Hey Thomas,
right after starting xfburn, it won't even let me choose the speed nor burning mode (both grayed off). When I choose an ISO and press burn, xfburn complains about "this writing mode is not supported yet". When I click the tiny icon beside "DVD-R sequential recording", the former grayed menus for speed and writing mode are now available. Then I can also start the writing process, and it does not go to max speed and completes successfully. This is all very confusing. I have no clue what's going on here, and I am so sorry for bothering you with that. Have a nice day Werner -----Original-Nachricht----- Betreff: Re: After upgrade to Debian Bullseye, I am not able to burn DVDs. Datum: 2021-11-24T22:19:53+0100 Von: "Thomas Schmitt" <scdbac...@gmx.net> An: "999...@bugs.debian.org" <999...@bugs.debian.org> Hi, > I tested at first the live CD of Debian 10. > K3B also disrespects the speed setting. But the process seems to > adjust the speed automatically. 18x was starting speed and it was > reduced, so that the resulting speed was 4x. An initial utopic speed is not necessarily the fault of the burn program. The drive's buffer accepts data with high speed until it is full, so only after 2 or 4 MB the observed speed drops to the real speed of burning. DVD-R usually get burned with constant angular velocity (rounds per minute), so that the linear speed reaches the desired speed only at the end of burning. > K3B under Debian 11 still behaves as before. > Setting speed is totally ignored, the burner makes noise like a starting > jet, and finishes with error and overall speed of 18,4x. I really wonder what might have changed in K3B. You could try with Xfburn again. Its source code looks like it would ask libburn to set a speed. Regrettably i find no hints in the web how to increase Xfburn's verbosity so that you get to see the debug message Set speed to ... kb/s which is to see immediately before the call to burn_drive_set_speed(). See: https://sources.debian.org/src/xfburn/0.6.2-1/xfburn/xfburn-burn-audio-cd-composition-dialog.c/?hl=299#L299 > Unfortunately, I am not able to reproduce the error again with xorrecord. I count this as a piece of luck for me. :)) It is not normal that a drive produces bad results if it is asked for high speed or if it is not asked for low speed. So whatever K3B or growisofs (*) do wrong, your drive did its share to cause the failure. (*) It might be that K3B uses cdrskin instead of growisofs. But i have no idea how to find out which of both is in charge for DVD. (cdrskin is the cdrecord compatibility wrapper of libburn.) Have a nice day :) Thomas
