Difference between DirectShowSource & aviSource?

[romi7519]

What's the difference between DirectShowSource & aviSource?

The reason I ask this is because, I normally encode my DVD's to AVI using Lags (slow scripts).
Then I feed that to XviD encoder via MeGUI.
If I use aviSource(), I'm not asked to converttoyv12 but if I use DirectShowSource(), I am.

Why

[jagabo]

When using AVISource() AVISynth uses its own AVI file parser. DirectShowSource() uses Windows' DirectShow (the same libraries used by Windows Media Player) to parse and decode the file. For some reason one seems to be decoding to YV12 and the other to something else. You could use the Info() command to see what the colorspace is after DirectShowSource and AVISource().

I just tried opening a lagarith AVI with the two commands. DirectShowSource() decoded to RGB32, AVISource to YV12.

[romi7519]

Hmm, I think AVISource automatically decodes to whatever the decompresser accepts.

Cheers for the reply mate.

[towtruck]

Hello

I'm going to revive this thread instead of starting a new one. I asked some questions in a previous thread which bring me to this point (thanks to all who helped there).
https://forum.videohelp.com/topic329440.html

edDV wrote:
"The Panasonic DV codec converts incoming DV format to RGB by scaling 16 to 0 RGB black and 235 to RGB 255 white. At import any video in the 0-16 or 236-255 DV range is tossed (hard clipped). If you use AVIsynth to filter the 0-255 RGB, you are working on the clipped import."

Scott wrote:
"I'm having overall much better luck with the Cedocida DV codec (for VFW), though if you're using "DirectShowSource" in AVISynth, you ought to be just fine with the stock MS codec (no downloads/installs needed). "

So I tried DirectShowSource(). Everything worked fine, until I watched the finished DVD on the TV. The first movie was just fine, but the second of two hung-up (refused to continue) after about 5 seconds. If I skipped to the next chapter mark, it continued playing fine, but even if I FF'd in the first chapter, it always returned to the hang-up point. I finally fixed it by re-encoding only the second clip using avisource().

So now I've done some more reading about DirectShowSource, and a few questions remain.

Jugabo wrote:
When using AVISource() AVISynth uses its own AVI file parser.

However, aviSource clearly requires some sort of codec ( I used the panasonic codec I've been trying to get away from.) Which one is best?

In http://avisynth.org/mediawiki/DirectShowSource, it gives an example:
Opens a DV clip with the MS DV decoder:
DirectShowSource("F:\DVCodecs\Analysis\Ced_dv.avi" ) # MS-DV

So what decoder is used if I don't specify one??

As you can see, the wealth of information has left me bereft of answers. Any light that can be shed on this would be greatly appreciated. Basically, I want to get my DV into avisynth for encoding with HCEnc without any losses, and without producing any more coasters.

Thanks again.!

[jagabo]

Playing a video with DirectShow involves connecting several filters into a chain. Fo the video you'll typically have a file reader, an AVI splitter, video decompressor, maybe a colorspace converter, and finally the video render which puts the picture on the screen.

I know of three ways to determine what filter chain might be used for DirectShow:

1) Open the video file with GraphEdt. You'll see the filter chain:



2) Open the video with MPC. Use Play -> Filters to see the filters that are in use.

3) Open the file with GSpot. Use the Proposed Codec Solutions and Test buttons to see what filter chains work and what don't.

I don't think these are guaranteed to use exactly the same filter chain as AVISynth's DirectShowSource() but it's a start.