Apple Seeds iTunes 10.5.1 Beta 2 for Continued iTunes Match Testing

[bookemdano]

Wasn't purchased music, and even if it was, at 256k, it obviously wasn't an old drm'ed track so authorizing is a moot point.

You said "My two ineligible tracks are 256k AAC files that were actually previous matches from an older beta."

I figured the reason those tracks were ineligible were because they were sourced from iTunes Match. As in, those were tracks you originally had in a different format (lower quality?) and you downloaded HQ copies from iTunes Match.

My suspicion is that you cannot then use those iTunes Match-sourced tracks to match again (now that all match data was deleted x number of times). In other words, those two tracks are "Not eligible" because iTunes knows they came from iTunes Match. If you were to scan the original music files those were sourced from then that would work.

That's my theory anyway.

 

[Senseotech]

You said "My two ineligible tracks are 256k AAC files that were actually previous matches from an older beta."

I figured the reason those tracks were ineligible were because they were sourced from iTunes Match. As in, those were tracks you originally had in a different format (lower quality?) and you downloaded HQ copies from iTunes Match.

My suspicion is that you cannot then use those iTunes Match-sourced tracks to match again (now that all match data was deleted x number of times). In other words, those two tracks are "Not eligible" because iTunes knows they came from iTunes Match. If you were to scan the original music files those were sourced from then that would work.

That's my theory anyway.

Then the other 200-300 tracks that are previous matches would have been invalid as well, but they aren't.

 

[TexasTexan]

My suspicion is that you cannot then use those iTunes Match-sourced tracks to match again (now that all match data was deleted x number of times). In other words, those two tracks are "Not eligible" because iTunes knows they came from iTunes Match. If you were to scan the original music files those were sourced from then that would work.

That's my theory anyway.

From what I read, it seems that your theory is based he downloaded the two tracks after they were matched before. I don't think he ever stated that he downloaded them to replace lower bitrate tracks, just iTunes matched them before and not now.

Matching should get better, not worse, right? I really wish I knew how many of my tracks were matched in the last beta. Watching my bandwidth as things upload, even though iTunes only says uploading artwork, it seems to sometimes to be uploading the track as well, even though it never says it is. It is uploading alot of just artwork alone at times though.

 

[milo]

Interesting about not matching super low bitrate songs. How did the test go upconverting to a higher bitrate, did it match them then? If that's the case then that particular limitation seems like a pretty pointless one that's easily worked around.

 

[TexasTexan]

Interesting about not matching super low bitrate songs. How did the test go upconverting to a higher bitrate, did it match them then? If that's the case then that particular limitation seems like a pretty pointless one that's easily worked around.

I am still uploading items into the cloud so I haven't had a chance to test it myself. Someone else was going to test it but didn't see an answer yet. Another test I want to run is in the case of an mp3 not being matched. I want to convert some to aac and see if they are. I wonder if I can convert the lower bitrate mp3s into higher bitrate aac?

From watching the upload, songs are uploaded at the same time as the album art and other times it is just the album art. If a track is matched, shouldn't itunes have the album art already? Most of them should have been downloaded from iTunes anyways. Seems like extra effort and storage on their end.

 

[Tinmania]

You're assuming Fahrenheit, there are lots of people with "computer IQs" in the Celsius scale. (20 is room temperature in Celsius)

LOL... I hope it's not that bad!



Michael

 

[TexasTexan]

I wonder if I can convert the lower bitrate mp3s into higher bitrate aac?

Ok that worked actually. iTunes converted a 32kbps mp3 into a 256 kbps aac. For people with low bitrate mp3s, Apple makes it easy to get around the 96kbps limit and possibly get matched.

And it seems match stalled on me yet again....

 

[milo]

Thanks to you guys for all the info. Has anyone figured out if it actually matches waveforms instead of just tags? Will it match a dummy file with fake metadata (not that I'd do this, just curious)?

I assume syncing is still disabled when match is turned on (meaning files still always come from the Apple server instead of local)?

I still need to figure out what I'm going to do with my library that's over 25k. Are things like podcasts and audiobooks included in that number? Does that number look at everything listed in the "Music" tab, whether the tag actually says music or something else? I'm still convinced they need options to exclude files but I wonder if I could get it to do that by changing the files I don't want to a different type.

Ok that worked actually. iTunes converted a 32kbps mp3 into a 256 kbps aac. For people with low bitrate mp3s, Apple makes it easy to get around the 96kbps limit and possibly get matched.

That's good news, and easy enough to work around. Looks like batch converting preserves ratings and play count (which really surprised me) but the downside is it doesn't put the new files in the same playlists as the old ones. I wonder if there's a way to work around that.

 

[TexasTexan]

Well, I would imagine that it uses wave form analysis of some kind. Looking at my outgoing traffic on my network card, it am not sending data samples out though. I can watch incoming traffic though since all my music is on a network hard drive, so I can't just see the traffic coming in from the internet. One simple test would be to take a matched track, copy it and then delete all the meta data. If it got matched then it would certainly being using a waveform analysis.

When you turn match on in an iDevice, it does say all music will be deleted. But I have seen one report that the music doesn't disappear until you sync your device again with iTunes (but take this with a grain of salt because I read a post from someone else)

 

[milo]

When you turn match on in an iDevice, it does say all music will be deleted. But I have seen one report that the music doesn't disappear until you sync your device again with iTunes (but take this with a grain of salt because I read a post from someone else)

I've heard that but it was previously reported that after match is enabled you can't tell it to sync again after that. So I assume smart playlists would require manually telling each to refresh and download the new songs as opposed to a single sync command. And instead of copying files from a local hard drive (wired or wireless) mobile devices always get songs from apple servers, using much more data and in many cases slower syncs.

 

[Tinmania]

OK I have confirmed that up-converting to a higher-bitrate for illegible tracks does in fact "work."

I quoted work because iTunes Match uploaded that Avril track and did not match it... and the track is available from iTunes store.

So basically I have that same quality I had, in all its 48kbps glory. Well actually worse because of another itineration of lossy compression.

So I am not sure why this wasn't matched... perhaps it is a different version of the song that was offered for free on Facebook (besides being low bitrate).

I might try it again with a different track unless someone else has one with which to try.



Michael

 

[bookemdano]

OK I have confirmed that up-converting to a higher-bitrate for illegible tracks does in fact "work."

I quoted work because iTunes Match uploaded that Avril track and did not match it... and the track is available from iTunes store.

So basically I have that same quality I had, in all its 48kbps glory. Well actually worse because of another itineration of lossy compression.

So I am not sure why this wasn't matched... perhaps it is a different version of the song that was offered for free on Facebook (besides being low bitrate).

It may just be that when a song is encoded at such a low bitrate (I mean 48kbps is REALLY, disgustingly low) it has already lost so much of the original waveform data that the matching algorithms can't recognize it with enough confidence to match it. You could be correct anyway in that maybe it's a different recording of the song, but I'm gathering that the unreliability of matching super-low bitrate songs is why Apple lists that as a restriction.

And Senseotech Do you still have the original files for those two "not eligible" tracks? If you do then test matching with those rather than the iTunes Match copies and see if you get a different result. Maybe you are right that the fact that they were downloaded from iTunes Match has nothing to do with it, but I wouldn't be surprised if it did. Maybe this is a new restriction that Apple is partially testing or something.

I'm also still interested in hearing from anyone who has tried to update an already matched library with new music (either from a CD you've ripped or an amazon mp3 album or whatever). Can you match just that one album without re-scanning your entire library? I'm sure a lot of people are interested in the answer to this.

Edit: TexasTexan I believe the two files that Senseotech is talking about were actually sourced from iTunes match--not only because he said they are 256kbps AAC files but if you go back to his other post he pasted a screenshot showing the file type as "Matched AAC Audio File". I believe that only shows for music downloaded via iTunes Match. That's why I thought it would be interesting to test again with the original music files to see if those are also classified as "not eligible".

And to whomever was wondering why iTunes Match is uploading cover art, even for matched songs. My guess is that it uploads the cover art if the original audio file has embedded artwork. iTunes itself doesn't embed artwork but other ripping/tagging apps do. And just as iTunes match preserves user-customized metadata, I'm guessing it also attempts to preserve user-embedded album art too. What I will be interested in seeing though is if it preserves the original resolution of the artwork or if it downrezzes it to something crappy. Speaking for myself, I always embed 500x500 artwork in all my audio files. So if iTunes Match will preserve that for me then I'll be a happy camper.

 

[TexasTexan]

Tinmania - I have some tracks I will try once I get matched. A couple dozen and I can try and see what they do. One interesting test would be to downgrade a matched track to the same 48kbps and then encode it back up. Of course I don't have the software to run that experiment.

Bookemdano - I have some tracks that purposely aren't in iTunes to try and see how they are added after the initial match (once I get matched, only 3,100 items to go, down from 9,900 yesterday) Ah, I didn't catch the Matched AAC Audio Track. I have seen that in the last beta when I delete a track to see what would happen when I re-downloaded it. It would be silly for them to exclude such a track from being matched to itself or definitely a bug.

I did try to add tracks to Match on a separate machine that aren't in my iTunes. It does know Matching is occurring on another machine and asks if I want to cancel or continue, which stops matching on the other computer.

----------

Ok, I looked at the tracks I had downloaded after they were matched in the last beta. They do indeed say Matched AAC audio file. However, all 10 of them were Matched this time around.

 

[distemp]

I'm having an issue on my 4S where many, many songs are not organized correctly. For example, if I look at my songs alphabetically, there are a lot of them that are under random letters and aren't placed where they should be.

 

[bookemdano]

I'm having an issue on my 4S where many, many songs are not organized correctly. For example, if I look at my songs alphabetically, there are a lot of them that are under random letters and aren't placed where they should be.

That's odd. Can you post a screenshot of what you're talking about, or provide some examples?

Do the songs show up that way in iTunes too or just on your iPhone?

 

[RTW]

SIMPLY PUT: iTunes Match cannot be using *tags* as a matching algorithm. It would be disastrous if it did. Somebody please confirm?

Can anyone report on how iTunes Match matches different masters/sources for similar files? I mean, will it match my 1992 version of U2's Achtung Baby to the 2011 remastered version? It shouldn't. And I hope it doesn't. But a lot of people here seem to feel that a track is a track, regardless of the source. I hope Apple doesn't take the same stance.

 

[distemp]

That's odd. Can you post a screenshot of what you're talking about, or provide some examples?

Do the songs show up that way in iTunes too or just on your iPhone?

All is well in iTunes, it's just the Music App on my phone. I'll try to upload a screenshot to...somewhere.

 

[distemp]

 

[TexasTexan]

Can anyone report on how iTunes Match matches different masters/sources for similar files? I mean, will it match my 1992 version of U2's Achtung Baby to the 2011 remastered version? It shouldn't. And I hope it doesn't. But a lot of people here seem to feel that a track is a track, regardless of the source. I hope Apple doesn't take the same stance.

I did read that somewhere that iTunes match might match the same song from a different album. Now to me, remastered is different. Should be to apple. I am thinking same song but matched to the wrong album would be like a song from one album being on a greatest hits cd, same exact track just different place. Remastered is not the same exact track.

I am wondering if they use the meta data as a starting point and then waveform as verification. If they did that then if your meta data was for the remastered version, Apple checks your waveform against that one. Now, if your track has no meta data, it might match what ever it finds first that is close enough, which might be the original track. Just a theory....

 

[Tinmania]

SIMPLY PUT: iTunes Match cannot be using *tags* as a matching algorithm. It would be disastrous if it did. Somebody please confirm?

Can anyone report on how iTunes Match matches different masters/sources for similar files? I mean, will it match my 1992 version of U2's Achtung Baby to the 2011 remastered version? It shouldn't. And I hope it doesn't. But a lot of people here seem to feel that a track is a track, regardless of the source. I hope Apple doesn't take the same stance.

Well if the track is truly different it "should" not change it. But I did hear one case of it taking an explicit track and matching it to the non-explicate version.

Now if the same exact song is included in multiple albums (main, greatest hits, etc.) It seems to go with the first released version. But I have not checked to see if included metadata overrides that.



Michael

----------

It may just be that when a song is encoded at such a low bitrate (I mean 48kbps is REALLY, disgustingly low) it has already lost so much of the original waveform data that the matching algorithms can't recognize it with enough confidence to match it. You could be correct anyway in that maybe it's a different recording of the song, but I'm gathering that the unreliability of matching super-low bitrate songs is why Apple lists that as a restriction.

Considering how well Shazam and Sound Hound do with recognizing songs I can't imagine this was the reason for not allowing low-bitrate tracks. I suspect it was more of a licensing issue than anything else, but that is easily tested by trying it with a known-to-match track at a lower bitrate.



Michael

 

[bookemdano]

SIMPLY PUT: iTunes Match cannot be using *tags* as a matching algorithm. It would be disastrous if it did. Somebody please confirm?

Can anyone report on how iTunes Match matches different masters/sources for similar files? I mean, will it match my 1992 version of U2's Achtung Baby to the 2011 remastered version? It shouldn't. And I hope it doesn't. But a lot of people here seem to feel that a track is a track, regardless of the source. I hope Apple doesn't take the same stance.

I haven't tested it myself so I can't answer your second question but based on other posts in this thread I can confirm 100% that tags are not used to match audio files (at least not primarily--perhaps they are given some weight in resolving conflicts--where the same track appears on multiple albums). My guess (as in I have no proof of this) is that is goes something like this:

1. Perform waveform analysis
2. If waveform matches only one track in the store, then move on to the next one.
3. If waveform matches several different tracks in the store, then look at track metadata to help determine which one is correct (if you think about it, the metadata is all that matters in that case anyway--if the song itself is identical then at that point just the metadata is needed to classify it as part of a given album).

I'd bet the waveform analysis they perform is sophisticated enough to detect differences between various remixes and remasters. The precision of the algorithm is why they require your original audio files to have a minimum bitrate in order to match.

 

[distemp]

Well if the track is truly different it "should" not change it. But I did hear one case of it taking an explicit track and matching it to the non-explicate version.

Now if the same exact song is included in multiple albums (main, greatest hits, etc.) It seems to go with the first released version. But I have not checked to see if included metadata overrides that.



Michael

I had it match an incorrect version of a song that I had, very stupidly, already deleted the original of after I downloaded the match. We're not talking going from explicit to clean, it was more like from an original to a random newer recording with slightly different music.

 

[bookemdano]

Considering how well Shazam and Sound Hound do with recognizing songs I can't imagine this was the reason for not allowing low-bitrate tracks. I suspect it was more of a licensing issue than anything else, but that is easily tested by trying it with a known-to-match track at a lower bitrate.

Yes but Shazam and SoundHound do not need the precision that iTunes Match does. They don't need to be able to differentiate between album and live versions, remasters, etc. iTunes Match does. And it's those minute differences in the waveform that help it tell the difference.

I'm not saying that in all cases a very low bitrate file can't be properly differentiated, but Apple probably figured that it was unreliable enough to make it a rule. I doubt it has anything whatsoever to do with licensing issues. The vast majority of pirated music is 128kbps or above.

Edit: and someone on the previous page of this thread already tested transcoding the low-bitrate file to a higher bitrate. iTunes Match then uploaded the file rather than match it.

 

[Senseotech]

It may just be that when a song is encoded at such a low bitrate (I mean 48kbps is REALLY, disgustingly low) it has already lost so much of the original waveform data that the matching algorithms can't recognize it with enough confidence to match it. You could be correct anyway in that maybe it's a different recording of the song, but I'm gathering that the unreliability of matching super-low bitrate songs is why Apple lists that as a restriction.

And Senseotech Do you still have the original files for those two "not eligible" tracks? If you do then test matching with those rather than the iTunes Match copies and see if you get a different result. Maybe you are right that the fact that they were downloaded from iTunes Match has nothing to do with it, but I wouldn't be surprised if it did. Maybe this is a new restriction that Apple is partially testing or something.

I'm also still interested in hearing from anyone who has tried to update an already matched library with new music (either from a CD you've ripped or an amazon mp3 album or whatever). Can you match just that one album without re-scanning your entire library? I'm sure a lot of people are interested in the answer to this.

Edit: TexasTexan I believe the two files that Senseotech is talking about were actually sourced from iTunes match--not only because he said they are 256kbps AAC files but if you go back to his other post he pasted a screenshot showing the file type as "Matched AAC Audio File". I believe that only shows for music downloaded via iTunes Match. That's why I thought it would be interesting to test again with the original music files to see if those are also classified as "not eligible".

And to whomever was wondering why iTunes Match is uploading cover art, even for matched songs. My guess is that it uploads the cover art if the original audio file has embedded artwork. iTunes itself doesn't embed artwork but other ripping/tagging apps do. And just as iTunes match preserves user-customized metadata, I'm guessing it also attempts to preserve user-embedded album art too. What I will be interested in seeing though is if it preserves the original resolution of the artwork or if it downrezzes it to something crappy. Speaking for myself, I always embed 500x500 artwork in all my audio files. So if iTunes Match will preserve that for me then I'll be a happy camper.

As I said, the other 300+ songs I had from previous betas as "Matched AAC files" were matched again, as it should be. Just these two tracks were not matched or uploaded, while the exact same track on a different album got match treatment.

EDIT: My personal opinion on this specific track, the low-quality one that was then unconverted, is that if it was a free track from somewhere, perhaps it was slightly different, either a little longer, a little shorter, or the content was just "off" enough to not do a waveform match, thus no matter what the quality, it would've been an upload instead of a match.

 

[Tinmania]

Yes but Shazam and SoundHound do not need the precision that iTunes Match does. They don't need to be able to differentiate between album and live versions, remasters, etc. iTunes Match does. And it's those minute differences in the waveform that help it tell the difference.

I'm not saying that in all cases a very low bitrate file can't be properly differentiated, but Apple probably figured that it was unreliable enough to make it a rule. I doubt it has anything whatsoever to do with licensing issues. The vast majority of pirated music is 128kbps or above.

Edit: and someone on the previous page of this thread already tested transcoding the low-bitrate file to a higher bitrate. iTunes Match then uploaded the file rather than match it.

That was me that did that, but it was possibly an unusual song offered for free on Facebook.

As for bringing up Shazam, I didn't mean they analyze as much as Match would need to. Only that they recognize tracks in DEPLORABLE conditions and get it done. We are talking a crappy radio station in a noisy car and yet it does it--probably at far less than 96kbps too. Also, Match uses the same wave form analysis as iTunes TuneUP and it has no such bitrate limitation. But it does not matter as that is the way Match works so deal with it we must.




Michael