FFDshow installation dialog

[terrypin]

While installing ffdshow I'm shown a window asking me to 'Select supported video codecs'. What exactly does that mean please? Why would I not want to check all boxes? Also, how do you interpret a check against the 'Uncompressed' box? IOW, how can an uncompressed file involve a codec at all?

This is what the window first looks like:

XVID
DivX 3
DivX 4
DivX 5
MS MPEG4v3
MS MPEG4v2
MS MPEG4v1
Windows Media Video 1/7 <--- Not checked
Windows Media Video 2/8 <--- Not checked
3IV2, 3IVX, RMP4, DM4V
MPEG 1 <--- Not checked
MPEG 2 <--- Not checked
H.263(+)
H.264, X264
MJPEG
DV
HuffYUV
CorePNG, MPNG
Uncompressed <--- Not checked

This is all a bit of a black art to me, so any advice would be much appreciated please.

--
Terry, West Sussex, UK

[Baldrick]

Why would I not want to check all boxes?

You might have another "better" decoder installed, but you can always select and deselect decoders after you have installed.

[celtic_druid]

Uncompresed allows ffdshow to be used in a graph for raw video (no decoder required) or after another decoder. Usefull since ffdshow is way more than a decoder. It offers a lot of filters, like deinterlacing, subtitles, etc.

[terrypin]

Thanks both, very helpful.

It's obviously a complex scene, and I'll have to get some practical experience before I really begin to understand it. With that in mind, I tentatively tried the ffdshow tool 'Video Decoder Configuration' to see how I would enable and disable entries. For example:
MPEG1 disabled
MPEG2 disabled
But when I click the drop down box (for either of them), expecting to see an 'enabled' option, I see instead
Libavcodec
Libmpeg2

How do I interpret that please? Which should I select to simply 'enable' ffdshow for the MPEG1 or MPEG2 types? And with these disabled, as they are at present, what is my PC doing when it encounters an MPEG1 or MPEG2 file?

--
Terry, West Sussex, UK

[celtic_druid]

Just means that both libmpeg2 and libavcodec can handle the decoding. Either setting will enable decoding, just in once case libmpeg2 is used and the other libavcodec.

With something disbled it simply means that ffdshow shouldn't be used in that case. As for what your PC is doing; either refusing to play the file because it can't generate a working graph or using another MPEG1/2 decoder if you have one installed (windows comes with an MPEG1 decoder).

[terrypin]

Thanks a lot celtic_druid, do appreciate your succinct help.

--
Terry, West Sussex, UK