I guess it's possible the music is recorded (which then becomes the OST) and then the rerecording mixers manipulate it during the mix to better fit the on-screen action

It also depends on whether the score is a "complete" one. So far I've synced two movies to soundtracks. Armageddon complete and Last Jedi in one or two scenes. In both cases the music on the OST is sometimes cut differently to fit the image better. Sometimes skillfully, sometimes less so. For example in the Last Jedi prologue with the space ships arriving, there is a part of the OST with the drums that is looped, where it isn't in the OST. It actually sounds a bit "off", but I had concluded it's supposed to be that way. Apparently not. Was hacked together by the editor of the movie.

The Armageddon one is more complete, but still is sometimes cut differently in the movie.

To conclude, OSTs aren't really meant to be 1:1 syncable to movies. They are really more of a thing done purely for fans to relive some of the moments in a purely musical way, also often leaving out a lot of parts. In the movie they are sometimes/often cut differently to match the on-screen action, as zoidberg says, even in parts that adhere to the OST relatively well. This is particularly true for Star Wars scores, which are missing a lot of themes typically.

(2018-04-14, 04:32 PM)spoRv Wrote: EDIT: and, why, out of curiosity, the CD soundtrack, once aligned, is perfectly in sync with a 23.976fps source?

This is something about which I've often wondered, and I have yet to find a clear answer. (It came up when I was discussing audio from a print with another forum member.) You are right that the drift between 23.976fps and 24fps soon becomes significant.

If you want to find out about the 24fps vs 23.976fps issue, you could make an experiment for the movie of your choice. Get yourself an audio sequencing software, then find a VST plugin for sample-accurate delay measuring and syncing (these exist! and they work.), then measure both at the beginning and end of the song (ideally one that doesn't have any cuts in the movie of course!). See if the delay is identical both in beginning and end. If it is, it's in sync. If not, there is a speed mismatch. Then you could try resampling the audio to match the other framerate and try again and see if it fits better.

The OST I'm working on (almost finished) is Waterworld; apart extra/modified ones, there are 35 tracks; all of them, except one (and a half), are in the film, almost in the same identical form - two or three are longer or shorter; the end credits are similar, but a different version, that I don't like, and it will not be included; I included the missing one in a place where I feel it belongs, while I have not included the half one, because the film's is better IMHO.

So, all in all an almost complete 1:1 OST - let's say it has a very good lossy compression!

Well like minds I guess...

I’m on my third isolated soundtrack, in this case it is Blade Runner 2049. So I’ll use that as the example and kind of reiterate some of the points everyone has been talking about.

2049 works pretty well with the track matching speed-wise. I have yet to have any 23.976 problems. I doubt a particular music piece lasts long enough to drop significant sync except maybe the end titles The only challenge is duplicating the film specific mix points.

A good example is on the OST the second track, Sappers Tree plays out for another minute or two then on film. In the film the heavy bass/drum note from the third track, Flight to LA kicks in and Sappers Tree fades out. So I have to recreate that mix and many other to not only be faithful to the film but to match the on screen image.

OSTs are usually the original tracks recorded for the film but since they preceed the sound mixing they can get altered later greatly. That or the composer wanted to added a little more. Hell a lot of soundtracks don’t contain all the music composed for the film.

A counter point is the original Blade Runner, which like Alien has its soundtrack cut to shreads. Pieces of single tracks are all over the film. I gave up on doing the one. Without production matieral it was impossible.

Of note are the volume issues since most soundtracks are brickwalled and scream the music when compared to the film

Also casting my vote. I found silence works best in between tracks. I started trying to use effects from the sides and rears and found that any mixer worth he salt has added echo effects or off screen dialogue. Once you have dialogue on the isolated score it ruins the effect.

(2018-04-14, 04:32 PM)spoRv Wrote: ...what's about blank parts? Should I replace them with the movie track (eventually with needed fade ins/outs)? Or with movie track without dialogs? Or should I leave them blank, silenced?

Andrea, doesn't voting in your own polls kind of defeat the point a bit?    

Well, it's like at the elections... does the President vote, too, doesn't he?

About Waterworld: as for now, I just NOT included one movie part, where Deacon talks to Enola, as voices spills over both front channels, and read ones are fundamentally empty.

Now, I discovered that there are few tracks (at least, according to their names) not present in the one which I used - that I thought was the most complete... oh well, let's check them out, and see if I should add them or not!

With my Superman isolated scores, I left silence between tracks. There are a few tracks that had been edited down during the post production process, so I had to chop up the full cues to match what they did in the finished movie. Quite tricky in a few places with dialogue and whatnot to try and spot the edit points.

(2018-04-14, 10:10 PM)PDB Wrote: 2049 works pretty well with the track matching speed-wise. I have yet to have any 23.976 problems. I doubt a particular music piece lasts long enough to drop significant sync except maybe the end titles The only challenge is duplicating the film specific mix points.

I think the reason why you were not having any trouble with this is because the film’s distributor had decided to release the film, both the theatre releases and home video releases (streaming and physical media), at a speed of 23.976fps. So, the music was scored-written and recorded-for that speed.

During the days of showing celluloid film in theatres, all the sound elements—music, vocals, sound effects, etc.—were sync’d to the film’s speed of 24fps. When time came to release these films for home video and TV broadcasts, they had to do the work in prepping them for either media—whether they did it in-house or hire a third party to do the work. One of the labors was to adjust the speed of the audio for home viewing exhibition--speed it up for PAL (25fps), or slow it down for NTSC (29.97fps)

Now that today’s films are assembled and shown in the digital media, the distributor can decide how many frames per second their movies can be shown. I am thinking that in the cases of ‘Blade Runner 2049’and other movies, the distributor wanted them to be displayed at 23.976fps for the theatre release, so, that they can save time on having to make adjustments for home video releases like change the audio speed, since Blu Ray discs are at a compliance of 23.976fps. By keeping the said fps, the distributor doesn’t have to worry about the complications that come-up during this said process
• Audio distortion when extending the duration of the audio during conversion from 24fps to 29.97fps or even 23.975fps
• Pitch changes when speeding-up the audio for PAL

Now that many distributors are heading towards streaming their media inventory instead of replicating physical discs, there’s a possibility that they may do away with 23.976fps.