Cubase SX includes many powerful commands for building tempo maps when writing to picture. Here you can see the Time Warp tool being used to create a tempo map based on hitpoints in the video that have been identified by Markers on a Marker track. Notice how the Ruler on the Project window turns dark red when the Time Warp tool is active, and how the tempo changes are illustrated with triangles. The Tempo Editor shows a more graphical overview of the Tempo Events.
This month we take a look at building tempo maps for writing to picture in Cubase, using Markers, Time Warping and the Process Tempo command.
Last month we started to investigate working with video in Cubase, looking specifically at the pros and cons of having your video running inside or outside of Cubase, and how to use the built-in video playback features. In this month's article we're going to take a look at the process of actually building tempo maps in Cubase, and you might want to follow the examples discussed with an empty Project on your own system. You won't need any additional video files or musical content for these examples. If you're interested in running Cubase with an external video machine, check out the 'Slave To The Cubase ' box for more information.
Project Time
One thing to bear in mind if you're running video in Cubase is that the timecode of the video always needs to be locked to the timecode of the Project. Last month we looked at how to set the Project start time (in the Project Setup window) and aligning the Video Event to be in sync with the Project; but quite often this will still need further adjusting, which is to say you probably don't always want the beginning of the video to be the beginning of the Project. For example, say the 24-frame video starts at 01:00:00:00, your music starts at 01:00:05:00, and you want the first bar of music to be bar three at 120bpm. It's a good idea to leave a couple of empty bars at the start of your Project in case you need to have an up-beat or make changes later on.
Keeping the video where it is, you could achieve this by setting the tempo to 96bpm at the beginning of the Project (bar one) and putting a tempo change to 120bpm at bar three, but this is an awkward solution. It would make it harder to use up-beats, and if you later got real musicians to play your music against a click track, you'd have to manually cut in a click at the right tempo (120bpm) so they had a proper count-in.
To help in these situations, Cubase has a neat command called Set Timecode at Cursor (in the Project menu), which does exactly what it says. To set bar three to be 01:00:05:00 you would set your Project Cursor to bar three, select Set Timecode at Cursor, enter the timecode and click OK. Cubase will automatically work out the offset that is required to make the timecode you entered hit the cursor's bar and beat position, so in this case, bar three will now be 01:00:05:00, and you don't have to worry about tempo changes.
When you change the start time of the Project, either in the Project Setup window or with the Set Timecode at Cursor command, Cubase will prompt you to see if you want any existing objects to move so they stay at the same timecode position. Most of the time you'll want to say 'No', when working with bars and beats. And spot the missing word...
If you already have content in your Project, before the Set Timecode operation is complete Cubase will prompt you: 'You have modified the timecode offset. Do you want [to] keep the Project content at its timecode positions?' Aside from the missing word, this seemingly confusing question is actually fairly straightforward. Most of the time you'll want to say 'No' to this question: if you have some MIDI and audio Parts on the Project window already at bar three, you probably want to keep them at bar three. Clicking 'Yes' would move your existing objects so their timecode position was preserved, which would place them at musically irrelevant locations.
If you're using Cubase with an external video player, you have nothing else to worry about. However, if you're using the built-in video player, you'll need to make sure you readjust the position of the Video Event so that it's in sync with the Project's timecode again. In theory, if the Video Event is the only Event in the Project (and it's already correctly lined up before the timecode adjustment), you could answer 'Yes' to the question. However, if the new timecode is later than the old time, this moves the start point of the Event behind the start of the Project, and Cubase's video player doesn't always seem happy about this. So the best option is probably to readjust the start of the Video Event manually, cropping either the start or the end positions as you would for any other type of Event on the Project window.
Hit Me Baby, One More Time
Once you've got the initial tempo set and the Project start time sorted out, a common task is to identify various hitpoints in the video that you want to tie in with something musically meaningful. One useful technique is to create a Marker track in your Project and add Markers to represent the hitpoints in the video. To create a Marker track, select Project / Add Track / Marker, and you might like to enable Cubase's Divide Track List function by clicking the appropriate button (which looks like an empty rectangular box) at the very top of the Track List, just where the Track List and the Ruler intersect. In this mode, the Event Display and Track List are split into two areas, and by default the Marker track is automatically moved into the upper area. The two areas of the Track List can be vertically scrolled independently of each other (and you can drag the dividing line between the two areas to resize them as you wish) and this makes it possible to keep the Marker track at the top of the Project window, no matter what tracks are visible in the lower part of the Track List.
Creating a Marker track is a helpful way to identify points in the video that you want to align to musically relevant locations. You can then use the Time Warp tool, as illustrated here, to create appropriate tempo changes when dragging bars or beats onto Markers.
Let's say you have a hitpoint at 01:00:30:18. To create a Marker at this position, first set the Project Cursor to this timecode location. As mentioned last month, when you're working with picture you'll probably want to have Bars+Beats set as your Primary Time Display and Timecode as your Secondary Time Display. So to set the Project Cursor to a timecode location, click in the Secondary Display area on the Transport Panel and type in the required timecode value. After this, you can insert a Marker by clicking the Add Marker button on the Marker track itself, or by pressing Insert on Windows-based systems (no default Key Command is assigned on the Mac version), and the Marker is added at the Project Cursor's position.
You'll probably want to give the Marker a name to indicate what's going on at the time of that hitpoint, such as 'Man types in Marker name in Cubase ', and to do this, first make sure you have Show Marker Names enabled in the Event Display-Markers page of the Preferences window. When a Marker is selected on the Project window, its Name ID and Start time are shown in the Event Infoline, and you can enter a name by clicking underneath the name field, typing the name and pressing Return. Marker data can also be edited in the Inspector, so long as the Marker track is selected, and also in the Marker window, which you can open by selecting Project / Markers or pressing Ctrl/Apple+M. In these latter two views, the Marker name is listed in the Description field.
The last thing you might want to consider when using the Marker track for hitpoints is to switch its timebase from the default Musical option to Linear, which you can do by clicking the illuminated note button on the Marker track so it changes to a non-illuminated clock. Musical timebase is the setting to which all Cubase tracks default, with the exception of the Video track, and this means that Events on a track are stored in relation to their music position in bars and beats. Therefore, if you have an event at bar three and you change the tempo, the event still occurs at bar three, but the exact time at which it occurs in minutes and seconds will have changed depending on whether the new tempo is faster or slower. Linear time, by contrast, stores Events in relation to their absolute position in time, regardless of bars, beats and tempo. If the Marker track was left in Musical time, the Markers representing the hitpoints would drift depending on the tempo, which is absolutely not what you want. Enabling Linear time on the Marker track prevents this.
Doing The Time Warp
Once you've created some hitpoints, the next step is to come up with a musical structure to incorporate these hitpoints in a way that makes sense. Cubase SX2 introduced the Time Warp tool, allowing you drag bars and beats on to specific linear time positions, and, as you can imagine, combing the Time Warp tool with the Markers is a pretty handy way of building a tempo map in Cubase. As a simple example, the Marker we created in the previous section at 01:00:30:18 happens to fall at beat 15.4.3.0 in the musical timebase. Since it's almost hitting bar 16, you might want to simply move bar 16 so 01:00:30:18 hits this musical location.
To do this, select the Time Warp tool, make sure Snap mode is enabled and set Snap to Events. Now, drag the first beat of bar 16 in the Marker track onto the Marker, and because Snap is set to Events, you'll notice that the bar line you're dragging automatically locks to the Marker as the mouse pointer gets close. And, as an aside, if you don't drag within the Marker track area, the bar line won't snap to the Marker.
Here you can see tempo changes in the example described in the main text before processing with the Process Tempo operation.The Time Warp tool works by automatically adjusting the last tempo change in the Project so the bar or beat you're dragging will hit the required position. In the current example, the tempo at the start of the Project is adjusted because we don't have any other tempo changes in the Project right now, which means the tempo at the start of the Project will now be 121.008bpm. This means that bar three now hits 01:00:04:23 instead of 01:00:05:00; being one frame out might not matter too much, so you might be happy to live with it.
However, what if being one frame out did matter? One possibility to consider is to put bar three back to its original location and put a subtle tempo change halfway through, maybe at bar nine, instead. Bear in mind that normally you could choose a location that made sense musically, instead of an arbitrary position, but this is just intended to illustrate the process. Start by undoing the previous operation where bar 16 was dragged to 01:00:30:18, so that the tempo at the start of the Project is once again 120bpm and bar three hits 01:00:05:00. Next create a Tempo Event at bar three by Shift-clicking bar three in the Event Display (not in the Ruler) with the Time Warp Tool. This, in effect, locks bar three to 01:00:05:00, as it's impossible for the Time Warp tool to affect the tempo behind bar three at this point.
Next create another Tempo Event at bar nine; again, this effectively locks all the bars behind bar nine from being affected by tempo changes after bar nine. Now, you can drag bar 16 to the Marker again at 01:00:30:18 and the last tempo change will be adjusted — in this case the tempo change at bar nine — so that bar 16 hits the required timecode, leaving all the bars before bar nine (including the all-important bar three) alone.
And that's basically all there is to using the Time Warp tool to build tempo maps. One nice thing about the Time Warp tool is that as you hover the mouse around the Event Display, an info box is drawn detailing the current musical time and timecode position of the mouse. This is a quick way to see what the timecode value of a bar or beat is without moving the Project Cursor. Another point is that you'll notice that when the Time Warp tool is selected, Cubase draws the locations of tempo changes in the Ruler, indicated by small triangles. In the same way that Shift-clicking in the Event Display creates a new tempo change, Shift-clicking a Tempo Event in the Ruler deletes it.
Process Tempo
The Time Warp tool is truly a great aid for building tempo maps, but it has a couple of limitations: because only the last tempo change is adjusted when you drag a bar, it means you can only affect one tempo change at a time, and it has to be an immediate (what Cubase would term a Jump Event) change. What if you wanted to adjust several tempo changes simultaneously so that you could affect a sequence of Tempo Events proportionally to hit a cut in the picture? For this, you'll need the Process Tempo command.
Process Tempo is a powerful command to process tempo changes within a given range in order to hit a specific timecode position with a musical location.
Forgetting the previously discussed examples, imagine you have a 24fps Project starting at 01:00:00:00 with an initial tempo of 120bpm. At bar five there's a Jump Tempo Event to 110bpm, and at bars 13 and 21 there are two Ramp Tempo Events to 124 and 115 bpm respectively (see the screen on the previous page). Bar 25 currently hits 01:00:48:20, but you just got a new version of the picture and you need to make the music slower as the picture is now a bit longer and bar 25 now needs to hit 01:00:53:02 instead.
To do this, open the Tempo Editor and click the Process Tempo button on the Tempo Editor's toolbar. If you don't see the button, right-click an empty space of the Tempo Editor's toolbar and make sure Process Tempo is selected in the list of elements to be displayed on the toolbar.
In the Process Tempo window, make sure Time Display Format is set to Timecode. Next, set the range of the Project where tempo changes should be processed in the Process Range section. If you select a group of Tempo Events in the Tempo Editor before opening the Process Tempo window, Cubase will automatically set the Process Range according to the selection. However, in this case, set the Start to bar one (1.1.1.0) and the End to bar 25 (25.1.1.0) — the End value should always be the musical location you want to hit with a given timecode position. Next, set the End value in New Range to the timecode value you want to hit, in this case 01:00:53:02, click Process, and then click Close to close the window.
You'll notice that Cubase scales the tempo changes; and because there was no Tempo Event at bar 25 (the bar at the end of the range), a tempo change will be automatically inserted to preserve the original tempo at that point. However, if you want to continue with the same tempo during bar 25 as before, simply delete the newly inserted tempo change as this will have no effect on bar 25 itself hitting the correct tempo position. If you check bar 25, you'll see it now hits 01:00:53:02 as we intended.
And that's all there is to it! Having read both this and last month's article, I hope you now have a better understanding not just of how to use Cubase's video-related features, but also how to decide which ones suit the task at hand. Whether using video inside or outside of Cubase, and whether you use the Time Warp tool or Process Tempo (or both) for building your tempo maps, all that remains is for you to actually write the cue and sell it to a director! And, unfortunately, there isn't a plug-in that can do that for you just yet.
Published December 2005
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