How to avoid the colorspace conversions in AviSynth Script?

[LisaB]

My AviSynth Script is:

AVISource("F:\Video\Clip.avi")
ConvertToYUY2()
Telecide()
Trim(0,77965)
FadeOut(70)
BicubicResize(320,526,0,0.6,1,0,718,480)
AddBorders(16,25,16,25)
AssumeFPS(25.000, true)
ConvertToRGB24()

I have to convert to RGB, since I'm using TMPGEnc to encode. And Telecide only works with YV12 or YUY2 (version for 2.5). But for some reason if I do:

AVISource("F:\Video\Clip.avi",true,"YV12")

or

AVISource("F:\Video\Clip.avi",true,"YUY2")

I get an error that the decompressor can't produce the desired output!

Now, I load the avi in VDub, and it says the decompressor is:
DivX MPEG-4 Low-Motion

Is there any way around having to do 2 colorspace conversions?

[CogoSWSDS]

Yes there is a way to avoid two color space conversions...Don't convert it to RGB24 with your script. I use AVISynth and TMPGEnc and feed TMPGEnc YUY2 all the time and it handles it just fine...

CogoSWSDS

[adam]

Is there any way around having to do 2 colorspace conversions?

If you are set on doing your deinterlacing with this filter, than I don't see how you can avoid the double colorspace conversion. Your source is clearly RGB so there is no way to avoid the conversion to YUV, and once this has happened, TMPGenc can only accept RGB input, so again your stuck.

If possible, try to find a deinterlacing filter that accepts RGB input, I'm sure there are plenty, and then just keep it RGB all the way.

CogoSWSDS, if you don't convert to RGB in avisynth it still gets done by VFAPI when it enters TMPGenc, it just takes longer and overall isn't as stable.

With RGB input, a filter which only supports YUV, and an encoder which only supports RGB, I don't see how you can avoid the double color space conversions.

[LisaB]

Well, it seems that it is less an issue that my source "is clearly RGB", but rather that the decompressor can not provide any other kind of output. Does the encoded file itself have an associated colorspace, or does it only become associated with a particular colorspace once it has been decoded by the decompressor? I don't know...

The documentation for AVISource says that it will first ask the decompressor for YV12, and then for YUY2, and then for RGB32....I would think that if the encoded data had a colorspace, that AVISource would want to preferentially retrieve the data using that colorspace, rather than simply following some set order....That is why I ask the question in the previous paragraph.

I think that other decompressors (like Divx Pro 5) can provide more than one type of output. Is there a way I could get Divx Pro to be the decompressor for this file (by changing 4c code?)...because I know that Divx Pro supports YUY2, and maybe even YV12.

Also, check out: http://www.avisynth.org/index.php?page=Convert
They say that I can configure HuffyUV to do YUY2 decoding, and then never have to use ConvertToRGB again! However, I can't get this to work, even doing the registry change and all...

[Wilbert]

Now, I load the avi in VDub, and it says the decompressor is:
DivX MPEG-4 Low-Motion

Like you said DivX3 outputs to RGB32 (while it is stored internally as YV12). ffvfw can decompress it:
http://forum.doom9.org/showthread.php?s=&threadid=55207&highlight=ffvfw+rgb32

They say that I can configure HuffyUV to do YUY2 decoding, and then never have to use ConvertToRGB again! However, I can't get this to work, even doing the registry change and all...

DivX5/XviD decompresses YV12, so you need a YV12 decoder (like ffvfw, DivX5 or a recent version of XviD).