implement tri dithering... API needs a little work to be extensible

examples/src/Main.cpp

@@ -92,7 +92,7 @@ int main()
 	}
     
     // Test wav file encoder
-    int encoderStatus = encoder.WriteFile({1, PCM_24, DITHER_NONE}, fileData, "encoded.wav");
+    int encoderStatus = encoder.WriteFile({1, PCM_16, DITHER_NONE}, fileData, "encoded.wav");
     std::cout << "Encoder Status: " << encoderStatus << std::endl;
     
 	return 0;

include/libnyquist/Common.h

@@ -215,11 +215,11 @@ static const float NQR_BYTE_2_FLT = 1.0f / 127.0f;
 #define int24_to_float32(s) ((float) (s) / NQR_INT24_MAX)
 #define int32_to_float32(s) ((float) (s) / NQR_INT32_MAX)
     
-#define float32_to_int8(s)  (int8_t)  (s * 127.f)
-#define float32_to_uint8(s) (uint8_t)((s * 127.f) + 128)
-#define float32_to_int16(s) (int16_t) (s * NQR_INT16_MAX)
-#define float32_to_int24(s) (int32_t) (s * NQR_INT24_MAX)
-#define float32_to_int32(s) (int32_t) (s * NQR_INT32_MAX)
+#define float32_to_int8(s)  (float) (s * 127.f)
+#define float32_to_uint8(s) (float) ((s * 127.f) + 128)
+#define float32_to_int16(s) (float) (s * NQR_INT16_MAX)
+#define float32_to_int24(s) (float) (s * NQR_INT24_MAX)
+#define float32_to_int32(s) (float) (s * NQR_INT32_MAX)
 
 //@todo add 12, 20 for flac
 enum PCMFormat

src/Common.cpp

@@ -152,23 +152,25 @@ void nqr::ConvertFromFloat32(uint8_t * dst, const float * src, const size_t N, P
     
     assert(f != PCM_END);
     
+    TriDither dither;
+    
     if (f == PCM_U8)
     {
         uint8_t * destPtr = reinterpret_cast<uint8_t *>(dst);
         for (size_t i = 0; i < N; ++i)
-            destPtr[i] = float32_to_uint8(src[i]);
+            destPtr[i] = (t == DITHER_TRIANGLE) ? (uint8_t) lroundf(dither(float32_to_uint8(src[i]))) : (uint8_t) float32_to_uint8(src[i]);
     }
     else if (f == PCM_S8)
     {
         int8_t * destPtr = reinterpret_cast<int8_t *>(dst);
         for (size_t i = 0; i < N; ++i)
-            destPtr[i] = float32_to_int8(src[i]);
+            destPtr[i] = (t == DITHER_TRIANGLE) ? (int8_t) lroundf(dither(float32_to_int8(src[i]))) : (int8_t) float32_to_int8(src[i]);
     }
     else if (f == PCM_16)
     {
         int16_t * destPtr = reinterpret_cast<int16_t *>(dst);
         for (size_t i = 0; i < N; ++i)
-            destPtr[i] = float32_to_int16(src[i]);
+            destPtr[i] = (t == DITHER_TRIANGLE) ? (int16_t) lroundf(dither(float32_to_int16(src[i]))) : (int16_t) float32_to_int16(src[i]);
     }
     else if (f == PCM_24)
     {
@@ -176,7 +178,7 @@ void nqr::ConvertFromFloat32(uint8_t * dst, const float * src, const size_t N, P
         size_t c = 0;
         for (size_t i = 0; i < N; ++i)
         {
-            auto sample = float32_to_int24(src[i]);
+            int32_t sample = (t == DITHER_TRIANGLE) ? (int32_t) lroundf(dither(float32_to_int24(src[i]))) : (int32_t) float32_to_int24(src[i]);
             auto unpacked = Unpack(sample); // Handles endian swap
             destPtr[c] = unpacked[0];
             destPtr[c+1] = unpacked[1];
@@ -188,7 +190,7 @@ void nqr::ConvertFromFloat32(uint8_t * dst, const float * src, const size_t N, P
     {
         int32_t * destPtr = reinterpret_cast<int32_t *>(dst);
         for (size_t i = 0; i < N; ++i)
-            destPtr[i] = float32_to_int32(src[i]);
+            destPtr[i] = (t == DITHER_TRIANGLE) ? (int32_t) lroundf(dither(float32_to_int32(src[i]))) : (int32_t) float32_to_int32(src[i]);
     }
 }
 

src/WavEncoder.cpp

@@ -127,7 +127,6 @@ int WavEncoder::WriteFile(const EncoderParams p, const AudioData * d, const std:
         fout.write(reinterpret_cast<const char*>(d->samples.data()), samplesSizeInBytes);
     }
     
-
     // Padding byte
     if (isOdd(samplesSizeInBytes))
     {