5/01/2021

Using VirtualDub 1.9.11 to capture Video from ADVC-55 on WinXP

VirtualDub is a pretty old, familiar program to most people.

It starts in Edit mode, but you can go into Capture AVI mode from the File menu.

However with the ADVC-55 the initial window is Blank or Black with no sound.

To begin preview, the AVC Tape controls must be used to "Start" the Preview.

This is rather un-intuitive.

Normally you:

1. Go to Device  "to select" > Microsoft DV Camera and VCR (DirectShow)

2. Go to Video "to select"  > Video source (not necessary with ADVC as it auto selects Input)

3. Go to Audio "to select" >  Enable audio playback

 

But the display will remain Blank / Black

 

For a Firewire or ADVC device you also need to:

4. Go to Video " to select" > Capture filter ...


A Dialog called "Digital VCR Control" appears, simply Press the green Play button [ > ] and then Press [OK] to close the dialog and return to the running Preview.

This is rather different from other programs like Windows Movie Maker, in that in those you have to configure the program to allow "Manual" rather than "Automatic" capture control. -- In fact its the opposite procedure conceptually.

It makes apparent that most capture programs will attempt to "Start" the stream by itself automatically when the program starts, rather than waiting for the User to queue up video manually on a playback device, or to start the stream. This can be a problem for things like DV codecs since they cannot start until a video signal is actually coming into them.. they will produce an error code. With a real DV camcorder or video camera capable of reacting to the Start command, the video signal starts playing before the codec is engaged and there is no error.. but not so for a standalone DV codec which expects a video signal to be present and will fail and shutdown if one is not present before starting the encoder.

Its just not a step that most people consider, they assume "something" will send a blank signal which the encoder can use to start producing blank frames before the video signal is actually queued up.. but such a device is generally very expensive in the video world and is called a "frame synchronizer" and would have driven the cost of a device from those years up.

Instead, the user starts the Video to generate frames which the encoder then starts to process to produce a stream, and then the VirtualDub program assumes the encoder is sending frames that it can preview.

For raw video capture its similar, but frames are always there from the moment video is presented.

Its the option to "automatically" command the DV camcorder that makes all of this "different" from a stream that is always running. The pros and cons of having complete control.