Jump to content

Serious Beat Mapping bug?


FlowerPower

Recommended Posts

Can anyone confirm this? I sort of need urgent assistance with this one...

 

Beat mapping MIDI events should reclock + insert tempo changes to maintain the original tempo of the material. If beat mapping a MIDI note in the middle of a song, earlier MIDI notes should get a new bar/beat position (if things are done right). This worked fine in Logic 8 and earlier versions of OS X and Pro Kit.

 

Here's a serious problem I have in 9.1.3 and 10.6.6 (but not in Logic 8.02).

 

Record something simple, not to a click, eg. 5-6 simple chords with a few fill in notes, to a relatively stead beat (but not click).

 

Beat map the material loosely (but not all the bars), to get the event/grid relations right. If I beat map, say, the first and third chord to get things right, and later find out that I also want/need to beat map a note in the second chord, the event/grid relationship if the notes in the first chord are messed up, at least if they don't start at the beginning of that region. THey even move to positions before the regions left edge.

 

Again, this used to work fine, so something has changed. I just don't know what, or if there's any workarounds for this.

Link to comment
Share on other sites

I know there's a "protect MIDI" function, but I've never trusted it to work. So my first suggestion would be to SMPTE-lock (everything) and then do your beat mapping. Unlock everything when you're done.

 

Thanks.

 

I think protect MIDI is only meant to use if you want to reclock audio but not MIDI - like a real SMPTE lock for all MIDI events?

 

Locking to SMPTE may be a workaround - at least if you only work with one region, but that wasn't necessary earlier. Logic sort of locked everything to time position (during the beat map process) - which is what beat map/reclock is about anyway: to let the material stay where it was (in terms of absolute time/heard result), but change the grid. And since it's all about keeping the events where they are (heard), locking them to that position shouldn't be - and hasn't been - needed if things are done right; not in situations like this.

 

I have used BM many times without having these problems, including in L9-versions. But when I retried eg. 9.02 now, that version behaves buggy as well, while 8.02 - created before the current OS was created - works fine with the current OS.

 

As a side effect of the new behavior, I'm also able to - to some degree - drag the left corner of a region to a position after the first MIDI notes in that region, which shouldn't be possible. Something mysterious is happening.

 

There's also a bug while beat mapping within the piano roll: the yellow line created by the beat mapping process doesn't disappear after an Undo - but this seems to be a graphical bug. After an edit, the beams representing notes in the BM track don't always update immediately either (in the Piano Roll beat map track).

 

If you look at the two attached images, before and after beat mapping, you'll see that two of the three notes in the first chord have changed their position after the beat mapping - even if they all start at the same position.

 

The tempo event at position 5 2 1 1 shouldn't be able to cause this, so it must be the beat mapping/reclock process itself that's broken (or how it related to the OS etc). It could also be my Mac, but I sent the file to someone who confirms that this happens at his place as well. Very weird.

966357248_AfterBeatMap.png.12d846e7a7f7df822c98b283834c4925.png

834801497_PreBeatMap.png.c861de07a10487fbfb5cec39b4956590.png

Link to comment
Share on other sites

Wow, very strange indeed.

 

FWIW, I've never been able to use beat mapping on MIDI regions successfully without SMPTE-locking them first. If I don't, the very first new tempo event generated from beat mapping alters the timing of the remainder of the part(s). So I'm not sure how it's even possible to do beat mapping without first SMPTE-locking a region (or everything in the arrangement, for that matter).

 

Recently I had the opportunity to try this out on a 9.0.2 system running on a MacIntel and found exactly the same behavior to be true.

 

Sorry to see that you're having such problems.

Link to comment
Share on other sites

I am probably being dense here, but isn't the whole point of beat mapping to create what we old dogs used to call a "variable click track" to manipulate MIDI events so that we could play other parts along with a part that was not quantized to a grid? Wouldn't that by definition need to move MIDI events bar/beat position?
Link to comment
Share on other sites

I am probably being dense here

 

Sure. :D

(But not really...)

 

 

 

If you only use this variation of Beat Mapping (along with "Detect")...

http://prohelp.apple.com/logicpro_help-r01/English/en/logicpro/usermanual/Art/S09/S0979_BMR_BeatsFromRegion.png

... you are somehow right.

 

But Beat Mapping replaced the old Reclock function in Logic, and is IMHO 100 times better (when it works, which it usually have done), but it doesn't necessarily have to do with click tracks.

 

Audio Beat Mapping still works. Regarding MIDI Beat Mapping (for those who aren't familiar with this feature): If you play something on a MIDI keyboard that sounds the way it should, but doesn't follow a grid, you can beat map the MIDI region to make the notes look right in Score - without being quantized or altered in any way. Often that's all you want, including when you compose/arr. additional tracks to that track,

 

Another scenario: the regions sounds pretty good, but you want to quantize some sections. After a Beat Map, you can quantize all the stuff, it will still have that rubato timing (if that's what it had), but you can straighten up the sloppy notes with Quantize.

 

Or, you want to add more tracks and generate a usable click, as you mentioned. That's at least what people often do when they record a MIDI click track manually and use Beats From Region (which I've never done).

 

Or: the region is so 'alive', time-wise, that it can't be quantized - but after a Beat Map, not only will everything look right... but if you remove all the tempo events generated by the MIDI Beat Mapping process, it will look right *and* have static time - without the need for quantizing anything.

 

You can also Beat Map to Markers and to Scene Markers in movies.

 

Wouldn't that by definition need to move MIDI events bar/beat position?

That's quantizing, isn't it? Beat Mapping is somehow the opposite: one asks Logic to reclock the project so that the bar lines will follow the notes. Tempo changes are inserted to make sure that the result will sound as it did before the quantizing (unless you want something else).

 

It may look like the notes are moved (and maybe, technically, they are maybe even moved twice), but the process is very different from quantizing - at least from a users point of view.

 

I guess that essentially, Logic calculates how many ticks it must add or subtract for the note to end up where you want it to; then calculates how off it will sound (according to the original timing), and finaclly calculates and inserts a tempo change to compensate for the new clock position.

 

Ignore the last part as it's pure speculation. :) The bug I've encountered in Logic still shouldn't be there even if the only purpose of reclocking was to generate a good, floating click track, because Logic moves notes that already has been fixed (reclocked) when reclocking following notes (and more).

Link to comment
Share on other sites

I am probably being dense here

 

Sure. :D

(But not really...)

 

 

 

If you only use this variation of Beat Mapping (along with "Detect")...

http://prohelp.apple.com/logicpro_help-r01/English/en/logicpro/usermanual/Art/S09/S0979_BMR_BeatsFromRegion.png

... you are somehow right.

 

But Beat Mapping replaced the old Reclock function in Logic, and is IMHO 100 times better (when it works, which it usually have done), but it doesn't necessarily have to do with click tracks.

 

Audio Beat Mapping still works. Regarding MIDI Beat Mapping (for those who aren't familiar with this feature): If you play something on a MIDI keyboard that sounds the way it should, but doesn't follow a grid, you can beat map the MIDI region to make the notes look right in Score - without being quantized or altered in any way. Often that's all you want, including when you compose/arr. additional tracks to that track,

 

Another scenario: the regions sounds pretty good, but you want to quantize some sections. After a Beat Map, you can quantize all the stuff, it will still have that rubato timing (if that's what it had), but you can straighten up the sloppy notes with Quantize.

 

Or, you want to add more tracks and generate a usable click, as you mentioned. That's at least what people often do when they record a MIDI click track manually and use Beats From Region (which I've never done).

 

Or: the region is so 'alive', time-wise, that it can't be quantized - but after a Beat Map, not only will everything look right... but if you remove all the tempo events generated by the MIDI Beat Mapping process, it will look right *and* have static time - without the need for quantizing anything.

 

You can also Beat Map to Markers and to Scene Markers in movies.

 

Wouldn't that by definition need to move MIDI events bar/beat position?

That's quantizing, isn't it? Beat Mapping is somehow the opposite: one asks Logic to reclock the project so that the bar lines will follow the notes. Tempo changes are inserted to make sure that the result will sound as it did before the quantizing (unless you want something else).

 

It may look like the notes are moved (and maybe, technically, they are maybe even moved twice), but the process is very different from quantizing - at least from a users point of view.

 

I guess that essentially, Logic calculates how many ticks it must add or subtract for the note to end up where you want it to; then calculates how off it will sound (according to the original timing), and finaclly calculates and inserts a tempo change to compensate for the new clock position.

 

Ignore the last part as it's pure speculation. :) The bug I've encountered in Logic still shouldn't be there even if the only purpose of reclocking was to generate a good, floating click track, because Logic moves notes that already has been fixed (reclocked) when reclocking following notes (and more).

 

Of course, but my point is how it look in a score i.e.s in terms of relationship is changed, and obviously MIDI by definition as it is simply a set of instructions, responds to tempo , unless you tell it specifically not to, so by beat mapping you are setting tempi so that it sounds as you want and yet generates a click that other parts can be played to and my guess is that is what it is most frequently used for.

 

I have found it to work quite well when I use it, but it is painstaking work.

Link to comment
Share on other sites

Yes, you are setting a tempo, but if you only would insert tempo changes - and not reclock at the same time - the notes of course wouldn't match the grid.

 

This worked fine in Logic 8, and still does (but not always) situations in Logic 9.

 

Re. painstaking - imagine how complex this process would have been in the old days:

 

Link to comment
Share on other sites

Yes, you are setting a tempo, but if you only would insert tempo changes - and not reclock at the same time - the notes of course wouldn't match the grid.

 

This worked fine in Logic 8, and still does (but not always) situations in Logic 9.

 

Re. painstaking - imagine how complex this process would have been in the old days:

 

 

Yes, I remember it well.

Link to comment
Share on other sites

Archived

This topic is now archived and is closed to further replies.

×
×
  • Create New...