Capture with VirtualDUB

This manual will help you get the most from your video capture card, using VirtualDUB. Generally TV tuner cards are delivered with a capture driver and capture software but you have no access to capture parameters. With VirtualDub you have access to all parameters, and for example, with appropriate settings you can capture at DV size: 720x576 25fps in PAL format or 720x480 29.97fps in NTSC format.

DV format (720x480 and 720x576) is the same as DVD-Video format and is becoming the standard for full size video. I recommend that you capture analog video in DV format as well (so all post processings will be identical).

The most common chip for TV tuner cards is the BT8x8, so the manual is illustrated with the common Pinnacle PCTV.

1. Required software & installation
2. Preparing your system, calibration
3. File settings
4. Audio settings
5. Video settings
6. Capture settings
7. Start and monitor the capture
8. Variant: capture with MJPEG codec

1. Required software & installation

Required software packages to capture video are:

• VirtualDub
• Capture driver
• Huffyuv codec

Assuming your capture card software is installed properly, a capture driver is also installed. Download VirtualDub (latest release) and unzip the archive in a folder of your choice (for our example E:\DVTools\VirtualDUB\vdub_14d).

Now you can create two useful short-cuts:

• VirtualDub.exe
• AuxSetup.exe

Download Huffyuv archive, unzip all files into a folder, say E:\DVTools\Huffyuv and right click on huffyuv.inf and select "Install".

2. Preparing your system, calibration

We recommend that you dedicate a partition and a folder for capturing (say G:\Rushes). Before a series of captures, you should empty or defrag the partition. During the series of captures you never delete files so the partition is never fragmented.

To get the most out of your system, you have to benchmark it, open AuxSetup and push Benchmark:

1. choose the drive to test (partition G:)
2. disable Windows buffering
3. set 200 for total megabytes to read/write
4. start peak disk performance test

The sustained write performance is what we want to know:

With such a high sustained write rate 32,539KB/s , you can capture uncompressed video in full size.

Capture format is YUY2, so 8 bits for Luminance and 8 bits for Chrominance, let's see the data rate we need for DV size:

DV format uncompressed requires 20,250KB/s for PAL and 20,230KB/s for NTSC for the video stream. The audio stream requires 172KB/s.

Anyway, we can capture with Huffuyv codec, a lossless codec (it works like a zipper: output frames are exactly like the initial uncompressed frames). The usual compression rate for Huffyuv is from 1.5:1 to 2.5:1 so the video data rate will be from 8,100KB/s to 13,500KB/s.

Therefore, with a hard drive sustained data rate at 14MB/s and above, one can capture analog video in full DV format.

3. File settings

Now, close AuxSetup and run VirtualDub, choose File - Capture AVI...

You must set the capture file in the capture partition (G:): File - Set capture file... and select G:\Rushes\capture.avi .

4. Audio settings

Usually, CD quality is set for capture: 44.1KHz stereo 16 bits 172KB/s.

5. Video settings

Select the video source (Tuner, composite or Y/C and PAL, SECAM or NTSC) and the format Video - Set custom format... :

For this example, I captured in DV PAL format: 720x576 YUY2 (for NTSC choose appropriate vertical resolution at 480).

Select the compression codec Video - Compression... :

Select Huffyuv, eventually click Configure and set Fastest options.

Generally, the large formats cannot be captured in overlay mode, so set to Video - Preview mode :

6. Capture settings

Disable Windows write buffering in Capture - Disk I/O... :

In Capture - Settings... :