text: ///////////////////////////////////////////////////////////////////////////
  //
  // Copyright (c) 2002-2012, Industrial Light & Magic, a division of Lucas
  // Digital Ltd. LLC
  // 
  // All rights reserved.
  // 
  // Redistribution and use in source and binary forms, with or without
  // modification, are permitted provided that the following conditions are
  // met:
  // *       Redistributions of source code must retain the above copyright
  // notice, this list of conditions and the following disclaimer.
  // *       Redistributions in binary form must reproduce the above
  // copyright notice, this list of conditions and the following disclaimer
  // in the documentation and/or other materials provided with the
  // distribution.
  // *       Neither the name of Industrial Light & Magic nor the names of
  // its contributors may be used to endorse or promote products derived
  // from this software without specific prior written permission. 
  // 
  // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  //
  ///////////////////////////////////////////////////////////////////////////
  
  
  
  #include <ImfHuf.h>
  #include "ImathRandom.h"
  #include <ImfArray.h>
  #include <iostream>
  #include <exception>
  #include <limits.h>
  #include <math.h>
  #include <stdlib.h>
  #include <assert.h>
  
  
  using namespace OPENEXR_IMF_NAMESPACE;
  using namespace std;
  
  
  namespace {
  
  void
  fill1 (unsigned short data[/*n*/], int n, float bias, IMATH_NAMESPACE::Rand48 & rand48)
  {
      for (int i = 0; i < n; ++i)
  	data[i] = (unsigned short)
  		  (pow (rand48.nextf(), double(bias)) * (USHRT_MAX + 1));
  }
  
  
  void
  fill2 (unsigned short data[/*n*/], int n, int m, IMATH_NAMESPACE::Rand48 & rand48)
  {
      for (int i = 0; i < n; ++i)
  	data[i] = 0;
  
      for (int i = 0; i < m; ++i)
  	data[rand48.nexti() % n] = (unsigned short) (rand48.nextf() * (USHRT_MAX + 1));
  }
  
  
  void
  fill3 (unsigned short data[/*n*/], int n, int m)
  {
      for (int i = 0; i < n; ++i)
  	data[i] = m;
  }
  
  
  void
  fill4 (unsigned short data[/*n*/], int n)
  {
      for (int i = 0; i < n; ++i)
  	data[i] = i & USHRT_MAX;
  }
  
  
  void
  fill5 (unsigned short data[/*n*/], int n)
  {
      for (int i = 0; i < n; ++i)
  	data[i] = 0;
  
      int j = 0, k = 0;
  
      for (int i = 0; i < n; ++i)
      {
  	data[i] = j;
  	j = j + k;
  	k = k + 1;
  
  	if (j > USHRT_MAX)
  	    break;
      }
  }
  
  
  void
  compressUncompress (const unsigned short raw[], int n)
  {
      Array <char> compressed (3 * n + 4 * 65536);
      Array <unsigned short> uncompressed (n);
  
      cout << "compressing " << flush;
  
      int nCompressed = hufCompress (raw, n, compressed);
  
      cout << "uncompressing " << flush;
  
      hufUncompress (compressed, nCompressed, uncompressed, n);
  
      cout << "comparing: " << flush;
  
      for (int i = 0; i < n; ++i)
  	assert (uncompressed[i] == raw[i]);
  
      cout << sizeof (raw[0]) * n << " bytes, compressed " <<
  	    nCompressed  << " bytes" << endl;
  }
  
  void
  compressUncompressSubset(const unsigned short raw[], int n)
  {
      // Test various subsets of the data set
  
      Array <char> compressed (3 * n + 4 * 65536);
      Array <unsigned short> uncompressed (n);
  
      int maxOffset = 16;
      if (n <= maxOffset) {
          maxOffset = n-1;
      }
  
      for (int offset=1; offset<maxOffset; ++offset) {
  
          int maxLength = n - offset;
          int minLength = maxLength - 16;
          if (minLength < 1) minLength = 1;
  
          for (int length=minLength; length<=maxLength; ++length) {
              cout << "compressing " << flush;
  
              int nCompressed = hufCompress (raw + offset, length, compressed + offset);
  
              cout << "uncompressing " << flush;
  
              hufUncompress (compressed + offset, nCompressed, uncompressed + offset, length);
  
              for (int i = 0; i < length; ++i)
                  assert (uncompressed[offset+i] == raw[offset+i]);
  
              cout << sizeof (raw[0]) * length << " bytes, compressed " << nCompressed  << " bytes ";
              cout << "(+" << offset << ",-" << n-offset-length << ")" << endl;
          }
      }
  }
  
  
  } // namespace
  
  
  void
  testHuf (const std::string&)
  {
      try
      {
  	cout << "Testing Huffman encoder" << endl;
  
  	IMATH_NAMESPACE::Rand48 rand48 (0);
  
  	const int N = 1000000;
  	Array <unsigned short> raw (N);
  
  	fill1 (raw, N, 1, rand48);	  // test various symbol distributions
  	compressUncompress (raw, N);
  	compressUncompressSubset (raw, N);
  	fill1 (raw, N, 10, rand48);
  	compressUncompress (raw, N);
  	compressUncompressSubset (raw, N);
  	fill1 (raw, N, 100, rand48);
  	compressUncompress (raw, N);
  	compressUncompressSubset (raw, N);
  	fill1 (raw, N, 1000, rand48);
  	compressUncompress (raw, N);
  	compressUncompressSubset (raw, N);
  
  	fill2 (raw, N, 1, rand48);
  	compressUncompress (raw, N);
  	compressUncompressSubset (raw, N);
  	fill2 (raw, N, 10, rand48);
  	compressUncompress (raw, N);
  	compressUncompressSubset (raw, N);
  	fill2 (raw, N, 100, rand48);
  	compressUncompress (raw, N);
  	compressUncompressSubset (raw, N);
  	fill2 (raw, N, 1000, rand48);
  	compressUncompress (raw, N);
  	compressUncompressSubset (raw, N);
  
  	fill3 (raw, N, 0);
  	compressUncompress (raw, N);
  	compressUncompressSubset (raw, N);
  	fill3 (raw, N, 1);
  	compressUncompress (raw, N);
  	compressUncompressSubset (raw, N);
  	fill3 (raw, N, USHRT_MAX - 1);
  	compressUncompress (raw, N);
  	compressUncompressSubset (raw, N);
  	fill3 (raw, N, USHRT_MAX);
  	compressUncompress (raw, N);
  	compressUncompressSubset (raw, N);
  
  	fill4 (raw, USHRT_MAX + 1);
  	compressUncompress (raw, USHRT_MAX + 1);
  	compressUncompressSubset (raw, USHRT_MAX + 1);
  	fill4 (raw, N);
  	compressUncompress (raw, N);
  	compressUncompressSubset (raw, N);
  
  	fill4 (raw, 0);
  	compressUncompress (raw, 0);	// test small input data sets
  	fill4 (raw, 1);
  	compressUncompress (raw, 1);
  	fill4 (raw, 2);
  	compressUncompress (raw, 2);
  	fill4 (raw, 3);
  	compressUncompress (raw, 3);
  
  	fill5 (raw, N);			// test run-length coding of code table
  	compressUncompress (raw, N);
  	compressUncompressSubset (raw, N);
  
  	cout << "ok\n" << endl;
      }
      catch (const std::exception &e)
      {
  	cerr << "ERROR -- caught exception: " << e.what() << endl;
  	assert (false);
      }
  }
  