Re: How To Read Volume ID from DVD
Hi, The explanation for why volname returned CDROM is that is apparently the default volume label when none is specified (which wasn't in the first session). I specified volly on a later session but volname and vol_id (which someone else suggested) appear to not be multi-session aware and return data only from the first session. This effect dependends on the media type. It appears with sequential media like CD, DVD-R[W], DVD+R, BD-R, but not with overwriteable ones like DVD+RW, DVD-RAM, DVD-RW formatted, BD-RE. With sequential media you have to determine the start position of the most recent session and to look there for the Primary Volume Descriptor which holds the volume id. With overwriteable media it was the job of the burn program to install a PVD copy at the start of the media. So with overwriteables, there is no need to find the real start of the last session. The fact that the volume identifier tools do not know the mount rules for sequential multi- session media appears to be a birth defect: To learn about the media type and eventually the start of the most recent session they would need to identify the media type. For that they need ioctl(). Either from the CDROM_* family, if there is a matching ioctl(), or via SG_IO with commands from the MMC standard. Both seems not to be in their scope. [xorriso] I see its -toc mode emits the volume IDs for each session, vs.wodim -toc which doesn't show this. xorriso is an integrated ISO 9660 multi-session tool. wodim (resp. cdrecord) is a burn tool which is not entitled to know about ISO 9660 entrails. I had begun reading ECMA-119 last night when it appeared there was no way to do this but write my own code. There can never be enough experts. My case is multi-session discs so it'll take a little more than this. I've still got to look at ECMA-168 xorriso does not rely on ECMA-168 but on ECMA-119 plus some SUSP based extensions like Rock Ridge. Afaik the mkisofs runs of growisofs do not refer to ECMA-168 either. Although multi-session is not mentioned in ECMA-119, we simply fool that standard by help of the mount conventions of the operating systems. I.e. we do not violate those specs but we do things which are not explicitely mentioned there. It works fine (unless with tools like volname). I found there are various other fields (e.g. application identifier) the image creation tools will allow you to specify yet even the relatively heavy weight tools don't appear to expose, so I'm going to write a simple tool a la volname but multi-session aware and that can report the other volume descriptor fields. How about we integrate this into xorriso as a command option ? The task to find the PVD is not trivial and xorriso already can do that. What info would you like to extract ? Have a nice day :) Thomas -- To UNSUBSCRIBE, email to cdwrite-requ...@other.debian.org with a subject of unsubscribe. Trouble? Contact listmas...@other.debian.org
Re: How To Read Volume ID from DVD
xorriso does not rely on ECMA-168 but on ECMA-119 plus some SUSP based extensions like Rock Ridge. Afaik the mkisofs runs of growisofs do not refer to ECMA-168 either. Yes, today I perused ECMA-168 and realized it specifies a form of layout different than what my burnt discs conform to (i.e. it uses a descriptor identifier of CDW02, vs. growisofs's CD001 which is ECMA-119). Although multi-session is not mentioned in ECMA-119, we simply fool that standard by help of the mount conventions of the operating systems. I.e. we do not violate those specs but we do things which are not explicitely mentioned there. It works fine (unless with tools like volname). Indeed I have been frustrated trying to find out a description of multi-session ECMA-119 layout. Is this written up somewhere or nothing more than having to reverse engineer some de facto standard implementation (yuck)? (To wit, the Volume Space Size field from the Primary Volume Descriptor from ECMA-119 doesn't fully account for the difference between sessions.) How about we integrate this into xorriso as a command option ? The task to find the PVD is not trivial and xorriso already can do that. What info would you like to extract ? Well, if you'd be up for it that'd be appreciated. All the textual fields from the ECMA-119 volume descriptor can be specified in growisofs (to name one), as well they should but reading them back is lacking: system identifier, volume identifier, volume set identifier, publisher identifier, data preparer identifier, application identifier, copyright file identifier, abstract file identifier, bibliographic file identifier. -- To UNSUBSCRIBE, email to cdwrite-requ...@other.debian.org with a subject of unsubscribe. Trouble? Contact listmas...@other.debian.org
Re: How To Read Volume ID from DVD
Hi, growisofs's CD001 That's actually mkisofs's CD001. growisofs -M examines media TOC resp. the ECMA-119 PVD in order to get the parameters for a run of mkisofs -C . growisofs then starts mkisofs and writes its output to the media. In case of overwriteable media it finally copies the Volume Descriptors of the new session to the start of the media. xorriso does about the same but uses libraries libisofs, libburn and libisoburn. On overwriteable media it puts the first session to LBA 32 rather than 0. This protects the PVD of the first session from being overwritten by the PVD copies of further sessions. So it is possible to follow a chain of sessions when printing a table-of-content. Indeed I have been frustrated trying to find out a description of multi-session ECMA-119 layout. The idea is quite simple: Mount uses as superblock address the start of the first track in the last session. At this address it expects a System Area of 16 blocks followed by a Volume Descriptor Set. It is interested in the PVD which tells the address of the Directory Entry of the root directory and the size of the image. The only deviation from ECMA-119 is that the superblock address is not 0. Prescribed is: 6.2.1 System Area and Data Area The System Area shall occupy the Logical Sectors with Logical Sector Numbers 0 to 15. [...] 6.7.1 Volume Descriptor Set A Volume Descriptor Set shall be a sequence of volume descriptors recorded in consecutively numbered Logical Sectors starting with the Logical Sector Number 16. Everything else in our doings follows ECMA-119 resp. squeezes itself into the niches which have been left open in that standard. E.g. SUSP, Rock Ridge, AAIP use a few reserve bytes of each directory entry to attach extra info and make ISO 9660 a decent filesystem. On sequential media we formally fulfill the demands of ECMA-119 by having an outdated system area and Volume Descriptor Set at addresses 0 and 16. On overwriteable media we fulfill ECMA-119 completely by putting an updated copy of the prescribed stuff to LBA 0 to 16. The El-Torito specs for booting support our interpretation of ECMA-119 liberty by prescribing to use the System Area of the last session. Nevertheless many BIOSes stick to ECMA-119 and insist in using the System Area at LBA 0 and the El-Torito boot record at LBA 17 to 31. So bootable multi-session CDs and DVDs should in each session point to the same boot objects in the image which should all sit in the first session. (To wit, the Volume Space Size field from the Primary Volume Descriptor from ECMA-119 doesn't fully account for the difference between sessions.) Oh it does. But each PVD can only give the end address of its own session. So you will see an increasing volume size in each session. It is always counted from LBA 0 and not from the start LBA of the session. I.e. a PVD covers its own session and all older sessions. system identifier, volume identifier, volume set identifier, publisher identifier, data preparer identifier, application identifier, copyright file identifier, abstract file identifier, bibliographic file identifier. How about this: $ xorriso -indev /dev/... -pvd_info ... System Id: ... Volume Id: ... Volume Set Id: ... Publisher: ... Preparer : ... Application : ... Copyright Id : ... Abstract Id : ... Bibliogr. Id : ... Have a nice day :) Thomas -- To UNSUBSCRIBE, email to cdwrite-requ...@other.debian.org with a subject of unsubscribe. Trouble? Contact listmas...@other.debian.org
Re: How To Read Volume ID from DVD
Hi, libisofs does already provide all PVD components which you requested. So it was easy to implement a sketch of -pvd_info. See some examples from my test runs. Comments and change wishes are appreciated. - Drive current: -indev '/dev/sr1' PVD address : 16s System Id: LINUX Volume Id: Debian 4.0 r0 M-A 1 Volume Set Id: Publisher Id : Preparer Id : App Id : MKISOFS ISO 9660/HFS FILESYSTEM BUILDER CDRECORD CD-R/DVD CREATOR (C) 1993 E.YOUNGDALE (C) 1997 J.PEARSON/J.SCHILLING Copyright Id : Abstract Id : Biblio Id: - Drive current: -indev '/dev/sr1' PVD address : 16s System Id: LINUX Volume Id: Ubuntu 7.10 Server Volume Set Id: Publisher Id : Preparer Id : App Id : MKISOFS ISO 9660/HFS FILESYSTEM BUILDER CDRECORD CD-R/DVD CREATOR (C) 1993 E.YOUNGDALE (C) 1997 J.PEARSON/J.SCHILLING Copyright Id : Abstract Id : Biblio Id: - Drive current: -indev '/dev/sr1' PVD address : 6924016s System Id: Volume Id: UPDATE_HOME_2009_10_04_122807 Volume Set Id: ISOIMAGE Publisher Id : Preparer Id : XORRISO-0.4.3 2009.09.30.092640, LIBISOBURN-0.4.3, LIBISOFS-0.6.2 3, LIBBURN-0.7.1 App Id : Copyright Id : _ Abstract Id : _ Biblio Id: _ - (I will have to beautify my own PVD ornaments. -volid, -publisher and -application_id are user adjustable already. I'll have to study which of the others are for the user and which are for the program.) Note the subtle differences between -toc line Volume id: '...' and -pvd_info line Volume Id: ... Would you prefer quoted output in -pvd_info ? Have a nice day :) Thomas -- To UNSUBSCRIBE, email to cdwrite-requ...@other.debian.org with a subject of unsubscribe. Trouble? Contact listmas...@other.debian.org
Re: How To Read Volume ID from DVD
These look good. Note the subtle differences between -toc line Volume id: '...' and -pvd_info line Volume Id: ... Would you prefer quoted output in -pvd_info ? For the sake of programmatic use, the known delimiters of colon-space and newline (or whatever) serves as implicit quoting for grepping. Also it seems to me the norm on such things (/proc files, etc.) is to list fields without quoting, so aesthetically I'd go with how you have it now. Much thanks. I think it's been too long there's been no (apparent, convenient) way to access these fields. -- To UNSUBSCRIBE, email to cdwrite-requ...@other.debian.org with a subject of unsubscribe. Trouble? Contact listmas...@other.debian.org
Re: How To Read Volume ID from DVD
Hi, i uploaded http://scdbackup.webframe.org/xorriso-0.4.3.tar.gz which performs the new option -pvd_info. xorriso -version should report Version timestamp 2009.10.05.190215 or newer. Try xorriso -indev ...device... -pvd_info 2/dev/null - how is the sector offset for the next session derived. As an example, a multisession disc I have has this layout: TOC layout : Idx , sbsector , Size , Volume Id ISO session : 1 , 0 , 10568s , CDROM ISO session : 2 , 12624 ,304274s , CDROM The 10568 is the volume space size field from the PVD, logically. What I don't see is how does it derive 12624 as the start of the next session, what accounts for the other 2056 sectors? Let me guess: this is a DVD+R media. The gap is 4 MB plus alignment to the next full 16 block address. Again, we have two families of media types: Sequential media have a table-of-content on the level of media and drive. See MMC-5 http://www.t10.org/ftp/t10/drafts/mmc5/mmc5r03c.pdf commands 51h READ DISC INFORMATION and 52h READ TRACK INFORMATION or 43h READ TOC/PMA/ATIP. The mount command learns from this info where the last session begins. It does not have to interpret the payload data content for that. The drive decides where the next track may begin: TRACK INFORMATION field Next Writeable Address. In case of DVD+R this is about 4 MB after the last track end. DVD-R and CD have even larger gaps. Overwriteable media have no real table-of-content. The drive reports stubbornly a single session with a single track. So in this case the mount command must get its superblock at address 0. After each new session the first 16+ blocks of the media have to be updated by a copy of the first 16+ blocks of the new session. For printing an emulated table-of-content it is necessary to interpret the PVDs of the sessions. The first one can be found at LBA 32+16 and tells the size of its session. The next one can be found shortly after the session end. In case of xorriso this is the next address divisible by 32. growisofs aligns rather to 16 and spoils the chain of sessions by placing the first one at LBA 0 which gets overwritten with each new session. The Next Writeable Address for a new session gets determined by the burn program. My decision to use 32 block alignment is mainly motivated by the 32 block granularity of Blu-ray media. Is it the case that this information is out of band from the sector data and accessed using special device commands? The gap with DVD+R contains no payload and afaik no other useful information. Its technical reason is obscure to me. Maybe one can find an explanation in ECMA-349. To my experience the gaps of DVD+R are readable as zero bytes. (CD gaps are not readable by the normal SCSI READ command.) About all my knowledge with MMC drives and media is collected in file xorriso-*/doc/cookbook.txt which you can find in the xorriso tarball. It refers to SCSI specs SPC, SBC and MMC. Have a nice day :) Thomas -- To UNSUBSCRIBE, email to cdwrite-requ...@other.debian.org with a subject of unsubscribe. Trouble? Contact listmas...@other.debian.org
Re: How To Read Volume ID from DVD
Hi, $ growisofs -Z /dev/dvdrw1 -R -J -V volly tmp/ but although it seems absurd I can't find any way to read this volume label back once written. $ volname /dev/dvdrw1 CDROM CDROM is the default volume id of mkisofs. -V volly should have overridden that. volname works for me. Own backup formatted by xorriso: $ volname /dev/sr2 UPDATE_HOME_2008_12_09_115802 Debian CD formatted by mkisofs $ volname /dev/sr2 Debian 4.0 r0 M-A 1 Now mkisofs under control of growisofs: $ growisofs -Z /dev/sr2 -R -J -V volly /test/test ... /dev/sr2: reloading tray $ volname /dev/sr2 volly So your growisofs command seems ok. One can get the volume id from xorriso too: $ xorriso -indev /dev/sr2 21 | grep '^Volume id' Volume id: 'volly' just to make sure that the local volname has not gone bad in some way. Or make an attempt with vanilla tools: $ dd bs=1 skip=32808 count=32 if=/dev/sr2 | strings volly (ECMA-119 8.4.6 Volume Identifier (BP 41 to 72) under the assumption that the PVD is at LBA 16.) Was the media ejected and reloaded after writing ? If not, and if the media held an ISO image before then the Linux block device drive might have some old media content cached. Have a nice day :) Thomas -- To UNSUBSCRIBE, email to cdwrite-requ...@other.debian.org with a subject of unsubscribe. Trouble? Contact listmas...@other.debian.org
Re: How To Read Volume ID from DVD
Hello, On Sunday October 04 2009, m wrote to cdwrite@other.debian.org: m There's various places that discuss burning with growisofs and m specifying a volume ID, like m $ growisofs -Z /dev/dvdrw1 -R -J -V volly tmp/ m but although it seems absurd I can't find any way to read this m volume label back once written. m Is there any way to do this under Linux? Have you tried vol_id? vol_id /dev/dvdrw1 or vol_id --label /dev/dvdrw1 do it for me. Regards, Hans. jdh dot beekhuizen at duinheks dot nl --- GoldED+/LNX 1.1.5/091003 * Origin: The Wizard is using MBSE/Linux (2:280/1018) -- To UNSUBSCRIBE, email to cdwrite-requ...@other.debian.org with a subject of unsubscribe. Trouble? Contact listmas...@other.debian.org
Re: How To Read Volume ID from DVD
m mag...@gmail.com wrote: There's various places that discuss burning with growisofs and specifying a volume ID, like $ growisofs -Z /dev/dvdrw1 -R -J -V volly tmp/ but although it seems absurd I can't find any way to read this volume label back once written. volname is discussed but is worthless here: $ volname /dev/dvdrw1 CDROM Use isoinfo -o xx.iso -d Note that if you use non-asci chars in Joliet and like to add -J that you need to use the official cdrtools ftp://ftp.berlios.de/pub/cdrecord/alpha/ as th fork on seveal Linux distros is full of bugs. Jörg -- EMail:jo...@schily.isdn.cs.tu-berlin.de (home) Jörg Schilling D-13353 Berlin j...@cs.tu-berlin.de(uni) joerg.schill...@fokus.fraunhofer.de (work) Blog: http://schily.blogspot.com/ URL: http://cdrecord.berlios.de/private/ ftp://ftp.berlios.de/pub/schily -- To UNSUBSCRIBE, email to cdwrite-requ...@other.debian.org with a subject of unsubscribe. Trouble? Contact listmas...@other.debian.org
Re: How To Read Volume ID from DVD
CDROM is the default volume id of mkisofs. -V volly should have overridden that. volname works for me. Own backup formatted by xorriso: $ volname /dev/sr2 UPDATE_HOME_2008_12_09_115802 My apologies, my example indicated a first (-Z) session but should have been of a subsequent (-M) session. The explanation for why volname returned CDROM is that is apparently the default volume label when none is specified (which wasn't in the first session). I specified volly on a later session but volname and vol_id (which someone else suggested) appear to not be multi-session aware and return data only from the first session. One can get the volume id from xorriso too: $ xorriso -indev /dev/sr2 21 | grep '^Volume id' Volume id: 'volly' Thanks, I hadn't heard of this tool and indeed it works, properly returning info from the latest session. As well I see its -toc mode emits the volume IDs for each session, vs.wodim -toc which doesn't show this. Or make an attempt with vanilla tools: $ dd bs=1 skip=32808 count=32 if=/dev/sr2 | strings volly (ECMA-119 8.4.6 Volume Identifier (BP 41 to 72) under the assumption that the PVD is at LBA 16.) I had begun reading ECMA-119 last night when it appeared there was no way to do this but write my own code. My case is multi-session discs so it'll take a little more than this. I've still got to look at ECMA-168 to see how to find the start of each session. I found there are various other fields (e.g. application identifier) the image creation tools will allow you to specify yet even the relatively heavy weight tools don't appear to expose, so I'm going to write a simple tool a la volname but multi-session aware and that can report the other volume descriptor fields. -- To UNSUBSCRIBE, email to cdwrite-requ...@other.debian.org with a subject of unsubscribe. Trouble? Contact listmas...@other.debian.org
How To Read Volume ID from DVD
There's various places that discuss burning with growisofs and specifying a volume ID, like $ growisofs -Z /dev/dvdrw1 -R -J -V volly tmp/ but although it seems absurd I can't find any way to read this volume label back once written. volname is discussed but is worthless here: $ volname /dev/dvdrw1 CDROM dvd+rw-mediainfo gives other info but not the volume label. Putting the produced DVD into a Windows machine shows the volume label, no problem. Is there any way to do this under Linux? -- To UNSUBSCRIBE, email to cdwrite-requ...@other.debian.org with a subject of unsubscribe. Trouble? Contact listmas...@other.debian.org
