# Should I merge recordings with just a small length difference? **URL:** \ **Category:** MusicBrainz\ **Created:** [April 30, 2022, 3:32pm UTC](https://community.metabrainz.org/t/should-i-merge-recordings-with-just-a-small-length-difference/583169 "2022-04-30T15:32:58Z")\ **Posts on this page:** 17\ **Page:** 1
**Author:** ![indy133](https://community.metabrainz.org/user_avatar/community.metabrainz.org/indy133/32/36101_2.png) [@indy133](https://community.metabrainz.org/u/indy133)\ **Post date:** [April 30, 2022, 3:32pm UTC](https://community.metabrainz.org/t/should-i-merge-recordings-with-just-a-small-length-difference/583169/1 "2022-04-30T15:32:58Z")
There are many recordings which seem to be the same except for a small length difference, eg. ![Vollbildaufzeichnung 30.04.2022 172924](https://community.metabrainz.org/uploads/default/original/3X/c/d/cd70ebaf08d50640204613ffe43a58c21cdd3313.jpeg) [https://musicbrainz.org/work/5082106c-431f-4a45-9278-1cc0bf549c9d](https://musicbrainz.org/work/5082106c-431f-4a45-9278-1cc0bf549c9d) How do we know when to merge these without any additional recording info? ---
**Author:** ![ernstlx](https://community.metabrainz.org/user_avatar/community.metabrainz.org/ernstlx/32/27258_2.png) [@ernstlx](https://community.metabrainz.org/u/ernstlx)\ **Post date:** [April 30, 2022, 4:27pm UTC](https://community.metabrainz.org/t/should-i-merge-recordings-with-just-a-small-length-difference/583169/2 "2022-04-30T16:27:34Z")
It’s a case by case decision, but in this case I would definitely merge. Look for fingerprints. The fingerprint of the 4:01 recording is already part of the other one. You can try to compare the AcoustIDs from these tracks, but with this it’s quite obvious. But be aware that there are sometimes different versions which may look similar (e.g. explicit and clean). ---
**Author:** ![indy133](https://community.metabrainz.org/user_avatar/community.metabrainz.org/indy133/32/36101_2.png) [@indy133](https://community.metabrainz.org/u/indy133)\ **Post date:** [April 30, 2022, 4:57pm UTC](https://community.metabrainz.org/t/should-i-merge-recordings-with-just-a-small-length-difference/583169/3 "2022-04-30T16:57:28Z")
> [@ernstlx](#): > > But be aware that there are sometimes different versions which may look similar (e.g. explicit and clean). In these cases there should be a disamb field entry, but I guess it’s just an illusion to think that this is always done correctly 😉 ---
**Author:** ![IvanDobsky](https://community.metabrainz.org/user_avatar/community.metabrainz.org/ivandobsky/32/11785_2.png) [@IvanDobsky](https://community.metabrainz.org/u/IvanDobsky)\ **Post date:** [April 30, 2022, 5:31pm UTC](https://community.metabrainz.org/t/should-i-merge-recordings-with-just-a-small-length-difference/583169/4 "2022-04-30T17:31:33Z")
It is easier to merge Various Artist collections like that as it is unlikely a band will record something different for a compilation. Though I have seen cases of something like a charity album getting special recordings. ---
**Author:** ![elomatreb](https://community.metabrainz.org/user_avatar/community.metabrainz.org/elomatreb/32/44009_2.png) [@elomatreb](https://community.metabrainz.org/u/elomatreb)\ **Post date:** [April 30, 2022, 5:37pm UTC](https://community.metabrainz.org/t/should-i-merge-recordings-with-just-a-small-length-difference/583169/5 "2022-04-30T17:37:18Z")
A one second difference may also just be an artifact of different rounding methods (some tracklists round their track durations towards 0, while others will display 4 minutes and 600 milliseconds as 4:01). ---
**Author:** ![yindesu](https://community.metabrainz.org/letter_avatar_proxy/v4/letter/y/b77776/32.png) [@yindesu](https://community.metabrainz.org/u/yindesu)\ **Post date:** [April 30, 2022, 7:20pm UTC](https://community.metabrainz.org/t/should-i-merge-recordings-with-just-a-small-length-difference/583169/6 "2022-04-30T19:20:13Z")
Be very careful with AcoustID fingerprints. I have multiple examples of recordings of **different lengths** being grouped together, despite significant differences in the first 120 seconds: [https://acoustid.org/track/aef83d93-e4da-43c2-b0fd-c5277162e075](https://acoustid.org/track/aef83d93-e4da-43c2-b0fd-c5277162e075) [https://acoustid.org/track/af660683-4ca9-4f87-83bb-7c023e9419f5](https://acoustid.org/track/af660683-4ca9-4f87-83bb-7c023e9419f5) Here’s another with a significant length difference, but the audio differences lie beyond the first 120 seconds: [https://acoustid.org/track/a0fb4bc2-9ac8-49f8-99a8-f07f4441100e](https://acoustid.org/track/a0fb4bc2-9ac8-49f8-99a8-f07f4441100e) ---
**Author:** ![indy133](https://community.metabrainz.org/user_avatar/community.metabrainz.org/indy133/32/36101_2.png) [@indy133](https://community.metabrainz.org/u/indy133)\ **Post date:** [April 30, 2022, 7:22pm UTC](https://community.metabrainz.org/t/should-i-merge-recordings-with-just-a-small-length-difference/583169/7 "2022-04-30T19:22:09Z")
> [@ernstlx](#): > > Look for fingerprints. The fingerprint of the 4:01 recording is already part of the other one. You can try to compare the AcoustIDs from these tracks Besides: I’ve always been a vinyl collector. So, after decently bemoaning my fate, I’ll delve into what the terms “fingerprint” and “AcoustID” mean. I’ve not the slightest clue. Thx for introducing me 😉 ---
**Author:** ![ernstlx](https://community.metabrainz.org/user_avatar/community.metabrainz.org/ernstlx/32/27258_2.png) [@ernstlx](https://community.metabrainz.org/u/ernstlx)\ **Post date:** [April 30, 2022, 9:29pm UTC](https://community.metabrainz.org/t/should-i-merge-recordings-with-just-a-small-length-difference/583169/8 "2022-04-30T21:29:32Z")
> [@indy133](#): > > Besides: I’ve always been a vinyl collector. AcoustIDs should be format independent. An acoustID contains several fingerprints of similar recordings. If you submit a fingerprint through Picard it is compared with similar fingerprints in an existing AcoustID. If it’s very similar it generates the same fingerprint, but depending on format or quality it may have a separate fingerprint, but it will be grouped in the same AcoustID. If it’s not that similar, a new AcoustID is created. (in theory all fingerprints of the same recording should go to the same AcoustID, but that’s obviously not always true) If you click on an AcoustID (Recording\Fingerprints tab) you go to [https://acoustid.org](https://acoustid.org) where you can compare two fingerprints. You can shift the the second fingerprint (compared to the first one) up and down until the right bar turns black (the difference between the first 2 bars): ![Bildschirmfoto_2022-04-30_23-22-00](https://community.metabrainz.org/uploads/default/original/3X/6/7/6748c0366f3921a6b21426b4318c451bf7905e77.jpeg) In this example the fingerprints have no perfect match in any position, but they are similar enough to end up in the same AcoustID. ---
**Author:** ![ernstlx](https://community.metabrainz.org/user_avatar/community.metabrainz.org/ernstlx/32/27258_2.png) [@ernstlx](https://community.metabrainz.org/u/ernstlx)\ **Post date:** [April 30, 2022, 10:06pm UTC](https://community.metabrainz.org/t/should-i-merge-recordings-with-just-a-small-length-difference/583169/9 "2022-04-30T22:06:34Z")
What I meant with… > [@ernstlx](#): > > You can try to compare the AcoustIDs from these tracks… If there are multiple acoustIDs linked to a recording, you can try to compare fingerprints of each acoustID and look if they are similar enough to belong to the same recording, because many submitted fingerprints are false submissions of incorrectly tagged files. Also look at the track lengths of the files which submitted the fingerprints. If they are completely different, they will hardly belong to the same recording. And, what @yindesu pointed out is that different lengths don’t prevent the fingerprints from going to the same acoustID, because only the first 120 seconds are used for the fingerprint. ---
**Author:** ![yindesu](https://community.metabrainz.org/letter_avatar_proxy/v4/letter/y/b77776/32.png) [@yindesu](https://community.metabrainz.org/u/yindesu)\ **Post date:** [April 30, 2022, 10:11pm UTC](https://community.metabrainz.org/t/should-i-merge-recordings-with-just-a-small-length-difference/583169/10 "2022-04-30T22:11:57Z")
It’s worse than that - 2/3 of my examples are shorter than 120 seconds (2:00). ---
**Author:** ![ernstlx](https://community.metabrainz.org/user_avatar/community.metabrainz.org/ernstlx/32/27258_2.png) [@ernstlx](https://community.metabrainz.org/u/ernstlx)\ **Post date:** [April 30, 2022, 10:22pm UTC](https://community.metabrainz.org/t/should-i-merge-recordings-with-just-a-small-length-difference/583169/11 "2022-04-30T22:22:12Z")
I’ve noticed that too. Shorter fingerprints exist in the same acoustID, although there are some longer than 2:00. Maybe they are accepted as partial submissions and compared with what’s there. (?) ---
**Author:** ![UltimateRiff](https://community.metabrainz.org/user_avatar/community.metabrainz.org/ultimateriff/32/47799_2.png) [@UltimateRiff](https://community.metabrainz.org/u/UltimateRiff)\ **Post date:** [May 1, 2022, 5:38am UTC](https://community.metabrainz.org/t/should-i-merge-recordings-with-just-a-small-length-difference/583169/12 "2022-05-01T05:38:14Z")
> [@IvanDobsky](#): > > It is easier to merge Various Artist collections like that as it is unlikely a band will record something different for a compilation. I wanted to add that _sometimes_ they will do this, as @sound.and.vision showed in [another thread](https://community.metabrainz.org/t/long-format-videos-of-interest-to-the-mbz-nerd-community/578159/11). ideally, these should also be disambiguated though. one other thing to look for is conflicting relationships on the recordings in question, say one is a live recording from say, 1989, and the other is a live recording from 1995. I’ve just recently [split a recording](https://musicbrainz.org/edit/89181977) for similar reasons. ---
**Author:** ![indy133](https://community.metabrainz.org/user_avatar/community.metabrainz.org/indy133/32/36101_2.png) [@indy133](https://community.metabrainz.org/u/indy133)\ **Post date:** [May 1, 2022, 5:41am UTC](https://community.metabrainz.org/t/should-i-merge-recordings-with-just-a-small-length-difference/583169/13 "2022-05-01T05:41:45Z")
> [@ernstlx](#): > > AcoustIDs should be format independent. An acoustID contains several fingerprints of similar recordings. If you submit a fingerprint through Picard Thank you very much for explaining, but of course this means a lot of work in case of vinyls 😉 ---
**Author:** ![ernstlx](https://community.metabrainz.org/user_avatar/community.metabrainz.org/ernstlx/32/27258_2.png) [@ernstlx](https://community.metabrainz.org/u/ernstlx)\ **Post date:** [May 1, 2022, 8:05am UTC](https://community.metabrainz.org/t/should-i-merge-recordings-with-just-a-small-length-difference/583169/14 "2022-05-01T08:05:57Z")
> [@indy133](#): > > this means a lot of work in case of vinyls Why? There is nothing different with vinyls. If I go back to your example: One acoustID is linked to both recordings. The “4:00 recording” has three more acoustIDs. You may like to compare them to the first one: Click a fingerprint from the first acoustID (both recordings). If there are many fingerprints, pick one with many submissions (although they will all be very similar, because they were grouped in the same acoustID) → copy/paste a fingerprint number from another acoustID into the “compare” field at the bottom of the page → click compare → move up and down to find a “perfect” match… You will see, that the others are also similar, although one of them has section with no good match, maybe because of very poor audio quality, maybe because of manipulation (remixed?). But usually different versions are clearly different. And another thing: If you look at the number of submissions, those with little similarity have only 1 and 2 submissions. You can forget about them → merge! ---
**Author:** ![indy133](https://community.metabrainz.org/user_avatar/community.metabrainz.org/indy133/32/36101_2.png) [@indy133](https://community.metabrainz.org/u/indy133)\ **Post date:** [May 1, 2022, 8:11am UTC](https://community.metabrainz.org/t/should-i-merge-recordings-with-just-a-small-length-difference/583169/15 "2022-05-01T08:11:15Z")
> [@ernstlx](#): > > Why? Well I guess I have to make a recording from my vinyl to get a fingerprint .-) ---
**Author:** ![ernstlx](https://community.metabrainz.org/user_avatar/community.metabrainz.org/ernstlx/32/27258_2.png) [@ernstlx](https://community.metabrainz.org/u/ernstlx)\ **Post date:** [May 1, 2022, 8:14am UTC](https://community.metabrainz.org/t/should-i-merge-recordings-with-just-a-small-length-difference/583169/16 "2022-05-01T08:14:06Z")
Ah, I understand… Only in case of conflicting acoustIDs (clearly different). Then you should probably submit your acoustID to make sure which one is the correct acoustID for this recording. It’s not necessary in your example. ---
**Author:** ![ernstlx](https://community.metabrainz.org/user_avatar/community.metabrainz.org/ernstlx/32/27258_2.png) [@ernstlx](https://community.metabrainz.org/u/ernstlx)\ **Post date:** [May 1, 2022, 10:18am UTC](https://community.metabrainz.org/t/should-i-merge-recordings-with-just-a-small-length-difference/583169/17 "2022-05-01T10:18:22Z")
> [@UltimateRiff](#): > > one other thing to look for is conflicting relationships on the recordings in question, say one is a live recording from say, 1989, and the other is a live recording from 1995. Yes, and these are cases when acoustIDs prove to be most helpful. The 89 recording surely has other acoustIDs than the 95 recording. Of course, if they were already merged, and if you try to untangle the recordings, there’s much work ahead 😉