Exercises - MC

• Compare compressed vs. uncompressed sound files.
• Compare compressed vs. uncompressed image files.
• Compare compressed vs. uncompressed video files.
• Look over routines for JPEG compression. In particular:
  • Find
    and tell the instructor the line numbers where zig-zag encoding coefficients and also the line numbers where DCT quantization coefficients are given in routine jddctmgr.c. Hint: each of these looks like a table of numbers. If you prefer, just paste the relevant lines into your message instead of counting lines.
  • On video.cs.vt.edu take a look at the files in ~fox/jpeg
  • Read over how to compress a file using "man -M /usr/local/man cjpeg" and how to decompress a file using "man -M /usr/local/man djpeg". Then you can run those routines on some image files like testout.ppn in ~fox/jpeg and put the output in your own directory so you can use "xv" to display it. If you prefer, instead of using "xv" you can FTP the output files to your diskette in the lab and view them there. Probably the easiest approach is:
    • Make sure in your home directory you have directory public_html;
      if not you can say
      mkdir ~/public_html
    • Run cjepg as in
      cjpeg -quality 25 ~fox/jpeg/testout.ppn > ~/public_html/testout25.jpg
    • Use Netscape to view that file by opening the URL
      
      http://video.cs.vt.edu:90/~name/testout25.jpg
      
      where your login ID replaces "name" above
  • Send the instructor brief comments on the visual quality of files produced by cjpeg with various parameter settings.
  
  
• OPTIONAL: Look over the QuickTime programs (*.c)
  in the Assignments/CS4984/MIS_QuickTime/Programmers
  folder (e.g., OneShot, QuickTrivia) in the Derring Lab and comment briefly what the purpose is of 2 of the routines included.
• Describe for the instructor Storyspace, KMS, HyperCard, WWW in terms of the Dexter and Amsterdam models. In particular, discuss:
  • if and how composite nodes are structured,
  • if links can have multiple destinations,
  • if links are birectional,
  • if links can point into locations inside nodes,
  • what multimedia linking support is provided,
  • any special presentation capabilities,
  • any other special capabilities.