Video on the Web John H. Krantz Hanover College

Outline What is Video Acquiring with a Digital Camera Creating with ImageJ Editing with QuickTime Delivering in a Webpage

General Video Issues Image size Keep it small 320 x 240 is not uncommon Image color depth Normally full color Video Length The shorter the better This file is ~ 5.5 meg in QuickTime and it is 17 seconds

General Video Issues Frame rate: recall difference between apparent motion and flicker 10 to 15 is really fine for most cases And best you can expect on web

Acquiring with a Digital Camera Find format of your video camera mine is QuickTime Can use digital zoom original camera images are much larger than movie images so will be shrunk down And digital zoom is before movie image

Acquiring with a Digital Camera Hold camera still or not? Movies are limited in duration mine is 30 sec or size of disk for 320x240 It is 120 sec if 160x120 Image quality is reasonably good if presented in original size But image quality may be reduced to get on web

Creating Animations with ImageJ Stacks Sequence of images to be played Found under Image menu Open the desired sequence in order Image: Stacks: Convert Images to Stack Can add and remove images (a Slice) under the same menu

Create Animations with ImageJ Stack Menu Can control frame rate under: Image: Stacks: Animation Options Get AVI writer plugin to save as a movie

Create Animations with ImageJ Useful for making a slideshow A frame rate of 1 frame per second is good And as slow as can have in ImageJ

Slideshows Can also do slideshows in web pages In FrontPage it is built in Insert: Web Component Dynamic Effects: Banner Ad Manager Limited in number of images to 9 Here is an example

Slideshows Or the following Java Script Not limited in number These do not stop but can go slower

Editing with QuickTime Pro Open more than one Basics Opens MOV, mpg, avi, mp3, etc. Get Movie Information on Movie Menu (ctrl-j in Windows) Tracks: separate slices of information: played at same time as other tracks Look under the Edit menu

QuickTime Pro Interface Playback head In marker Out marker Selected region

Basic Editing Selecting a region to edit Use guides at bottom Called In and Out Markers Selected region is darkened Arrow keys to fine tune Cut and Paste operation Paste is at playback head

Adding Tracks Copy as before Use Edit: Add – adds the video track Use Edit: Extract Tracks Then Edit: Add Can extract sound this way to a movie Can add scaled so new track is not length of old movie

Deleting Tracks Use Edit: Delete Tracks Remove any unwanted sound from video

More Advanced Editing with QuickTime Pro Adding text to beginning Make any graphic Resize to movie size so know how it will look Select al (ctrl-A) Then cut and paste to beginning Another paste for each additional frame

More Advanced Editing with QuickTime Pro Overlaying Text Use a gif file with a transparent background Use a text file File: Import Any.txt Press Option button –Select keyed text –Change background to white and foreground to text color –I like changing it to bold Add tracks as before

More Advanced Editing with QuickTime Pro Filtering portions of movie Delete regions do not want to filter Use the export function Click on Options Click on Filter Pick pattern Use cut and paste to reassemble

Saving for Web Format: You must compress Uncompressed files will be very large Lead very slow download Duration For same reason, keep videos short

To Stream or Not to Stream Steaming Starts sooner Can be large files Can stop Generally low quality General Protocol RTP/RTSP Regular Delivery Wait for entire file Keep to small files Keeps Speed Better quality

Streaming vs. HTTP Fast Start HTTP Fast Start is a feature of QuickTime Allows playing after part of file downloaded Fewer stops No special software Still keep files relatively small Some loss of image quality

Embedding a QuickTime Movie in a Web Page