Slow frame rate of video

[richib2002]

Hi:
I have a SDL running pro logging and a VSM. When I view a synced video file through I2pro it has a very slow frame rate (around 5fpm) until you click the mouse on the video window, at which point it runs at a normal rate.

This becomes a problem when you have an overlay file open and are comparing the two video files as one runs at a normal rate and the other at the reduced rate.

The computer is a new acer laptop with 3Gbyte of memory

Any clues

Rich
Powerstation UK Ltd.

[JamieA]

Rich,
This is actually a known 'feature' of i2.

The way video works within i2 is that whichever component on the worksheet has focus is the master of the other components. So if you animate the time/distance graph, then the time distance graph takes control.

i2 then runs the time distance graph at the requested speed, (normally 1:1) and the other components attempt to keep up. In this instance, when the TD graph goes to a point, it asks the PC to grab a specific video frame, that matches this point in data. So the PC is just asked to do a frame grab of that point in time. The faster the PC, the less compression on the video, the better the video card, the more flowing this will appear. the slower the PC, the less regularly the video frames update.

When you select a video component, it becomes the master of the speed. We then put the video through the PC's video playing hardware, and just let it run, as it would outside of i2. We then ask all other compenets, including 2nd or 3rd videos to keep up. They, then, dont get hardware video playing, but frame grabs to match the playing video as best as possible.

High end laptops with good quality external video cards can do this reasonably well. Desktops are usually very good at doing this, and with high end desktops, it can be difficult to see the differences between the 'playing' and the 'syncing' videos.

We have tried just playing both videos in hardware within i2, and although they both play very smoothly, you just cannot keep them in sync with each other, which is the whole idea of i2 video sync.

Regards.

-Jamie

[richib2002]

Thanks Jamie, better lap top needed then!

[jhidley]

Jamie,

I've just run into what I believe to be the same problem. I have two videos synced to the data on a worksheet. Most of the time that you play the videos and data, the video with focus plays at a normal frame rate and the video without the focus plays at about 1/2fps. If you then click on the second video to give it the focus, it plays at a normal frame rate and the first video plays at 1/2fps. Sometimes, both videos will play back smoothly. I have been unable to figure out exactly what combination of patting my head, rubbing my stomach and clicking with the mouse achieves this yet.

The computer in question is plenty fast, with a fast video card and plenty of RAM. Intel 2.8GHz i5 (quad core) 760 with 8MB RAM and Quadro FX 580 video card.

Are you suggesting that if the videos were converted into an uncompressed format that the playback would be much smoother on the video without focus, as the frame grabs would be nearly instantaneous?

A possibly related question. The Frame Forward and Frame Back buttons work very strangely. You can click them 10-20 times with no change in the video. Then other times click them once and the video frame changes as expected. Most of the time they do not work. Any ideas what is going on?

[jhidley]

I just installed the Motec recommended Video Codec, ShowCase. It has significantly improved the problem of low frame rate on one of the videos. You can barely tell any difference now.

http://www.motec.com/filedownload.php/S ... docid=3349