* cleaned up (and fixed) code for generating duration

src/main.cpp

@@ -60,29 +60,26 @@ int main(int argc, char* argv[])
     ofs << "  \"_generator\":\"wav2json version " << version::version << " on " << version::platform << " (http://goo.gl/af7wg)\"," << std::endl;
   }
 
-  for(size_t i = 0; i != options.channels.size(); ++i)
+  // open sound file
+  SndfileHandle wav(options.input_file_name.c_str());
+
+  // Handle error
+  if ( wav.error() )
   {
-    // open sound file
-    SndfileHandle wav(options.input_file_name.c_str());
+      cerr << "Error opening audio file '" << options.input_file_name << "'" << endl;
+      cerr << "Error was: '" << wav.strError() << "'" << endl; 
+      return 2;
+  }
 
-	// // output sound duration
-	// if (i == 0) {
-	// 	ofs << "  \"duration\":" << wav.frames()/(float)wav.samplerate() << "," << std::endl;	  
-	// }
-
-    // Handle error
-    if ( wav.error() )
-    {
-        cerr << "Error opening audio file '" << options.input_file_name << "'" << endl;
-        cerr << "Error was: '" << wav.strError() << "'" << endl; 
-        return 2;
-    }
+  for(size_t i = 0; i != options.channels.size(); ++i)
+  {
+    wav.seek(0, SEEK_SET);
 
     Options::Channel channel = options.channels[i];
 
     ofs << "  \"" << channel << "\":";
 
-    float sampleDur = compute_waveform(
+    compute_waveform(
       wav,
       ofs,
       options.samples,
@@ -93,16 +90,14 @@ int main(int argc, char* argv[])
       progress_callback
     );
 
-    // if (i != options.channels.size()-1) //only write comma, if this is not the last entry
-    //   ofs << "," << std::endl;
-
-	ofs << "," << std::endl;
-	if (i == options.channels.size()-1) {
-		ofs << std::endl;
-		ofs << "  \"duration\":" << sampleDur;
-	}
+	  ofs << "," << std::endl;
   }
 
+  // increase precission for duration
+  ofs << std::fixed; //explicitly use fixed notation
+  ofs.precision( std::numeric_limits<float>::digits10 );
+
+  ofs << "  \"duration\":" << wav.frames() / float(wav.samplerate());
   ofs << std::endl << "}" << std::endl;
 
   cerr << endl;

src/wav2json.cpp

@@ -80,7 +80,7 @@ T compute_sample(const std::vector<T>& block, int i, int n_channels, Options::Ch
 /*
   compute the waveform of the supplied audio-file and store it into out_image.
 */
-float compute_waveform(
+void compute_waveform(
   const SndfileHandle& wav,
   std::ostream& output_stream,
   size_t samples,
@@ -135,12 +135,8 @@ float compute_waveform(
   for (size_t x = 0; x < samples; ++x)
   {
 	  // read frames
-	  //int pos = (int)(x*wav.frames()/samples);
-	  //const_cast<SndfileHandle&>(wav).seek(pos, SEEK_SET);
     sf_count_t n = const_cast<SndfileHandle&>(wav).readf(&block[0], frames_per_pixel) * wav.channels();
     assert(n <= (sf_count_t)block.size());
-	// std::cout << "frames: " << const_cast<SndfileHandle&>(wav).seek(0, SEEK_CUR) << std::endl;
-
 
     // find min and max
     sample_type max(0);
@@ -163,20 +159,13 @@ float compute_waveform(
     if ( x%(progress_divisor) == 0 )
     {
       if ( progress_callback && !progress_callback( 100*x/samples ) )
-          return 0;
+          return;
     }
   }
 
   // call the progress callback
   if ( progress_callback && !progress_callback( 100 ) )
-    return 0;
+    return;
 
   output_stream << "]";
-  std::cout << "frames: " << const_cast<SndfileHandle&>(wav).seek(0, SEEK_CUR) << std::endl;
-  std::cout << "frames2: " << frames_per_pixel*samples << std::endl;
-  std::cout << "sample duration: " << const_cast<SndfileHandle&>(wav).seek(0, SEEK_CUR)/wav.samplerate() << std::endl;
-  std::cout << "sample duration2: " << (frames_per_pixel*samples)/(float)wav.samplerate() << std::endl;
-  std::cout << "total frames " << wav.frames() << std::endl;
-  std::cout << "total duration: " <<  wav.frames()/(float)wav.samplerate()<< std::endl;
-  return (frames_per_pixel*samples)/(float)wav.samplerate();
 }

src/wav2json.hpp

@@ -7,7 +7,7 @@
     typedef bool (*progress_callback_t)(size_t progress);
 #endif /* __OBJC__ */
 
-float compute_waveform(
+void compute_waveform(
   const SndfileHandle& wav,
   std::ostream& output_stream,
   size_t samples,