Avi & Yv12

[scmccarthy]

I want to resize an existing AVI from a DAP of 2.4 to 2.37 (672x280 --> 720x304) because as I watched it I decided that I need to bring is closer to the standard 2.35 DAP. The reisize seems to soften and smooth the picture, rather than degrade it.

But, I don't think there is a way to stay in the YV12 color space to do the conversion, that only works when you are reading from an mpeg2 source as I understand it.

My question is: am I wrong about that? Or is there any way I can stay in YV12? Or generally speaking: What is the best way to do the resize with VirtualDubMod and Avisynth?

I do so much ripping with DVDs directly that I do not know how to do anything else. Some of you will want to point out that I can read the AviSynth Documentation, and you are right, but don't bother, because that probably would not answer the YV12 color space question. I vaguely remember that there is more that one way to read an AVI file, What are the pros and cons of the different ways? (I almost said 'best way', but I caught myself, 'best' is against forum rules for good reason. Someone had to write the code for each way AviSynth can read a file; if one of the ways didn't have anything to recommend it over the other ways, he would not have included it.)

OK, so that's a long enough question. Thanks for listening.

Stephen

[Wilbert]

My question is: am I wrong about that? Or is there any way I can stay in YV12? Or generally speaking: What is the best way to do the resize with VirtualDubMod and Avisynth?
How is the avi coded? If it's DivX4/5 or XviD (they output YV12) just open it in AviSynth

AviSource()
BecubicResize(720, 340)

Open it in vdubmod -> fast recompres -> DivX/XviD.

[scmccarthy]

Yes, thank you, it is divx, that makes it mpeg4, I am not used to making an mpeg4 --> mpeg4 conversion instead of mpeg2 --> mpeg4. I was not sure if I could still use fast recompress with AviSource as I do with Mpeg2Source.

So, thanks,

Stephen

[sh0dan]

... and if it is DivX 3, use ffvfw as decoder to open it as YV12.

[scmccarthy]

I can't find any information how to open an AVI file in VirtualDubMod, using FFVFW as a decoder. perhaps I don't have a new enough version.

Stephen

[Kurosu]

Originally posted by Wilbert
How is the avi coded? If it's DivX4/5 or XviD (they output YV12) just open it in AviSynth

AviSource()
BecubicResize(720, 340)
Although there's no real need to bring it further as scmccarthy had a sufficient reply, in case of DivX3 content, here are the needed steps:
- install DivX5.xx, ffdshow or probably XviD, provided the later handles DivX3 content
- consider if you need the source to go through the codec' post-processing, and therefore maybe disable it
- use directshowsource() when encoding and avisource().ConvertToYV12() when testing, as DSsource can't skip fast.

[Didée]

Originally posted by scmccarthy
I want to resize an existing AVI from a DAP of 2.4 to 2.37 (672x280 --> 720x304) because as I watched it I decided that I need to bring is closer to the standard 2.35 DAP.
Does it really make sense to re-encode the whole thing only for that little bit of AR correction? Me for sure, I'd go for on-the fly AR correction, e.g. through ffdshow, or through ZoomPlayer, or put it into MKV and set the correct AR there.
But perhaps you have some requirements I'm not aware of.

- Didée

[sh0dan]

Originally posted by scmccarthy
I can't find any information how to open an AVI file in VirtualDubMod, using FFVFW as a decoder. perhaps I don't have a new enough version.

Stephen

Go into the ffvfw configuration. Go to the "Decoding" tab and select "DivX3".