Friday, February 02, 2007

Pete's guide to home video V - Editing your movie

Editing your movie

With all your video and audio files on your hard disk, you're ready to start putting it all together to create your movie. In this article I'm going to describe the sequence of steps I use to do this. It's useful to develop a general plan like this - it gives you something to work to, where you don't get stuck wondering what to do next, and can also give you a useful sense of progress as you go along.

Reviewing & trimming

The first thing I do is to review each shot using the NLE. As I play through each file I do a couple of things:

First, I jot down a note to say whether I even want to use the shot in the finished movie - in some cases, depending on how bad my camerawork was, more than half of the shots may not be useful.

Secondly I do my first pass of trimming - marking the start and end points of the useful footage (the NLE I use lets me save the marked sections as "subclips") so as to exclude lead-in, lead-out and other sections that I'm not interested in using. If I know in advance that I'm going to need some "freeze frame" effects, this is usually where I'll capture the frames I need.

As I'm going along I usually also make a note of the order I want the clips to appear in the final movie. This isn't set in concrete - more often than not I'll change the order a bit at a later stage, but by getting a feel for this at the review stage gives me something to work to in the next step, and that saves time. I can also mark up my B-reel footage.

Reviewing is possibly the most time consuming step, particularly if there are a lot of files to go through. Once I'm done reviewing, I can get to the fun part.

Laying down the main video track

This step is made much simpler by the notes I made in the previous step, about the order of the clips. It's just a case of dragging and dropping each clip onto the timeline in sequence. At this time I may change some of my decisions about the order of the clips (and the order may change again later, too).

This is where I make most of the decisions on how to transition between shots. In many cases I want a hard cut, straight from one shot into the next, but there will also be places where I want to cross-fade, or I may want to fade the end of one shot to black, hold it for a second, then fade the next shot in.

I mentioned in an earlier post that on occasion you may not have enough time between the end of some action and the end of the shot to be able to fade out properly; I suggested maybe using a freeze-frame. This is where I do this if I need to (or even if I don't need to but want to because it gives an effect I want); I capture the last frame of the action then drop it on the timeline immediately after the shot - the NLE by default will hold the image static for 5 seconds. I can then lengthen or shorten that as necessary, and fade it to black or cross-fade into the next shot (for example).

This may also be the best place to fix any audio/video sync problems, but we'll come to that later.

Transitions

Once I've got all the A-reel footage on the timeline I usually play the whole thing from beginning to end so I have a useful first look. I may make more changes to the order of the shots but the main job at this step is to finalize how each shot transitions to the next - hard cut, cross-fade or something else.

If I have a transition that represents a major change - a complete change of scene, perhaps, or to indicate the passage of time - I usually start with a plain cross-fade then experiment by trying other transitions such as linear wipes or maybe even "venetian blind" transitions.

Be careful with using too many fancy transitions because they're distracting; overdone, they'll make your work look amateurish.

B-reel overlays

By this point I should know where I have long, static shots that need some B-reel overlays to add interest. Since I already marked up my B-reel shots ready during the reviewing step, it's just a case of dropping them in place on the overlay track. Normally you wouldn't fade in or out - you just want a hard cut - and you don't normally need the audio track from the B-reel shots.

Often I find that I have static sections where I didn't know enough in advance to get specific B-reel footage to cover. This isn't a catastrophe because usually I can find some odd bits in the footage I cut out during trimming that are good enough to use as B-reel.

Special effects

This is the point where I add any special effects - it's fun to experiment with different effects and combinations. For example, I can increase the speed of a shot 20 or 30 percent, add a sepia tint and some jitter and scratches, and voila, I have something that looks like it was from the silent film era. Most NLEs that I've messed with come with a good package of special effect plugins.

Text overlays and titles

The last step. This is the point where I add any text overlays needed, such as descriptive captions. Also, this is where I put in opening titles and end credits, including the copyright notice and acknowledgements.

A complicated title sequence can be a project in itself - it's a lot of work but very satisfying to do, and adds a professional touch to your movies.

At this point the visual part of the job is done. Now to get to the sound part.

The voice track

Mostly this is straightforward stuff - the voice track from the video files will already be in place and you should have removed the unnecessary B-reel sound. There may be some tidying up to do, though.

The first thing to check is that the audio is in sync with the video. Normally this shouldn't be a problem but as I noted in an earlier post, if you import your data using USB you may find that the sound is out of sync by several frames on some shots. If it is and you didn't already fix it (as I mentioned earlier), now is the time to do that. Hopefully your NLE program will allow you to unlock the audio track from the matching video, "slide" the audio with respect to the video until they sync up correctly, then lock them again.

Listen to the overall sound level as the movie plays. You may need to pull down the volume in loud scenes and push it up in quieter places, to give your viewers an easier time.

Check how the sound is on the transitions between shots. On a blunt cut, the sound may snap in or out unpleasantly - this can usually be fixed by adding a short fade to the soundtrack at that point. If the video track has a crossfade then by default the sound will usually also be faded during the transition. Most times this is exactly what you want (which is why it's the default) but sometimes you may want to do things a little differently.

One common trick is to have the sound from the start of one shot be playing over the end of the previous shot. This is called a "J-cut". The opposite is called an "L-cut", where the sound from the end of one shot continues over the start of the video of the next shot. Both J-cuts and L-cuts are usually simple to acheive, but check your NLE manual for specifics.

Sound effects

Again, usually straightforward. You can get disks containing thousands of sound effects (animal noises, machines, weapons...) usually for just a few bucks; as I have mentioned, you can record your own. Just drop them onto the sound effects track, set the volume and any other adjustments you need, and you're done.

Music track

Very simple - just drop your music files onto the music timeline in the right places, set the volume levels (and modify the envelopes if you need to - refer to your NLE manual for details) and you're done.

The bigger problem is where to get the music in the first place. In general you can't just rip music from a CD and expect to be able to make your video available on Youtube or for sale on DVD - you'd probably be breaking the law.

There are basically three solutions I can think of: (1) Write your own music. Vegas Movie Studio includes Acid XMC and a set of loop files that you can use to create your own music, and other NLEs may be packaged with equivalent programs. (2) Buy royalty-free music. There are disks available filled with music of different styles that you can use for movie and other projects; there are also places you can download music files (they're usually not free). (3) You could always contact the publisher of the music you want to use and ask for permission.

Render

Your movie is to all intents and purposes complete. All that remains is to play it through from beginning to end a time or two to check that it all looks good, and do any last-minute tweaking. Once you're happy with how it looks, you can render the movie to a file.

How you render - that is, what type of file you create - depends on what you plan to do with your movie. For the web, WMV or MOV format is probably the best choice (AVI files are usually far too large). If you're planning to make your movie viewable on an iPod or PSP, you need MPEG-4 format. The standard format for DVD is MPEG-2, with a separate WAV file (usually 48KHz, 16-bit stereo) for the audio track (see your DVD burning software documentation for specifics).

The End

This concludes this short series of articles. Hope you found it useful!

Labels: