Codec drop-down lists?

[terrypin]

Can anyone explain how the list of codecs that is offered by drop-down in a program gets constructed please? Taking CamStudio and VirtualDub, for example, I found 19 and 28 entries respectively. I'd sort of expected them to be identical, but plainly that was a daft assumption.

Each time a program runs, does it examine all installed codecs on my PC at present and choose those that are relevant? Or what?

In VirtualDub but not CamStudio

(Uncompressed RGB/YCbCr)
Converts YV12, I420, YUY2, UYVY to RGB24
Converts YV12, I420, YUY2, UYVY to RGB24
Microsoft H.261 Video Codec
Microsoft H.263 Video Codec
Microsoft RLE
Huffyuv v2.1.1
Intel Indeo(R) Video R3.2
Fraps Video Decompressor

(BTW, I see that VirtualDub has a couple of duplicate entries. I posted earlier about that arising in CamStudio.)

--
Terry, East Grinstead, UK

[guns1inger]

Virtualdub only supports VFW codecs, so it ignores any directshow codecs. Similarly, some programs can only use directshow codecs, and so will ignore others.

Duplicate entries could be based on slight variations in version or attributes.

I am not sure if it is the same for the older vfw codecs, but directshow codecs are all registered in the registry. The programs will generate their list when they launch based on this.

[terrypin]

Thanks, I'll try to find them in the XP Pro registry.

--
Terry, East Grinstead, UK

[Safesurfer]

Try Filmerit, it will show you all of the codecs on your system.

[jagabo]

I don't know about CamStudio, but some programs do not use system installed codecs but rather their own built in encoders.