Quantize CD Track Markers/Splices at Zero Crossing Point?

Does anyone know if it’s possible to configure track markers to snap to the nearest zero crossing point in a waveform from the point that you place the marker? This would be a nice little time saver when placing markers on songs that have a crossfade so that when they’re split, it’s a a perfect separation with no DC offset between the two files.

Click here to set the edit cursor on a zero crossing point:
then insert your marker at the cursor.

Just remember that despite where you place the marker, if and when you make a CD and/or DDP, the marker will shift ever-so-slightly to the nearest CD frame anyway. This isn’t a limitation of WaveLab but the nature of CD/DDP.

This is why after I have my markers where I want them, I run the CD Wizard one last time to “Quantize Makers To Nearest CD Frame” with all other options in the CD Wizard turned off.

This will make sure that whether you render WAV/AAC/mp3 files from the montage, or make a CD/DDP that the makers and tracks will be precisely the same which is something that can be important with albums where songs overlap or crossfade.

Just something to consider. If you don’t care about anything CD related, maybe there is no need to quantize again.

+1. I don’t know of any continuous live albums on CD that have Track markers all at zero crossing. It’s nearly impossible to reconcile zero crossing and required CD track quantize.

What’s the best way to address DC offset for MP3’s that are going on a streaming service where there is a physical break from track to track? Is it to place some kind of 1ms fades on the ends to prevent pops at the ends/beginning of songs where you spliced a crossfade? That was my reasoning for wanting a marker to quantize to the zero crossing point. If you listen to some Pink Floyd on Spotify for instance, where songs are crossfaded, there is never a pop at the ends of the tracks. Did the mastering engineer manually find the zero crossing point or apply fades to achieve that?

I doubt that the mastering engineer bothered to get zero crossings. Spotify uses Ogg but Ogg is still subject to imperfection in some players in my experience, so maybe they’ve just gotten it pretty perfect in some players like Spotify and iTunes.

You could buy MP3 or AAC of a couple of the tracks from the Pink Floyd album from Amazon or iTunes and see where they’re split, but I’m guessing they’re not zero crossings.

Make MP3’s and AAC’s of your tracks with zero crossing and not, and play them continuously in iTunes and a few other players to see what you get.

My Amazon Music Player produced pops =(. That’s what lead me to post this. I figured that if the ends of the files had zero crossing points that it would correct the issue for not only that platform but all others as well?

Do you mean you have an album selling on Amazon that pops? Zero crossings certainly wouldn’t hurt, but I found most differences mainly due to different players (ymmv). It would be nice if zero crossings fixed it and they would allow you to resubmit. Does the Amazon Music Player play non-store files too?

I don’t have an album for sale on Amazon. I have clients that are getting ready to release their project and Amazon will be one of the distributors so I want to make sure I am sending them out into the world with a product that is not going to have issues. Amazon allows me (everyone?) to upload my own MP3’s to their cloud (up to 250 songs) and have them available to stream as part of my existing library of stuff I have purchased. This is where I tested the songs in question and confirmed the pops between tracks where the ends did not terminate at the zero crossing point.

So the pops have been confirmed in both the Amazon Music Player and in iTunes when I load them up and listen, so I went ahead and purchased Pink Floyd’s “The Division Bell” album from Amazon.

I listened to this album on Spotify and there are no pops between tracks where a cross-fade and split was applied. Then I listened in my Amazon Music Player, streaming from their cloud. Also no pops between tracks (and even better, no “gaps” like you hear on Spotify).

I then downloaded the MP3’s of tracks 1 and 2 where there is a cross-fade and split and looked at the waveforms where the split occurs. BOTH end at the zero crossing point and appear to have micro-fades applied (see screenshot). So at this point, am I to assume that in order to pull this off for every streaming format out there, that I need to apply these same micro-fades (150 microseconds)? I just can’t let this project be released and have my clients coming back to me asking “WTF is up with the ‘pops’ in between songs?”.

This is interesting. Keep in mind that mp3/AAC encoders add a small amount of silence at the start and end of each encoded file. You can test this by making a test tone that has an abrupt start and end as a WAV file, and then encode it to mp3 or AAC.

You’ll see roughly 20 to 40 milliseconds added to the start and end to the file. I’m not sure if certain codecs and settings produce different amount of this but you may want to take this into consideration as you examine and prepare various files.

orangeoctane, sorry if I’ve complicated this, but as Justin said silence is added in the encodes/decodes so what you’re seeing doesn’t necessarily indicate zero crossing, (although the level on the Pink Floyd is so low there it’s hard to tell anything really). I’ve gotten the files and there is silence added, and not necessarily micro fades to silence in the original master wavs.

Have you tried zero crossing with your files and gotten better results? That’s what I would do if it’s a digital only release. Make MP3, AAC and Ogg in Wavelab and try them all in different players.

Strange that Spotify plays with gaps because the players should compensate. That’s just as bad as pops to me. Wavelab will also play with gaps in the sound if you just butt the decoded files together, because of the added silences, but it’s not made to do otherwise.

Maybe there is a hipper and smarter way to do things nowadays but I just make it so the WAV files (and of course DDP) are truly seamless. To my ears, anything else would be a noticeable gap/glitch if you really listen close. I’ve found that different media players handle things differently and are not entirely predictable. Even older and newer versions of iTunes handle seamless/gapless tracks differently. There are many factors including if the song is truly streaming, or if it’s downloaded to the device already.

I think if you have it right at the source (the master WAV files), the rest will fall into place to the best of that format’s ability.

I’d love to hear what others are doing though as maybe there is a better way.

When you place a split marker in the montage to separate 2 tracks that are crossfaded, the WAV and DDP will be seamless and sound perfect on the CD. My issue is the resulting pops that I hear in iTunes playback and Amazon Music Player playback when uploading MP3/AAC and trying to explain to my clients why it’s happening with their project but not other commercially released albums with crossfades. Just wondering what’s the “best practice” amongst mastering engineers to address this issue. Surely there is an “accepted” or “standardized” method that’s being used?

If The Division Bell is playing with gaps on Spotify, that’s wrong, so it does happen on other releases. Honestly there are probably others. There was a lot of talk about issues with Dark Side Of The Moon in the past.

If zero crossing makes a difference (and I’m not totally convinced it does in all cases), the most you can do to cover all bases (cd and lossy files, since the lossy files are probably going to be made from the cd master) is to quantize the cd markers, and then redraw the waveform to cross at zero at those markers. Try it.

Somebody might recommend it but I don’t think it’s a standard practice.

The gaps on Spotify are present for every song on every album they have in their entire library, at least on the web player. Since that is a common denominator for all listening users I don’t have to explain that to clients. It is what it is. But pops on iTunes and Amazon (silence gaps or not) aren’t going to cut it. I think I’m going to have to offer my clients versions that have ZCPs or have microfades on the ends so that they can choose what they’re comfortable with.

Makes sense.

One other factor I hadn’t thought of til now is the codec being used to make the MP3. Of course in Wavelab most use the Fraunhofer codec, but Amazon uses LAME to make their MP3’s and there might be different silence metadata involved, so that’s one other thing to try in Wavelab - the LAME codec to make the MP3s.

Amazon used to use the LAME 320kbps CBR settings to make their MP3’s, but now uses LAME VBR. I haven’t checked The Division Bell files to see which they are, so it’s probably worth trying LAME with both settings. It’s entirely possible the files could act differently than the Fraunhofer when played back in the Amazon Player and in iTunes.

I’ll have to check that out. I appreciate the replies!

PG - Just a note on this. That feature isn’t available in Montage view, only Editor view. It would be handy if it could be included in the marker functionality for montages in a future update.

OKAY!!! So I’ve spent about 8 hours now testing and troubleshooting this issue!

The ONLY way I have found to make this work acceptably is to find the nearest ZCP at the end of the file that’s further away than 1ms from the end. From there, I have to apply a fade to the end of the file so that whatever is in that 0ms-2ms area terminates exactly at the ZCP. I have to do this manually for each channel if the ZCP is different for each. If I try and apply this fade on the ZCP with less than 1ms, the pop still produces. What I end up with is about 1.5ms of fade out on one file and 1.5ms of fade in on the other. So yes, I am losing some percentage of that 3ms of original content there but I am eliminating the pop between tracks, regardless the player I am using. It’s hard to hear it, even for trained ears like ours in our field.

It’s the lesser of all evils at the point, so I am rolling with it until somebody points out a better way to eliminate the pops for all player scenarios.