High-Precision Deep Zoom

Technical Info

If you are having trouble downloading video files

Click and nothing happens

If you click on a link to a video file, your browser will generally try to play it. This can take a very long time to start if the file is large. Not all browsers give immediate feedback when a video file is being downloaded and prepared to play. If you click on a video file link and nothing happens, it may be that the browser is downloading the file and just not starting the video player right away.

Note: This is as true in 2011 as it was in 2009:

Internet Explorer (yes, even IE9) does not like to start Quick Time when you click on an MP4 file.

I am not sure why this is so, but it's been going on for years. If you want to click on a video and see it start right away, try selecting a WMV file, or try Firefox, Safari, or Chrome. They all play MP4 files properly when they're clicked.

Here is a table of what happens when you click on a hyperlink to a video file in different browsers and with different video file types (as of June 2011). This testing was all done with browsers running in Windows 7 Professional 64-bit, and with no special configurations of the browsers. This is what they do as delivered, freshly installed right out of the virtual box.

Internet Browser Video File Playback Behavior
Internet Explorer 9.0.1 Downloads silently then launches QuickTime Launches Windows Media Player and plays while downloading
Firefox 4.0.1 Launches embedded QuickTime and plays while downloading if FastStart formatted Downloads without playing
Google Chrome 12.0.742.100 Launches embdeedd QuickTime and plays while downloading even if not FastStart formatted Downloads without playing
Apple Safari 5.0.5 Launches embedded QuickTime and plays while downloading if FastStart formatted Prompts to Open or Save, then downloads entirely without playing

Not surprisingly, Microsoft favors WMV files, and everyone else disfavors Microsoft.

A quick first-line test if you are not getting video playback when you feel you shoudl is to check to see if your internet link is transferring data (network hub light, cable or DSL modem activity light, etc.).

In addition, if you don't have your browser properly configured to play video files, it may not recognize the file types as video files and may not know to start a player to play them. This is a potential problem for all browsers and file types except maybe Internet Explorer and WMV files, and it gets pretty complicated. See the next section for more information.

File not found

If you get a "File not found" error ("404") please send an email to webmaster@hpdz.net describing the link that is not working.

How to download and save files

If you want to save the file to your computer and then play it, try right-clicking on the link (on a Windows PC). Internet Explorer, Firefox, Chrome, and Safari will bring up a menu that offers an option to save the file.

If you are having problems with MP4 files not starting when clicked

Fast Start and Progressive Download


Progressive download (PD), also known as "Fast Start," is the ability of a video player to start playing video files as they are downloaded, rather than having to wait for the entire file to be received before playback can begin. Both Windows Media Player and Apple's QuickTime player support PD. However, the video files must be encoded correctly, and both the web site hosting the video file and the browser viewing that site need to participate correctly for PD to work.

The effect is similar to streaming video, but there are technical differences, and progressive download is not the same as streaming. This site does not use streaming at all.


Windows Media Video (WMV) files, when clicked in Internet Explorer, will launch Windows Media Player and play with Progressive Download.

Files other than WMV require special encoding to support PD. Most MP4 files on this site, as of May 2009, do not support PD. SecantAnimation1 is the first group of MP4 files that are encoded properly for this to work.

Files on this site with the MP4 extension are encoded using an H.264 AVC codec.

Web Site and Web Browser

For PD to work, the web site needs to tell the web browser what type of application should be used to play a video file. The proper information for that file association was not configured on HPDZ.NET until late April 2009.

However, providing this information at the web site is not enough to ensure will PD work on a particular system. The web browser being used to view the site must comply with the file association information it receives and launch the correct player. Internet Explorer works internally differently than most browsers in this respect and does not always use this information from HTML hyperlinks properly, and therefore IE may not launch QuickTime when an MP4 file is clicked.

Firefox, Safari, and Chrome have been tested with the fast-start encoded files on this site, and they do not have this problem. If you are experiencing difficulty getting videos on this site to start QuickTime (or whatever other player you have for MP4 files), please try switching to a different browser. The other alternative would be to download the files in their entirety and then play them in your video player after the download is complete.

Test Links

Below is a set of video files (no audio stream, to help simplify things) that should be sufficient to diagnose most download problems.

Windows Media Player

If you are using Windows Media Player, click on item 1 (the WMV file) and it should start playing. If it doesn't, then you may have assigned a different player to the WMV extension. If Windows Media Player starts but does not play the video file, you may also need to download the latest version of the player. All WMV files on this site require at least version 9.

MP4 (QuickTime)

Note: Internet Explorer will not start QuickTime when MP4 or MOV files are clicked. This is a limitation of the way IE works. If you want to experience fast start with these files, you will need to use a different browser. Adapting this site to handle it would require changing how all the links are set up and is too large a project for now. Sorry. Additional information is available from Apple.

If you are using a browser other than IE and trying to play MP4 files, click item 2. It should start your MP4 player and begin playing the animation. If it does not, try item 3. If 3 plays then your system may not be set up to recognize the MP4 file extension.

If your player starts when you click on 2 or 3, but it cannot play them, you may not have an AVC codec installed. Try clicking item 4, which uses a different, older, video codec. If it plays, but 2 and 3 do not, then you will need to obtain an AVC codec. If none of these plays, try item 5, which was encoded without fast start. If this downloads and then plays properly, your browser is probably not configured correctly for fast start. If it downloads and does not play, you may not have a video playback plug-in installed in your browser.

Clear your cache

To be sure you are getting fast start and not just playing the video files from your browser's cache, you should clear the cache if you click more than once on any of the links.

Downloading too fast to be sure?

Item 6 can be used as a double-check that your player is really playing as it downloads. It is much longer than the other files.

Test Links
1. HyperNova.wmvShould open Windows Media Player and start playing while it downloads
2. HyperNova-FS.mp4AVC1 file with Fast Start
3. HyperNova-FS.movAVC1 file with Fast Start renamed to MOV extension
4. HyperNova.movEncoded with MP4V codec and Fast Start
5. HyperNova.mp4Encoded with AVC1 H.264 codec but NO Fast Start
6. HyperNova-512Kbps.movMP4V codec at 512Kbps and Fast Start