples.begin() + samples_read, data);
   });
+  // free buffer and close mem_read
   sox_close(input);
+  free(buffer);
+
   if (ch_first) {
     otensor.transpose_(1, 0);
   }
   sr = target_signal->rate;
 
-  // free buffer
-  free(buffer);
 #endif
   // return sample rate, output tensor modified in-place
   return sr;