base: Introducing utility for writing raw data in png format

Originally it was possible to use a Bitmap writer class for dumping a
framebuffer snapshot in a .bmp file. This patch enables you to choose
another format.  In particular it implements the writing of PNG Images
using libpng library.  The latter has to be already installed in your
machine, otherwise gem5 will default to the Bitmap format.  This
configurable writer has been introduced in the VNC frame dumping mechanism,
which is storing changed frame buffers from the VNC server

Change-Id: Id7e5763c82235f1ce90381c8486b85a7cce734ce
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/5181
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>

1 files changed, 113 insertions, 0 deletions

diff --git a/src/base/bmpwriter.cc b/src/base/bmpwriter.cc
new file mode 100644
index 000000000..f650074ab
--- /dev/null
+++ b/src/base/bmpwriter.cc
@@ -0,0 +1,113 @@
+/*
+ * Copyright (c) 2010, 2015, 2017 ARM Limited
+ * All rights reserved
+ *
+ * The license below extends only to copyright in the software and shall
+ * not be construed as granting a license to any other intellectual
+ * property including but not limited to intellectual property relating
+ * to a hardware implementation of the functionality of the software
+ * licensed hereunder.  You may use the software subject to the license
+ * terms below provided that you ensure that this notice is replicated
+ * unmodified and in its entirety in all distributions of the software,
+ * modified or unmodified, in source code or in binary form.
+ *
+ * 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 the copyright holders 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.
+ *
+ * Authors: William Wang
+ *          Ali Saidi
+ *          Chris Emmons
+ *          Andreas Sandberg
+ */
+
+#include "base/bmpwriter.hh"
+
+#include <cassert>
+
+#include "base/misc.hh"
+
+const char* BmpWriter::_imgExtension = "bmp";
+
+// bitmap class ctor
+BmpWriter::BmpWriter(const FrameBuffer *_fb)
+    : ImgWriter(_fb)
+{
+}
+
+const BmpWriter::CompleteV1Header
+BmpWriter::getCompleteHeader() const
+{
+    const uint32_t pixel_array_size(sizeof(PixelType) * fb.area());
+    const uint32_t file_size(sizeof(CompleteV1Header) + pixel_array_size);
+
+    const CompleteV1Header header = {
+        // File header
+        {
+            {'B','M'}, /* Magic */
+            file_size,
+            0, 0, /* Reserved */
+            sizeof(CompleteV1Header) /* Offset to pixel array */
+        },
+        // Info/DIB header
+        {
+            sizeof(InfoHeaderV1),
+            fb.width(),
+            fb.height(),
+            1, /* Color planes */
+            32, /* Bits per pixel */
+            0, /* No compression */
+            pixel_array_size, /* Image size in bytes */
+            2835, /* x pixels per meter (assume 72 DPI) */
+            2835, /* y pixels per meter (assume 72 DPI) */
+            0, /* Colors in color table */
+            0 /* Important color count (0 == all are important) */
+        }
+    };
+
+    return header;
+}
+
+void
+BmpWriter::write(std::ostream &bmp) const
+{
+    const CompleteV1Header header(getCompleteHeader());
+
+    // 1.  write the header
+    bmp.write(reinterpret_cast<const char *>(&header), sizeof(header));
+
+    // 2.  write the bitmap data
+    // BMP start store data left to right starting with the bottom row
+    // so we need to do some creative flipping
+    std::vector<PixelType> line_buffer(fb.width());
+    for (int y = 0; y < fb.height(); ++y) {
+        for (unsigned x = 0; x < fb.width(); ++x)
+            line_buffer[x] = fb.pixel(x, fb.height() - y - 1);
+
+        bmp.write(reinterpret_cast<const char *>(line_buffer.data()),
+                  line_buffer.size() * sizeof(line_buffer[0]));
+    }
+
+    bmp.flush();
+}
+
+