Hi, when experimenting with IoStreams a bit, I tried bzip2 compression, too. In contrast to zlib and gzip compression, it did not work as expected. I have a bit weird behavior in two aspects. a) Unknown error code: ====================== The attached code yields: Caught bzip2 error with code: -2 data_error: -4 data_error_magic: -5 config_error: -9 So for some reason, I am catching a bzip2_error with an error code which is not even documented. When I replace gzip2 by zlib, it works fine. b) Empty output of compression: =============================== When I use a std::ofstream instead of the decompressingStream, I get an empty file. This might be the reason for a), but then I would have expected data_error or data_error_magic? Decompressing the content of a valid bzip2 compressed file works fine. Any ideas what might be going wrong? Thanks in advance, Roland