Martin Francis

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Martin Francis - Web designer in Bristol


Thursday 27 August 2009

Broadcast Quality Video Sequence on the Web.

What are the technical considerations and typical workflow process involved in capturing, editing and exporting a broadcast-quality video sequence using a video editing software application like Adobe Premier Pro?

This sequence could equally apply to Final Cut Pro (Mac) or Pinnacle which are both excellent for editing video.
Having prepared a resource folder ready take in items for your project, the sort of raw files you may start with are:-
Video Clips - Flash SWF, AVI, MPEG 1&2, Quicktime, Windows Media WMV files.
Sound Clips - Audio AVI, MP3, Quicktime Audio, Windows Media WMA files.
Still Images - JPEG, TIFF, GIF, PSD, and even flm files.

You will also need a PC or mac with a fast processor, and large amount of hard drive space. Video projects are large while you are working on them, before they are finally compressed ready for broadcast on the web. Two monitors make thinks easier too. One with your resources and one with your constructed sequence.
Now launch Premier Pro, open a project folder and choose what sort of output format you will need for broadcasting. For example for television, (not HD) you will need to choose to output at 31Megabytes (MB) per second. Now you can see why you need the high end processing power!!
Next choosing the depending on the country of broadcast you may choose Phase Alternating Line (PAL) or National Television System Commitee (NTSC) which for colour TV is 720 x 576 pixels and 720 x 480 pixels. The 31MB per second comes from multiplying the number of pixels by the frame rate (frames per second - fps).

PAL = 720 x 576 x 3 (RGB) x 25 fps = 31MB/s
NTSC = 720 x 480 x 3 (RGB) x 30 fps = 31MB/s

Where RGB stands for Red, Green, and Blue, one pixel for each colour.

This may seem overkill to talk about TV broadcast quality but broadband speeds are getting faster all the time plus it is better to have a really qood quality version of your finished sequence that can always be compressed to match the broadcast medium later.

Now at this point you can click OK and start your project proper.

Bring in any resource files to the project folder which is on the far left of the Premier Pro inferface. You can then preview any of these files by dragging and dropping them into the source screen.
Using the scrub wheel you can easily find the points you need to mark. Marking the start and finish of the segment you want with "outpoint" which look like curly brackets. Then simply drag and drop the segment to the timeline which appears at the bottom of the Premier Pro application.
Repeat this adding the segments to the timeline while previewing what is on the timeline in the sequence screen.
You can also do more accurate editing using the timeline.
Audio is added to it's own timeline and can be edited in Adobe Soundbooth.
Premier Pro has a long list of transitions and effects that can be added to your sequence. For titles, and credits etc it is best to switch over to Adobe After Effects. This is done seemlessly from Premier Pro.
And finally when finished the sequence can be compressed or flattened ready for broadcast. At no point were the original resource files edited or erased.

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