Left - Right channel delay offset on some ripped tracks

[lucidlighting]

When ripping MDs using homebrew download, some tracks have the left channel delayed by about 12ms in relation to the right channel. There doesn't seem to be a pattern as to which tracks have this issue. Some discs it's about 3 of 12 tracks and others it's half of them. Re-ripping the same disc produces the same results. I'm using a Sony MZ-N510, Edge on Windows 10

[asivery]

Hello @lucidlighting, This is a known issue with the ATRAC stream stitching algorithm. You can fix these files with this: http://testing.minidisc.wiki/channelfix.html Though because the app doesn't know if the file is damaged or not, so if you pass a working file through this, you'll break it.

[woookash]

@lucidlighting question: how do you detect if a file has the issue or not?

[lucidlighting]

@lucidlighting question: how do you detect if a file has the issue or not?

Hi @woookash I listen to the track! The delay messes with the stereo image. A signal that is equal in both L&R, will normally sound like it's 'inside' your head, (through headphones). With a slight delay on one channel, it sounds like it's 'outside' your head.

Some tracks are deliberately mixed with a L-R offset, to 'widen' the stereo image. So it's not always immediately obvious in some tracks. But with other tracks, it ruins the stereo image completely.

You can also compare the ripped track to the original minidisc playback. This makes it very obvious when directly comparing the two (especially through headphones).

asivery provided a tool to fix the tracks above. A few ripped tracks didn't play at all in VLC, but this tool also fixed this. Sometimes I had to run the file through more than once. Which asivery said didn't make sense that this worked! However it did fix all the tracks that I threw at it. Many thanks @asivery for your excellent work on the Web MiniDisc Pro app.

[woookash]

Thanks a lot for your feedback @lucidlighting I now stumbled upon a disc where one (longer, 40 min) track was ripped, and..some sections of it have the delay, others no :(

[tjjq44]

Hi, is there any hope that this delay bug will be fixed in a future revision or is it impossible?

[tjjq44]

I now stumbled upon a disc where one (longer, 40 min) track was ripped, and..some sections of it have the delay, others no :(

I experienced the same issue, I downloaded a 23 minutes track to my PC and the beginning has delay but not the whole song. Using "channelfix" fixes the beginning of the song of course but add delay later in the song while this part was ok before :'(

[asivery]

@tjjq44 @woookash I am working on fixing this bug, but unfortunately haven't had much luck with it. My main problem is that I cannot get it to reproduce on my hardware. In the next version I'll try to make it possible to 'channelfix' the section independently. That will hopefully partially mitigate the bug for now.

[tjjq44]

My hardware has nothing really special however… it’s a good old MZ-N510 portable MD recorder ;)

[asivery]

@tjjq44 Are you able to reproduce the bug reliably? If so, can you please visit https://testing.minidisc.wiki/webminidisc-testing and see if it still is an issue there? Thanks in advance.

[tjjq44]

Hi I tried again ripping various tracks with the new software version you linked above : delay bug seems to have gone out!! Also when I convert .aea to wav using foobar2000 no error anymore. Still have to test it more thoroughly, but it's promising ;)

[asivery]

@tjjq44 I'm glad it's better, unfortunately I have still managed to find some corner cases that break things...

As I've said above, this is also a feature that's coming - with this enabled, it's possible to export audio in a format that keeps internal markers and will allow the audio to be reconstructed later.