Hi Guys,
Some of you have been having problems exporting your soundtrack from Final Cut. If you've had issues with the sound freezing and stuttering in your Quicktime files, check to see if you've got any .mp3 files in your edit. Final Cut really doesn't like editing mp3 sounds 'natively' ( i.e. without converting it to some other format first).
You should always use uncompressed sound in your Sequence. Compressed formats such as mp3 cause lots of problems; for example, Final Cut has to render the file before it will play back slowing down the overall editing process, mp3's are often so compressed that the sound quality starts to suffer, and finally, lots of mp3's use variable bit rate encoding which can lead to timing and sync issues.
No professional editor would use mp3's on their soundtrack so you shouldn't either! The same goes for other compressed formats such as OGG, AAC, or WMA.
Always use something like Soundtrack Pro or iTunes to convert your compressed files into AIFF files before you start editing in Final Cut.
Check the blog post about converting files to AIFF using Soundtrack Pro. Your audio file settings should always match the settings of your Final Cut project. For the DMW this will be set to: 16 bit integer, 48000 samples / second.
Happy Editing!
Wednesday, 25 January 2012
Saturday, 14 January 2012
DaVinci Resolve Lite
BlackMagic DaVinci Resolve Lite has been installed in all the Digital Media Workshops. If you are TVP or TVP Tech Arts student learning about colour correction, you can use any open access workstation to correct your footage or just spend time learning the software. The Resolve manual and sample files are available in the folder /Users/Shared/Resolve
How to Key a Green Screen Shot With After Effects
Hi everyone!
Loads of you have been asking about shooting on green screen so here's a quick tutorial covering the basics of chroma keying with After Effects. I'll be showing you how to 'pull a matte' from your green screen shot with Keylight, then replace the background with another still image or video.
First things first: setting up the project.
Open up After Effects and click on "New Composition" on the Welcome screen
On the Composition Settings window, set up the resolution and frame rate to match your video. If you're using the JVC HM100 with our standard settings, you'll want to set this to HDV 1280 by 720 at 25 frames per second
After that click OK then import your video from the Film menu.
Next you will need to drag your video onto the viewer of your Composition. You'll see an outline of the frame to help you line up the footage.
The box will snap to the edge of the Composition to make sure its centered properly.
Now the Comp is set up, you're ready to add a keying effect to the video. Click open the Keying section of the Effects & Presets panel and find KeyLight (1.2)
Drag it onto your video strip in the timeline and let go. You should get the Keylight controls appear on the left of the screen.
Find the setting called "Screen Color" and click on the eyedropper next to the Black colour swatch. Use the dropper to select the green colour of the background. You need to pick a part of the screen with an average green tone, not over-lit or under-lit and not too close to the foreground subject otherwise you'll risk picking an off green colour which doesn't match the actual colour of the backing.
It looks like nothing has happened, but if you go to the View setting and pick "Screen Matte" from the menu, you'll see the alpha matte you've just made from the green screen plate.
This grey-scale image is what will make your video semi-transparent. Solid Black is completely transparent and lets the background show through, Solid White is fully opaque and shows the foreground image.
There are a couple of problems with the matte right now. Firstly there is some grey noise in the background especially in the corners. This is going to make the green screen show through a bit and discolour the background. Second, there are patches of grey on the actress particularly on her dress. Remember, anything but solid white is going to be slightly transparent so in the final shot you'll see the background showing through her body. To fix this, you'll need to increase the contrast of the matte image until the background is solid black and the actress' body is solid white.
Her shawl is trickier because its naturally transparent and needs to stay a shade of grey.
Keylight provides settings to control the matte's contrast. Click on "Screen Matte" to open the controls, then click open "Clip Black" and "Clip White"
Increasing the Clip Black will start to 'eat away' at the noise in the background. Turning down Clip White will start to fill in the grey regions of the dress. Its REALLY important that you adjust the sliders by the absolute minimal amount that gives a good result. If you over do it, you'll damage the matte image and end up with an ugly final composite.
Finally you should test the matte to check its giving good results. The best way to do this is by putting a coloured solid behind your subject. To add a solid, click on the matte image, then go to Layer -> New -> Solid
Make sure the size matches your original video resolution then pick a bright red with the colour swatch.
Click OK and the new Solid will appear on the timeline. You may have to re-order it in the layer stack to get it behind the video by using the Layer -> Arrange menu. Finally you'll need to set the View property of Keylight back to "Final Result".
Hopefully you should have a nice clean foreground subject on a solid red background. If not, go back to Keylight and adjust the settings until you get a good, clean key. Once you've done that, you can swap the Red Solid for a still image or video and you're done!
That's it for now. If you're trying a green screen shot and get stuck any of the DMW technicians will be able to help you out.
"Govida Close" Green Screen Plates are copyright Hollywood Camera Work
Loads of you have been asking about shooting on green screen so here's a quick tutorial covering the basics of chroma keying with After Effects. I'll be showing you how to 'pull a matte' from your green screen shot with Keylight, then replace the background with another still image or video.
First things first: setting up the project.
Open up After Effects and click on "New Composition" on the Welcome screen
On the Composition Settings window, set up the resolution and frame rate to match your video. If you're using the JVC HM100 with our standard settings, you'll want to set this to HDV 1280 by 720 at 25 frames per second
After that click OK then import your video from the Film menu.
Next you will need to drag your video onto the viewer of your Composition. You'll see an outline of the frame to help you line up the footage.
The box will snap to the edge of the Composition to make sure its centered properly.
Now the Comp is set up, you're ready to add a keying effect to the video. Click open the Keying section of the Effects & Presets panel and find KeyLight (1.2)
Drag it onto your video strip in the timeline and let go. You should get the Keylight controls appear on the left of the screen.
Find the setting called "Screen Color" and click on the eyedropper next to the Black colour swatch. Use the dropper to select the green colour of the background. You need to pick a part of the screen with an average green tone, not over-lit or under-lit and not too close to the foreground subject otherwise you'll risk picking an off green colour which doesn't match the actual colour of the backing.
It looks like nothing has happened, but if you go to the View setting and pick "Screen Matte" from the menu, you'll see the alpha matte you've just made from the green screen plate.
This grey-scale image is what will make your video semi-transparent. Solid Black is completely transparent and lets the background show through, Solid White is fully opaque and shows the foreground image.
There are a couple of problems with the matte right now. Firstly there is some grey noise in the background especially in the corners. This is going to make the green screen show through a bit and discolour the background. Second, there are patches of grey on the actress particularly on her dress. Remember, anything but solid white is going to be slightly transparent so in the final shot you'll see the background showing through her body. To fix this, you'll need to increase the contrast of the matte image until the background is solid black and the actress' body is solid white.
Her shawl is trickier because its naturally transparent and needs to stay a shade of grey.
Keylight provides settings to control the matte's contrast. Click on "Screen Matte" to open the controls, then click open "Clip Black" and "Clip White"
Increasing the Clip Black will start to 'eat away' at the noise in the background. Turning down Clip White will start to fill in the grey regions of the dress. Its REALLY important that you adjust the sliders by the absolute minimal amount that gives a good result. If you over do it, you'll damage the matte image and end up with an ugly final composite.
Finally you should test the matte to check its giving good results. The best way to do this is by putting a coloured solid behind your subject. To add a solid, click on the matte image, then go to Layer -> New -> Solid
Make sure the size matches your original video resolution then pick a bright red with the colour swatch.
Click OK and the new Solid will appear on the timeline. You may have to re-order it in the layer stack to get it behind the video by using the Layer -> Arrange menu. Finally you'll need to set the View property of Keylight back to "Final Result".
Hopefully you should have a nice clean foreground subject on a solid red background. If not, go back to Keylight and adjust the settings until you get a good, clean key. Once you've done that, you can swap the Red Solid for a still image or video and you're done!
That's it for now. If you're trying a green screen shot and get stuck any of the DMW technicians will be able to help you out.
"Govida Close" Green Screen Plates are copyright Hollywood Camera Work
Character Training for Maya and Unity
3D Buzz are running an online training course for 3D character development with Maya and Unity. Check out the videos here
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