Mapping Values in the Registry

As discussed elsewhere, the meaning of some of the camera information encoded in the DV data may be different than that according to the official DV specification. The Enosoft Enhanced DV Decoder allows the encoded information to be mapped to custom values via entries stored in the computer's registry. Currently, this is available for the shutter speed and the electronic gain. Mapping can be enabled and disabled using the Configuration Utility.

All of the settings are stored in the following registry key:

HKEY_CURRENT_USER\Software\Enosoft\{B65D9838-0B54-11DA-B692-001150776A3C}\1.5\Config

Two subkeys exist - Gain Code Maps and Shutter Speed Maps, labeled A below:

Each of these subkeys contains a string value called ActiveMapName (B) and at least one additional string value (C). The ActiveMapName must contain the name of one of the other strings. In this case, the ActiveMapName is "Standard" and is the same as the name of the string marked C.

The decoder will read the value of B and use the mapping that it points to (D). The contents of B or D are easily edited within the registry editor (regedit). Simply double-click on the name (e.g., "Standard" in the name column) to display the Edit String dialog box:

and edit the string ("Value data") directly.

Gain Code Maps

The DV specification requires that the gain value be encoded as a number from 0 to 15, inclusive. The string value contains 16 items, each separated by a comma. The standard map is:

-,0,3,6,9,12,15,18,21,24,27,30,33,36,-,-

For camcorders that support -3dB gain, you could change the string to:

-3,0,3,6,9,12,15,18,21,24,27,30,33,36,-,-

Shutter Speed Maps

Mapping shutter speeds is slightly different that for gain codes. There are more than 32,000 possible shutter speed values and mapping them directly in the same manner as the gain code would require a string with more than 32,000 entries. Most camcorders will only support a small number of shutter speeds (e.g., 20) and the mapping uses pairs of values. The value that you would like displayed is first, followed by the value that is displayed according to the DV specification. For example, for many Sony NTSC DV devices, the following map applies:

4,4,7,8,15,15,30,30,60,60,91,90,100,100,129,125,183,180,258,250,366,350,524,500,749,725,1049,1000,1573,1500,2248,2000,3147,3000,5245,4000,7867,6000,15734,10000

In the registry, this map is called SonyNTSC.

It is recommended that shutter speed mapping is disabled at first in order to find out how a particular device compares to the DV specification. If the values displayed by the decoder match those according to the device (e.g., the device's own display or the instruction manual), no further action is necessary. However, if there is a mismatch and you would like to have the decoder match the device, you will need to create a new map (unless the SonyNTSC map is appropriate).

To create a new map, right-click on Shutter Speed Maps and choose New/String Value:

and change the default name (e.g., New Value #1) to something more meaningful (e.g., MyOtherCamera):

Then, double-click on the new entry's name to edit the string:

The string is initially empty. Create the new map as required and then click OK. Finally, change the ActiveMapName string to MyOtherCamera:

When Shutter Speed Mapping is enabled, if the necessary pair of numbers does not exist in the map string, the decoder will display an @ symbol to indicate that the mapping was unsuccessful.

Hint - The quickest way to create a new map is to connect the device in camera mode to the computer and (for Windows XP) open the "folder" for it from My Computer. You should see the live feed from the camcorder on the computer's display, together with the DV decoder's information. Configure the camcorder to display the shutter speed on its display (or analog output). Disable the shutter speed mapping using the Configuration Utility. Open regedit and create a new map as discussed above. Cycle through the camcorder's shutter speeds and, for each speed, enter "<a>,<b>," without the quotation marks, where <a> is the value displayed by the decoder and <b> is the value displayed by the camcorder. For the very last entry, omit the second comma. Once complete, close the Edit String dialog box and follow the remaining instructions above. Enable the shutter speed mapping. For the new mapping to come into effect, close the live feed folder view and re-open it.

If you create a new map, please consider posting it to the Enosoft Users Group including the name of the device. This will greatly assist other users and allow Enosoft to add more entries in future updates. Thank you!

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Last Updated on Thursday, May 25, 2006.

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