Date: Tue, 30 Jul 2002 10:58:24 -0700 From: "Cliff L. Biffle" <cbiffle@safety.net> To: Jason Baker <jbaker@cs.utah.edu> Cc: multimedia@FreeBSD.ORG Subject: Re: PhotoCD: ata/acd mount issue, data overrun with lockup Message-ID: <200207301058.24713.cbiffle@safety.net> In-Reply-To: <6zheihp0rp.fsf@nephi.cs.utah.edu> References: <87d6tcgfan.fsf@thanatos.shenton.org> <6zheihp0rp.fsf@nephi.cs.utah.edu>
next in thread | previous in thread | raw e-mail | index | archive | help
On Tuesday 30 July 2002 10:46 am, Jason Baker wrote: > Ah, I had the same problem when I tried to create my own multisession > cd. What the hell does `-s <non-zero>' do exactly? Does it mount the > combined filesystem of that session and all previous ones, or just the > filesystem on that particular track. Does freebsd read multisession > discs at all? Many multi-session discs are formatted in such a way as to be backwards-compatible with audio CDs: the data track that gets used by default is the outermost track on the disc (where CD sectors and tracks are both numbered out from the hub). Audio CDs, by contrast, always start at sector 0. Thus, you can have an 'Enhanced CD', where a 'dumb' CD player plays the audio at sector 0, but a computer reads the outermost track (assuming it's data), which the audio CD player will avoid. The -s option on mount_cd9660 allows you to control this behavior. In the case of the PhotoCD above, it sounds like there's an outermost data track that's either corrupted, mismarked, or just not ISO-9660 (god forbid). Thus the default behavior (mounting the outermost track) fails. Using -s 0 attempts to mount an ISO-9660 filesystem starting at sector 0 of the disc (innermost). Likewise, using -s 1 would start on sector 1, and so forth (where CD-ROM sectors are 2048 bytes). Unless I'm mistaken, the -s x option doesn't let you mount a specific session unless you know its starting sector. However, I don't know of a good way to determine the starting sector -- is there a good FreeBSD tool for reading the TOC information? -Cliff L. Biffle To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-multimedia" in the body of the message
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?200207301058.24713.cbiffle>