From erikjensen at rkjnsn.net Wed Sep 9 04:43:45 2026 From: erikjensen at rkjnsn.net (Erik Jensen) Date: Tue, 8 Sep 2026 21:43:45 -0700 Subject: [libdvdcss-devel] Cache CPPM album ID / media key / k_au? In-Reply-To: References: Message-ID: For my personal media preservation, I currently backup an encrypted disc image bit-for-bit, and then store alongside it whatever is stored separately from that on the disc that is needed to play it. That's the volume ID for a Blu-ray, the title keys for DVD-Video, and would be the album ID for DVD-Audio. For playback, those bits can be copied into the appropriate library's cache directory. That's ~/.cache/aacs/vid for Blu-ray, and ~/.dvdcss for DVD-Video. However, there doesn't appear to be anything similar for DVD-Audio. As far as I can tell, the new CPPM support unconditionally attempts to retrieve the album ID via an ioctl and provides no support for reading a disc image. Would support for such a cache be accepted? If so, what should the shape be? Same disc ID as the CSS cache uses, or something DVD-Audio specific? Only support caching the album ID, or the media key and k_au, too (mirroring libaacs)? Thanks!