Use a consistent default buffer size throughout

Author: flanglet

src/io/CompressedOutputStream.cpp

@@ -124,7 +124,7 @@ CompressedOutputStream::CompressedOutputStream(OutputStream& os,
     _ctx.putInt("bsVersion", BITSTREAM_FORMAT_VERSION);
 
     // Allocate first buffer and add padding for incompressible blocks
-    const int bufSize = max(_blockSize + (_blockSize >> 6), 65536);
+    const int bufSize = max(_blockSize + (_blockSize >> 3),  512 * 1024);
     _buffers[0] = new SliceArray<byte>(new byte[bufSize], bufSize, 0);
     _buffers[_jobs] = new SliceArray<byte>(new byte[0], 0, 0);
 
@@ -208,7 +208,7 @@ CompressedOutputStream::CompressedOutputStream(OutputStream& os, Context& ctx, b
     _buffers = new SliceArray<byte>*[2 * _jobs];
 
     // Allocate first buffer and add padding for incompressible blocks
-    const int bufSize = max(_blockSize + (_blockSize >> 6), 65536);
+    const int bufSize = max(_blockSize + (_blockSize >> 3),  512 * 1024);
     _buffers[0] = new SliceArray<byte>(new byte[bufSize], bufSize, 0);
     _buffers[_jobs] = new SliceArray<byte>(new byte[0], 0, 0);
 
@@ -356,7 +356,7 @@ ostream& CompressedOutputStream::write(const char* data, streamsize length)
 
                 if (_bufferId + 1 < nbTasks) {
                     _bufferId++;
-                    const int bufSize = max(_blockSize + (_blockSize >> 6), 65536);
+                    const int bufSize = max(_blockSize + (_blockSize >> 3), 512 * 1024);
 
                     if (_buffers[_bufferId]->_length == 0) {
                         delete[] _buffers[_bufferId]->_array;