On Sunday, 4 January 2026 13:30:52 Greenwich Mean Time Michael wrote: > On Sunday, 4 January 2026 12:42:45 Greenwich Mean Time Nuno Silva wrote: > > On 2026-01-04, Michael wrote: > > > On Saturday, 3 January 2026 16:44:56 Greenwich Mean Time Alan Mackenzie > > wrote: > > >> On Fri, Jan 02, 2026 at 15:44:06 +0000, Alan Mackenzie wrote: > > >> > On Fri, Jan 02, 2026 at 10:43:05 +0000, Michael wrote: > > >> > > On Thursday, 1 January 2026 21:46:27 Greenwich Mean Time Alan > > >> > > Mackenzie > > > > > > wrote: > > >> > > > Hello, Gentoo. > > >> > > > > > >> > > > Happy New Year! > > >> > > > > > >> > > > On my (no longer quite so) new PC, I've still not managed to get > > >> > > > audio > > >> > > > CDs to play properly. Originally I was using the program > > >> > > > aqualung, > > >> > > > but > > >> > > > that gave a constant crackle on top of the music, making it > > >> > > > unusable. > > >> > > > (But it was fine on my old PC.) > > >> > > > > > >> > > > I've since moved to deadbeef (officially called DeaDBeeF), which > > >> > > > though > > >> > > > much better is still not right. What I get now on playing a CD > > >> > > > is: > > >> > > > (i) the first track of the CD gets ~6 seconds of crackle at the > > >> > > > start; > > >> > > > (ii) at each subsequent track (regardless of whether there are > > >> > > > any > > >> > > > actual > > >> > > > > > >> > > > gaps between the tracks) there is about 2 seconds of crackle at > > >> > > > the > > >> > > > beginning; > > >> > > > > > >> > > > (iii) if I pause the playback and restart it, there is no extra > > >> > > > crackle; > > >> > > > (iv) on moving the playback to a random part of the track, I get > > >> > > > the > > >> > > > ~6 > > >> > > > > > >> > > > seconds of crackle; > > >> > > > > > >> > > > (v) there are random moments of crackle in the middle of tracks, > > >> > > > too, > > >> > > > > > >> > > > often ~6 seconds after an audible drive head movement. > > >> > > >> [ .... ] > > >> > > >> > I think I am just going to buy a new drive. At ~25 Euros, it's just > > >> > not > > >> > worthwhile trying all these things on the current one. > > >> > > >> Well, I've bought and installed a new drive (made by ASUS) and it > > >> hasn't > > >> helped in the slightest. :-( > > >> > > >> Maybe modern DVD drives just aren't capable of reading audio CDs > > >> properly. After moving the read head to some position on the CD, it's > > >> necessary to start reading the sectors accurately straight away. Maybe > > >> these newer drives positioning of the heads leaves them wobbling, or > > >> something, and rely on software error correction to reread erroneous > > >> sectors. On playing an audio CD, I don't think sectors get reread at > > >> all, just erroneous values get transmitted to the DAC. > > >> > > >> Or something like that. > > >> > > >> [ .... ] > > >> > > >> > Maybe I'll get this sorted out in the next week, or so. Thanks > > >> > again. > > >> > > >> Or, maybe not. :-( > > > > > > Unless I've misunderstood something, through a process of elimination > > > you > > > have concluded your audio CD crackling problem and DVD sector reading > > > problem is caused by the drive itself. Your old PC DVD drive exhibits > > > no > > > such problem, but the new PC's DVD drive and the ASUS replacement you > > > just bought both show the same symptoms. > > > > > > In your process of elimination, did you also replace the DVD drive cable > > > on > > > the new PC? > > > > > > Is the audio CD crackling evident both on new (factory recorded) audio > > > CDs > > > and writeable CDs you burned yourself? If the latter, did you try more > > > expensive disc brands and different (slower & then higher) burn speeds > > > to > > > see if the crackling goes away? > > > > > > Another trick which may work is to increase the cache size on the media > > > player, e.g. 2x, 4x, 8x. It should give more time for the drive to > > > perform > > > its error correction gymnastics and hopefully overcome any media error. > > > > > > The crackling/reading problem at the start of CD/DVDs can happen because > > > of > > > light scatter from the transparent edge to the initial data tracks. I > > > recall reading somewhere if you use a black marker pen at the back of > > > the > > > transparent region, you can fix this problem. The difference between > > > old > > > and new PC drives could be related to cheap-ification in components, > > > lower energy laser, etc. > > > > > > If the new drive doesn't address your problem, hopefully you should be > > > able to return it. > > > > I'm not even sure what's the current state of affairs with drives > > playing CD-DA themselves, but: > > > > This is all with playback outside the drive? (That is, reading the CD-DA > > data and playing it.) Or is there any chance part of the problem is when > > the drives themselves read and play the CD? (I.e. audio output from the > > drive to the sound card. - But is playback speed (which you've > > mentioned) something that can be changed in this kind of playback?) > > > > (Also, doesn't CD-DA have some amount of error correction data?) > > I don't know much about the details of error correction mechanism, but as > far as I know the (linear) data read speed is constant. This means as the > audio CD is read from the centre to the outer tracks the physical > rotational speed ought to slow down. > > From what I have observed with some 'faulty' CDs here, a larger buffer will > allow more time for the error-correction data and initial music data to be > read into the buffer, verified, re-read/corrected and eventually submitted > to the DAC, before the next ECC/data block is read and processed. More > time available (larger cache) ought to improve this process, and less time > would probably hinder it. I have observed problematic CDs take longer > scanning and rescanning the start of the track before they start playing > it. In my experience this applies both to audio and data CDs. > > However, if there are no differences between media player software and cache > settings used on two different hardware (old PC Vs new PC), then logically > the hardware becomes suspect.
Just came across this useful explanation after a quick search by people who know what they are talking about: https://electronics.stackexchange.com/questions/735526/how-do-forward-error-correction-and-read-ahead-buffers-work-in-a-compact-disc-pl
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