Discovery about "video" and involvement of video card...

[Lin Evans]

I had always assumed that once a PTE file was converted from EXE to "video" that a video frame was pretty much a video frame regardless of content. That is, I assumed that if a video card could smoothly play "video" such as from a DVD, that it would play any animations as easily as it would a simple slide because animations are, in video terms, simply the result of sequential different frames. So does it take more video clout to play frame a or frame b? Apparently there are differences depending on the frame content. Obviously there are difference depending on the number of pixels constituting the frame, but logic has always told me that as long as the pixel count is the same, one frame is just like another to video. It would seem that this is not so....

This turns out to apparently not be true. In a recent experiment "Dreams" published on the "Slideshows" forum, I discovered that adding a few masks each containing identical png animations greatly taxed both the executable presentation "AND" to a lesser degree, the video presentation. Surprisingly, at least to me, on my older system with an 8086GT nVidia card, the video portion of animations with the masks played smoothly, while the main HD (1280x720) video portion was compromised. In later testing with the compromised video card and web player, both the snow and flames were jerky. So a word to the wise - if you make a complex show mixing animated still frames "and" video, you might find that viewers with less than optimal video cards may have issues with smoothness.... I must do some more testing by playing the older version on my older system (same resolution different frame content) and see what happens.

After more testing, it gets even more confusing.... I put both the "old" and "enhanced" versions on a thumb drive and played them on my old system with Kantaris Media Player. They were identical in smoothness, etc.

I played the "web version" with both my development system (fairly powerful video card) and my old system (weaker video card) and even after allowing 100% buffering, the old system still stuttered on the flames animation with the enhanced video while the development system played it perfectly smoothly.

This now brings the "player" into the equation. There is an approximately 20 meg difference in the MP4 file size. This leads me to video "compression" because the actual image sizes per frame in pixels are identical. So where the problem appears to lie is in the time it takes the "player" and system to decompress the individual files. Apparently this goes faster with the more powerful video card and hence the smoother play on the web player version. So the "player" can make a significant difference especially with a compromised video card!

Best regards,

Lin