Locate and position the current Audacity source code, and clear a variety of old junk out of the way into junk-branches

src/SampleFormat.cpp

@@ -0,0 +1,124 @@
+/**********************************************************************
+
+  Audacity: A Digital Audio Editor
+
+  SampleFormat.h
+
+  Dominic Mazzoni
+
+*******************************************************************//*!
+
+\file SampleFormat.cpp
+\brief Functions that work with Dither and initialise it.
+
+
+  This file handles converting between all of the different
+  sample formats that Audacity supports, such as 16-bit,
+  24-bit (packed into a 32-bit int), and 32-bit float.
+
+  Floating-point samples use the range -1.0...1.0, inclusive.
+  Integer formats use the full signed range of their data type,
+  for example 16-bit samples use the range -32768...32767.
+  This means that reading in a wav file and writing it out again
+  ('round tripping'), via floats, is lossless; -32768 equates to -1.0f 
+  and 32767 equates to +1.0f - (a little bit).
+  It also means (unfortunatly) that writing out +1.0f leads to
+  clipping by 1 LSB.  This creates some distortion, but I (MJS) have
+  not been able to measure it, it's so small.  Zero is preserved.
+
+  http://limpet.net/audacity/bugzilla/show_bug.cgi?id=200
+  leads to some of the discussions that were held about this.
+
+   Note: These things are now handled by the Dither class, which
+         also replaces the CopySamples() method (msmeyer)
+
+*//*******************************************************************/
+
+#include <wx/intl.h>
+#include <math.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "SampleFormat.h"
+#include "Prefs.h"
+#include "Dither.h"
+
+Dither::DitherType gLowQualityDither = Dither::none;
+Dither::DitherType gHighQualityDither = Dither::none;
+Dither gDitherAlgorithm;
+
+void InitDitherers()
+{
+   // Read dither preferences
+   gLowQualityDither = (Dither::DitherType)
+   gPrefs->Read(wxT("/Quality/DitherAlgorithm"), (long)Dither::none);
+
+   gHighQualityDither = (Dither::DitherType)
+   gPrefs->Read(wxT("/Quality/HQDitherAlgorithm"), (long)Dither::shaped);
+}
+
+const wxChar *GetSampleFormatStr(sampleFormat format)
+{
+   switch(format) {
+   case int16Sample:
+      /* i18n-hint: Audio data bit depth (precision): 16-bit integers */
+      return _("16-bit PCM");
+   case int24Sample:
+      /* i18n-hint: Audio data bit depth (precision): 24-bit integers */
+      return _("24-bit PCM");
+   case floatSample:
+      /* i18n-hint: Audio data bit depth (precision): 32-bit floating point */
+      return _("32-bit float");
+   }
+   return wxT("Unknown format"); // compiler food
+}
+
+AUDACITY_DLL_API samplePtr NewSamples(int count, sampleFormat format)
+{
+   return (samplePtr)malloc(count * SAMPLE_SIZE(format));
+}
+
+AUDACITY_DLL_API void DeleteSamples(samplePtr p)
+{
+   free(p);
+}
+
+void ClearSamples(samplePtr src, sampleFormat format,
+                  int start, int len)
+{
+   int size = SAMPLE_SIZE(format);
+   memset(src + start*size, 0, len*size);
+}
+
+void CopySamples(samplePtr src, sampleFormat srcFormat,
+                 samplePtr dst, sampleFormat dstFormat,
+                 unsigned int len,
+                 bool highQuality, /* = true */
+                 unsigned int stride /* = 1 */)
+{
+   gDitherAlgorithm.Apply(
+      highQuality ? gHighQualityDither : gLowQualityDither,
+      src, srcFormat, dst, dstFormat, len, stride);
+}
+
+void CopySamplesNoDither(samplePtr src, sampleFormat srcFormat,
+                 samplePtr dst, sampleFormat dstFormat,
+                 unsigned int len,
+                 unsigned int stride /* = 1 */)
+{
+   gDitherAlgorithm.Apply(
+      Dither::none,
+      src, srcFormat, dst, dstFormat, len, stride);
+}
+
+// Indentation settings for Vim and Emacs and unique identifier for Arch, a
+// version control system. Please do not modify past this point.
+//
+// Local Variables:
+// c-basic-offset: 3
+// indent-tabs-mode: nil
+// End:
+//
+// vim: et sts=3 sw=3
+// arch-tag: 1dacb18a-a027-463b-b558-73b6d24995d6