Video Capture Overview

 

 

Introduction

Before you begin capturing your video, you need to decide which resolution you want to capture in.  Depending on the final format of your video, your quality preference, and the capabilities of your computer, you will want to capture in either high resolution or low resolution.  High resolution video is any video captured at XXX by 480 (NTSC) or XXX by 576 (PAL/SECAM).  Low resolution video is any video captured at XXX by 240 (NTSC) or XXX by 288 (PAL/SECAM).
To learn about the advantages and disadvantages of high resolution video, see my article entitled High Vs. Low Resolution Capture.  To learn about the differences between NTSC and PAL/SECAM video, read my article entitled NTSC Vs. PAL/SECAM.

You also must decide what capturing software you're going to use.  The two most popular programs are AVI_IO and VirtualDub.  Here is a brief comparison of them:

AVI_IO VirtualDub
  • Sometimes keeps better audio synch than VirtualDub
  • Sometimes drops less frames than VirtualDub
  • Easier to set up than VirtualDub
  • The free trial version is limited to capturing 3 segments of video up to 4 GB apiece
  • The full, non-limited version costs $25 (US)
  • More configurable than AVI_IO
  • Has capture features that AVI_IO lacks (e.g. field swapping, vertical reduction, etc.)
  • Freeware (it costs nothing)


Choosing Your Capture Resolution

Below I have made some tables that recommend the capture resolution for the most common forms of output video.  Please note that not all capture cards will be able to capture in the resolutions I suggest.  In this case, you will have to capture at the next highest resolution your capture card supports and resize the video during processing.

Low Resolution Capture with AVI_IO -- Low Resolution Capture with VirtualDub
Desired Output Video Recommended Capture Resolution
Average quality 320 x 240 computer video (NTSC) 320 x 240
Average quality 320 x 240 computer video (PAL/SECAM) 320 x 288
Average quality 384 x 288 computer video
(native PAL/SECAM resolution)		 384 x 288
Average quality VCD (NTSC) (352 x 240)

352 x 240 (*1)

Average quality VCD (PAL/SECAM) (352 x 288) 352 x 288

(*1)  If your capture card doesn't support this resolution, it's probably acceptable (but not preferable) to capture in 320 x 240 and resize to 352 x 240.  The best choice, however, would be to capture in a high resolution (352 x 480 or 640 x 480) to create a high quality VCD, as described in the table below.

High Resolution Capture with AVI_IO -- High Resolution Capture with VirtualDub
Desired Output Video Recommended Capture Resolution
High quality 320 x 240 computer video (NTSC) 320 x 480
High quality 320 x 240 computer video (PAL/SECAM) 320 x 576
High quality 384 x 288 computer video
(native PAL/SECAM resolution)		 384 x 576
High quality VCD (NTSC) (352 x 240) 352 x 480
High quality VCD (PAL/SECAM) (352 x 288) 352 x 576
SVCD (NTSC) (480 x 480) 480 x 480 (*2)
SVCD (PAL/SECAM) (480 x 576) 480 x 576 (*2)
512 x 384 computer video (NTSC) 512 x 480
512 x 384 computer video (PAL/SECAM) 512 x 576
640 x 480 computer video (NTSC) (*1) 640 x 480
640 x 480 computer video (PAL/SECAM) (*1) 640 x 576
768 x 576 computer video (PAL/SECAM) (*1) 768 x 576

(*1)  I only recommend using these resolutions if you have a fast computer (greater than 500 MHz) and a very clean video source.

(*2)  Depending on your capture card, capturing video at this resolution for a SVCD may not produce a perfect aspect ratio unless you pad the video with additional pixels.  SVCDs require a non-square pixel aspect ratio, which can be a bit confusing.  (Visit this page for more information.)  However, a slightly incorrect aspect ratio will not be noticeable, so most people probably shouldn't worry about it.


Please go to the page found in the heading of the table containing your desired output video.  Make sure you remember which resolution you need to capture in.