more sanity checks and helper functions

include/libnyquist/Common.h

@@ -246,6 +246,8 @@ struct NyquistFileBuffer
 
 NyquistFileBuffer ReadFile(std::string pathToFile);
     
+int GetFormatBitsPerSample(PCMFormat f);
+
 } // end namespace nqr
 
 #endif

include/libnyquist/Dither.h

@@ -33,6 +33,12 @@ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 namespace nqr
 {
     
+enum DitherType
+{
+    DITHER_ONE,
+    DITHER_TWO
+};
+    
 } // end namespace nqr
 
 #endif

include/libnyquist/RiffUtils.h

@@ -28,6 +28,7 @@ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 #include "Common.h"
 #include "WavDecoder.h"
+#include "Dither.h"
 
 namespace nqr
 {
@@ -38,10 +39,11 @@ namespace nqr
 
 struct EncoderParams
 {
-    int channels;
-    int samplerate;
-    int bit_depth;
-    PCMFormat fmt;
+    int channelCount;
+    int sampleRate;
+    int bitDepth;
+    PCMFormat targetFormat;
+    DitherType dither;
 };
 
 struct ChunkHeaderInfo

src/Common.cpp

@@ -145,3 +145,25 @@ void nqr::ConvertToFloat32(float * dst, const int32_t * src, const size_t N, PCM
             dst[i] = int32_to_float32(Read32(src[i]));
     }
 }
+
+int nqr::GetFormatBitsPerSample(PCMFormat f)
+{
+    switch(f)
+    {
+        case PCM_U8:
+        case PCM_S8:
+            return 8;
+        case PCM_16:
+            return 16;
+        case PCM_24:
+            return 24;
+        case PCM_32:
+        case PCM_FLT:
+            return 32;
+        case PCM_64:
+        case PCM_DBL:
+            return 64;
+        default:
+            return 0;
+    }
+}

src/WavEncoder.cpp

@@ -68,11 +68,17 @@ int WavEncoder::WriteFile(const EncoderParams p, const AudioData * d, const std:
         return EncoderError::BufferTooBig;
     }
     
+    // No resampling
+    if (d->sampleRate != p.sampleRate)
+    {
+        return EncoderError::UnsupportedSamplerate;
+    }
+    
     std::ofstream fout(path.c_str(), std::ios::out | std::ios::binary);
     
     if (!fout.is_open())
     {
-        throw std::runtime_error("File cannot be opened");
+        return EncoderError::FileIOError;
     }
     
     char * chunkSizeBuff = new char[4];
@@ -94,12 +100,14 @@ int WavEncoder::WriteFile(const EncoderParams p, const AudioData * d, const std:
     fout.write(GenerateChunkCodeChar('d', 'a', 't', 'a'), 4);
     
     // + data chunk size
-    auto numSamplesBytes =  data.size() * sizeof(float);
+    auto numSamplesBytes =  d->samples.size() * sizeof(float);
     toBytes(numSamplesBytes, chunkSizeBuff);
     fout.write(chunkSizeBuff, 4);
     
     // Debugging -- assume IEEE_Float
-    fout.write(reinterpret_cast<const char*>(data.data()), numSamplesBytes);
+    
+    auto LookupB
+    fout.write(reinterpret_cast<const char*>(d->samples.data()), numSamplesBytes);
     
     // Find size
     long totalSize = fout.tellp();
@@ -113,4 +121,6 @@ int WavEncoder::WriteFile(const EncoderParams p, const AudioData * d, const std:
     fout.write(chunkSizeBuff, 4);
 
     delete[] chunkSizeBuff;
+    
+    return EncoderError::NoError;
 }