Fix broken writing of 16-bit images (the pixels must be written MSB-first).

diff --git a/test/test.cc b/test/test.cc
index a761eb520c2b79352b21c836809c4d61c088d633..9261ce43ba0e0515fa4e57dd3e29fc5ce28eb7f3 100644 (file)
--- a/test/test.cc
+++ b/test/test.cc
@@ -741,9 +741,40 @@ write_image (shared_ptr<const Image> image, boost::filesystem::path file)
 
        png_set_IHDR (png_ptr, info_ptr, image->size().width, image->size().height, bits_per_pixel, png_color_type, PNG_INTERLACE_NONE, PNG_COMPRESSION_TYPE_DEFAULT, PNG_FILTER_TYPE_DEFAULT);
 
-       png_byte ** row_pointers = reinterpret_cast<png_byte **>(png_malloc(png_ptr, image->size().height * sizeof(png_byte *)));
-       for (int i = 0; i < image->size().height; ++i) {
-               row_pointers[i] = (png_byte *) (image->data()[0] + i * image->stride()[0]);
+       auto const width = image->size().width;
+       auto const height = image->size().height;
+       auto const stride = image->stride()[0];
+
+       vector<vector<uint8_t>> data_to_write(height);
+       for (int y = 0; y < height; ++y) {
+               data_to_write[y].resize(stride);
+       }
+
+       switch (image->pixel_format()) {
+       case AV_PIX_FMT_RGB24:
+               for (int y = 0; y < height; ++y) {
+                       memcpy(data_to_write[y].data(), image->data()[0] + y * stride, stride);
+               }
+               break;
+       case AV_PIX_FMT_XYZ12LE:
+               /* 16-bit pixel values must be written MSB first */
+               for (int y = 0; y < height; ++y) {
+                       data_to_write[y].resize(stride);
+                       uint8_t* original = image->data()[0] + y * stride;
+                       for (int x = 0; x < width * 3; ++x) {
+                               data_to_write[y][x * 2] = original[1];
+                               data_to_write[y][x * 2 + 1] = original[0];
+                               original += 2;
+                       }
+               }
+               break;
+       default:
+               break;
+       }
+
+       png_byte ** row_pointers = reinterpret_cast<png_byte**>(png_malloc(png_ptr, image->size().height * sizeof(png_byte *)));
+       for (int y = 0; y < height; ++y) {
+               row_pointers[y] = reinterpret_cast<png_byte*>(data_to_write[y].data());
        }
 
        png_write_info (png_ptr, info_ptr);