When converting the PPT attached to a PPTX and back again to a PPT the file size gets bigger. I ran a loop to do this conversion 50 times.
The original PPT was 4,533,248 bytes
The original PPT was converted to PPTX and back to PPT the first time round and its size was 6713856.
Then after 10 rounds the size grew again to 6714368.
And then after 30 rounds the size grew to 6714880.
So the new PPT file ended up being 6,714,880 bytes in size.
Using - aspose-slides-20.5-jdk16.jar
Using this code:
for (int n = 1 ; n <= count ; n = n+1 ) {
//Translate input.ppt.ppt to input.ppt.pptx
com.aspose.slides.Presentation presentation = new com.aspose.slides.Presentation(pptPath);
presentation.save(outputPath, com.aspose.slides.SaveFormat.Pptx);
System.out.println("Translated " + pptPath + " to " + outputPath);
//Translate input.ppt.pptx to input.ppt.ppt
com.aspose.slides.Presentation presentation2 = new com.aspose.slides.Presentation(outputPath);
presentation2.save(pptPath, com.aspose.slides.SaveFormat.Ppt);
File file = new File(pptPath);
System.out.println(n + ": Translated " + outputPath + " to " + pptPath + " size " + file.length());
}
The original file is attached here:
sizesGetsBigger.zip (4.3 MB)