dvfs api and toolkits

[Nate Nielsen]

Avery Pennarun wrote:
> On Sat, Apr 09, 2005 at 04:33:29PM -0400, Sean Middleditch wrote:
> Movie players are, however, a good example of where seekability might be
> important.  

<snip>

> That said, this is a pretty special case.  

I beg to differ.

- Read an archive format like ZIP, TGZ or ISO  User opens the file in
  their choice of archive manager. The user then proceeds to extract
  a file. Now the entire ISO/ZIP/TGZ (your choice of archive format)
  needs to download until the point of the file to be extracted.

- Note that some archive formats don't contain the 'file content list'
  at the front. In some cases it's at the end of the archive.

- ID3 version 1 tags are (mostly) stored at the end of MP3 files. To
  display information about an ID3v1 marked MP3 file, a music player
  would have to wait for the entire file to be loaded.

- PDF viewers often choose to to seek around, showing text and skipping
  large images. PDF's can be very large in many settings. A good PDF
  implementation allows the user to go to different pages before the
  images or even the entire content of their previous page has completed
  loading.

- Seeking in a movie is of course a show-case example. The user doesn't
  (or rather shouldn't) expect the massive wait involved.

These are just some examples. And note that these are in fact
'documents' as far as the user is concerned. The user is working with
his document (or music file, movie, whatever), and isn't expecting the
kind of delays we're talking about here.

Ideally file (ie: document, movie, archive, music) formats wouldn't have
these issues. But because we don't live in an ideal world so we have to
consider these things.

Cheers,
Nate