Index

Introduction

What do you need?

Video format

Video size

Video capturing

Video transformation

Summery of recommendation

Introduction

 

Video analyzing and comparing is one of the most common widely analyzing technique in sports. Our products gives you the price affordable and still very professional solutions. The great advantage is their simplified user interface and slim design that make it possible to deal with advanced analysis even on the slower or older PC desktop/notebook computers.

 

What do you need?

 

The computer needs for our software solutions are very low. All our products are build for MS Windows 95, 98 SE, Me, 2000, XP and XP pro. Compatibility with higher versions of MS operating systems is not known yet.

We recommend you to use fast computers with a lot of Hard disk free space, but it is not necessary. The programs will work well even with 800 MHz processor (e.g. Intel Celeron), 128 Mb of RAM and 20 Gb Hard drive, but faster computers give an advantage, especially when several videos are being played at the same time. When you want to store more videos on the computer, you need a large Hard drive (see section bellow).

 

Video format

 

Of course, it is an important fact, that our products support almost all AVI codecs depending on the computer settings. This gives the user a chance to decide what he wants to use or what he is already using. Anyway, we recommend you to use Intel Indeo 5 or Microsoft Media 9 codec (you can download them for free from our downloads site).

 

Note: Windows Media player uses its own codecs. Therefore not all AVI codecs that are playable in MP are also playable in SX VC.

 

Normally video clips are captured into DV AVI format. DV format is uncompressed and results in huge video clip files (approximately 18 minutes of video corresponds to 4 Gb of data).

 

Note: Different manufacturers are using even different DV standards e.g. Pinnacle DV AVI. If you want to use such files the appropriate codec should be installed.

 

Because DV format uses a lot of free disk space it is useful to transform DV AVI format into some compressed codecs e.g. Intel Indeo (version 3.5, 4.1, 5.11 etc.), Cinepak, Microsoft Media 9 or similar. Some of the codecs are already installed with MS Windows and some have to be added. The user may freely decide which AVI codec will use, but there are some that are more appropriate and some less. For example DivX codecs reduces the size of the video very well, but the codec is not appropriate for playing videos in reverse which is one of the main functions necessary in video analyzing.

 

Some new camcorders, especially hard disk or CD/DVD camcorders, record video in mpeg2 or DVD format (mpg, mp2, vob or similar files). These codecs takes less free space on the hard drive, but most of the analysing softwares don’t support them. Therefore it is necessary to transform them to AVI codecs. (see transforming video)

 

Video size

 

Normal video size DV standards are 720 x 576 and 640 x 480. Sometimes you will find 720 x 480 or 704 x 480 etc, but in most cases these videos are deformed and therefore not very useful for advanced analysis. Anyway, in these sizes the video is normally captured to the computer. But you have to have in mind, that larger sizes result in longer files, but they are sometimes useful for precise analysing. When comparing videos mostly smaller sizes such as 360 x 288, 320 x 254 or 320 x 240 are used.

When reducing the video size it is smart to reduce the video size to its half. This way deinterlacing can be made by simple extracting of odd or even fields (lines). Such deintalacing results in clearer images and you don’t deform the video. It is very important that when you change the size the aspect ratio horizontal to vertical remains the same!

 

Note: Reducing the video size by extracting even or odd fields unable Odd and Even function in the SX Video Compare v3.3 pro and consequently better time resolution...

 

Video capturing

 

There are several programs that enable video capturing (i.e. recording video from hard drive to the computer hard disk).  Most of them enables to capture video into DV AVI format, and some capture it into mpeg2/DVD format. Normally video capturing goes via Fire Wire (iLink, IEEE1394) protocol / cables and connections.

We recommend you to use WinDV program  (you can download it for free from our downloads site), because it is very easy to use and it enables scene detections as well as to control Type-1 / Type-2 DV AVI. Most of the capturing software don’t allow to manually decide which type can you use and that is very problematic with most of the analyzing software, because they don’t support type-1 format. When using our products it is also necessary to use type-2 DV AVI if you want to analyze video without format transformation (see section bellow).

 

Video transformation

 

We know that video files are pretty large. Therefore they take lots of free space on the hard drive and slow down your computer, especially when running comparative analysis on the computer. Another “video” problem or on the other hand an advantage is interlaced video signal in PAL system (Europe TV standard), where odd and even lines comes separately. You get a jigsaw or blended double “picture” video. Usually it is better to deinterlace video (join together odd and even lines). But there are several techniques how to do it.

Normal transformation

 

Our recommendation would be to use VirtualDub for video transformation (editing) if you are dealing with DV AVI files and VirtualDubMod if you are dealing with mpeg2/DVD files (both can be download it for free from our downloads site). You can do everything you need in one step: deinterlacing, size change and codec transform.

 

How to do it in VirtualDub / VirtualDubMod:

 

1. “File/Open” - Open captured video

 

2. “Video/Compression” - Change video codec.It is very smart to transform the captured DV AVI video files to more suitable codecs (e.g. Intel Indeo 5, Windows Media 9). The new video files will take far less memory and wil make your computer working faster.

a. choose desired codec

            b. set quality to 90 (recommended) or less

            c. set keyframes between 5-10

 

3. “Video/filters/add/deinterlace” - Deinterlacing video will make you image clearer.

choose duplicate field 1 or duplicate field 2 or discharge field 1 or discharge field 2 (the result will be very similar). It is important how you choose it only when you want to have images half a period sooner or half a period later.

 

4. “Video/filters/add/resize” - Reducing size is also important, when you want to compare and analyze videos side by side.

            a. choose appropriate size for you (e.g. 360 x 288)

            b. choose bicubic filter (better image quality)

 

5. “File/Save as AVI” – this will save your captured video in the transformed form under a new chosen name.

 

Note1: the order of applying video filters is important! Normally it is better to deinterlace first and then change size. 

Note2: if you don’t want to type this command everytime, then you cane save all settings by the command “File/Save processing setting” and the next time load them by the command “File/Load processing settings”. In old versions there is a small bug in VirtualDub. After loading processing settings you have to go to “video/filters” and press OK to activate the settings.

 

Advanced transformation (double the video frequency)

 

The good side of the interlaced video is that you can double the video’s frequency (e.g. from 25 Hz to 50 Hz). But in this case you have to use e.g. AviSynth (you can download it for free from our downloads site). The problem of interlacing is now the advantage. Because the odd and even lines (fields) are coming one after another, you can make separate video frames from both of them. This is how you double the number of frames. The technique is known as “fields to frames”.

 

How to do it with VirtualDub (as far as we know it is not possible to do it with DVD files in VirtualDuvMod)?

 

First you have to download Avysinth and install it. It works in the background, so you actually don’t ever see AvySinth. Then, you have to create a new text (ascii) file with a new name and it should have suffix “avs” e.g. “new_name.avs”. Everything you write into this file are these two lines:

clip=AVISource("d:\My Documents\Video\captured_video_name.avi")

clip.SeparateFields

In the first line you give a command where is your captured video. You have to write down the exact location and name of the captured file. The second line gives a command to transform fields to frames. That is all. In case your video will be jumping forward and backward after this command (you will see that in VirtuaDub) then you have to use the inverse command in the second line:

clip.ComplementParity.SeparateFields

 

After creation of such a file, you start VirtualDub. You have to proceed like this:

 

1. “File/Open” - Open avs file “new_name.avs” – the “new” video will look only half high of the normal video. This is the consequence of the “field to frame” command. You will repair this by resizing (see point 3).

 

2. “Video/Compression” - Change video codec.It is very smart to transform the captured DV AVI video files to more suitable codecs (e.g. Intel Indeo 5, Windows Media 9). The new video files will take far less memory and wil make your computer working faster.

a. choose desired codec

            b. set quality to 90 (recommended) or less

            c. set keyframes between 5-10

 

3. “Video/filters/add/resize” – Setting a normal size of the video or the reduced size.

            a. choose appropriate size for you (e.g. 720 x 576, 360 x 288)

            b. chose bicubic filter (better image quality)

 

4. “Video/filters/add/field bob” – A new video will be bouncing up and down for one line. You have to add this filter twice or use similar filters to get rid of bouncing (e.g. field shift – also in VirtualDub). 

choose quarter scan line up for even filed and quarter scan line down for odd filed. In case the image will start to bounce more then you choose just the opposite: quarter scan line down for even filed and quarter scan line up for odd filed

 

5. “File/Save as AVI” – this will save your captured video in the transformed form under a new chosen name.

 

Summery of recommendation

 

Our recommendations would be to use WinDV for capturing, VirtualDub/VirtualDubMod and AviSynth for video editing (transformation), Intel Indeo 5 or Windows Media 9 codecs (all freeware), SX Video Compare v3.3pro and Avi AD Measure v2.4 for video comparing and motion analysis.