Re: Skip Silence DSP accidentally enabled for months while ripping music
Reply #8 – 2018-10-23 20:01:37
The threshold you set pretty much means only absolute digital silence has been stripped. I'd think majority of your files are affected as non-gapless CDs generally have two seconds of silence between tracks. If you aren't a perfectionist having an altered collection may not be too bad, but I know I would rerip the tracks. I wouldn't worry too much about missing digital silence; depending on how your drive interprets track markers you may have never been able to rip them anyway. The start of the audio portion of a CD track is technically its index 01. The two-second silence before the first track on a disc, if there is one, is technically the pregap (index 00) before the track. The Red Book spec was that it should be at least two seconds (150 frames) at the start of the CD and a similar leadout at the end - gaps between tracks is somewhat more optional. Nowadays it's not really strictly adhered to. CD players will play the pregap (and if they're designed strictly to the Red Book spec, they will display a minus time countdown, then start counting from 0 when the audio track begins). It's a bit hit and miss these days. Despite the standard being clear on pregap, some CD players nowadays don't bother them and some can't even 'rewind' into the pregap. Nowadays it seems people discard the pregap when ripping, unless they care about preserving the duration of songs. Hacking the spec (using Sequioa, Sonoris DDP creator, CDRWIN or similar cuesheet creation tools) you can produce an audio CD with audio in the index 00 - you end up with 'hidden tracks', which you can't skip to (unless your CD player lets you specify both track and index) -- but you can listen to them if you let the CD play through. The stealthiest hidden tracks were hidden at index 0 of track 1 (making them impossible to listen to unless you rewind into them from the start of track 1) or at the very end of a long pregap which was otherwise digital silence. Whenever I rip CDs, I set my ripper up so that if there's any non-zero duration pregap detected for a track in the TOC and PQ metadata, it appends the same duration to the end of the previous track. That means they'll play back correctly when listening in 'album mode', but not add digital silence to the start of the following track. If in doubt, rip the CD as FLAC + cuesheet (preserving gaps), and play back using the cuesheet. You'll be able to see any pregaps by inspecting the cue, and you'll be able to subsequently produce individual files from the FLAC+CUE by splitting on index markers. Nowadays with effectively-gapless albums, pregap / pause mark / track end marks are not really used. Apparently Florence and the Machine - 'Lungs' and The Script - 'The Script' CD albums are recent issues with some non-zero gaps between tracks. I think I probably have about one- or two-dozen CDs out of my whole collection which use non-zero pregaps. It was a thing in the 80s and early 90s but it fell out of fashion as people realised they could be more creatively interesting by doing 'gapless' tracks and inserting their own transitions between tracks.