Allow webrtc compilation with stlport

modules/audio_processing/intelligibility/intelligibility_utils.cc

 /*
  *  Copyright (c) 2014 The WebRTC project authors. All Rights Reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
@@ skipping 14 matching lines @@
 
 namespace intelligibility {
 
 float UpdateFactor(float target, float current, float limit) {
   float delta = fabsf(target - current);
   float sign = copysign(1.0f, target - current);
   return current + sign * fminf(delta, limit);
 }
 
 bool cplxfinite(complex<float> c) {
   return std::isfinite(c.real()) && std::isfinite(c.imag());

[Andrew MacDonald, 2015/07/22 19:41:30]

This is also C++11 standard library...

[jdduke (slow), 2015/07/22 19:51:00]

Ah, the joys and quirks of stlport. They seem to have haphazardly included a
number of C++11 library features which makes gleaning out the  real offenses a
bit trickier.

 }
 
 bool cplxnormal(complex<float> c) {
-  return std::isnormal(c.real()) && std::isnormal(c.imag());
+  return isnormal(c.real()) && isnormal(c.imag());

[Andrew MacDonald, 2015/07/22 19:41:30]

Actually this is failing for me on Linux ("use of undeclared identifier
'isnormal'"). We could add a wrapper with hacky platform #ifdefs, but I think
better to remove this entirely because it shouldn't really be needed.

Filed a bug here:
https://code.google.com/p/webrtc/issues/detail?id=4866

Could you revert the change to this file? I can at least land the data() fix.

[jdduke (slow), 2015/07/22 19:51:00]

Done.

 }
 
 complex<float> zerofudge(complex<float> c) {
   const static complex<float> fudge[7] = {{0.001f, 0.002f},
                                           {0.008f, 0.001f},
                                           {0.003f, 0.008f},
                                           {0.0006f, 0.0009f},
                                           {0.001f, 0.004f},
                                           {0.003f, 0.004f},
                                           {0.002f, 0.009f}};
   static int fudge_index = 0;
   if (cplxfinite(c) && !cplxnormal(c)) {

[ekm, 2015/07/22 21:26:37]

The C++11 stuff is overkill. I think we can just change this to 

if (c.real() == 0.f || c.imag() == 0.f) {

and get completely get rid of both definitions of cplxnormal and cplxfinite
above. This still passes all tests, and we haven't documented any subnormal
behavior here yet so we should be ok. You'd can also get rid of the EXPECTs that
call those functions in intelligibility_utils_unittest.cc, which is the only
other place these are called.

     fudge_index = (fudge_index + 1) % 7;
     return c + fudge[fudge_index];
   }
   return c;
 }
 
 complex<float> NewMean(complex<float> mean, complex<float> data, int count) {
   return mean + (data - mean) / static_cast<float>(count);
 }
 
@@ skipping 252 matching lines @@
   for (int i = 0; i < freqs; ++i) {
     target_[i] = 1.0f;
     current_[i] = 1.0f;
   }
 }
 
 void GainApplier::Apply(const complex<float>* in_block,
                         complex<float>* out_block) {
   for (int i = 0; i < freqs_; ++i) {
     float factor = sqrtf(fabsf(current_[i]));
-    if (!std::isnormal(factor)) {
+    if (!isnormal(factor)) {
       factor = 1.0f;
     }
     out_block[i] = factor * in_block[i];
     current_[i] = UpdateFactor(target_[i], current_[i], change_limit_);
   }
 }
 
 }  // namespace intelligibility
 
 }  // namespace webrtc