AviSynth - Small Gray Box!?

[blackz0r]

Hey all,

I've run into a problem with AviSynth (or one of the plugins, or... something). Let me setup the scenario:

I had a UK friend of mine capture a TV episode for me with his DVD recorder. The source, I believe, was PAL 576i. His recorder auto-converted to progressive. He shipped the output disc to me, and it is now in my possession.

I popped the disc in my drive and created an image with DVD Decrypter. I then mounted the image, loaded the VOB files up in DGIndex, and created a .d2v file. With the output, I created an AVS script that looks like this:

MPEG2Source("test.d2v")
MPASource("test T01 DELAY 62ms.mpa")

When I load this in VirtualDub to make my edits, all I get for video is a 4px by 4px gray box. The audio functions as expected. MPC and other players exhibit the same behavior.

I'm running the latest non-development versions of all software involved, including AviSynth, the MPEG2 decoder plugin, DGIndex, VirtualDub, and MPC.

What could be wrong here? And, more importantly, what can I do to fix it?

[daamon]

Try using VirtualDubMod or VirtualDub-MPEG2 - both of those are equipped to work with MPEGs, whereas the original VirtualDub isn't.

I don't know if this will solve the problem, but it's worth a try.

I've never used AviSynth at all, let alone with any of the VirtualDubs - so it's only a guess...

Good luck.

[Guest34343]

Hi, I'm the author of DGIndex.

Use Chopper XP to cut a fragment of the VOB (say 50 meg). Put it on a free upload site and then notify me by PM. I'll figure it out for you.

One thing to try. Instead of making an image and mounting it, just rip the VOBs to your hard drive and open them in DGIndex.

[FulciLives]

Make sure that you are pointing to the DGDecode.dll file. For instance ...

LoadPlugin("C:\DVDFiles\DGMPGDec\DGDecode.dll")
MPEG2Source("C:\MYDVDFOLDER\test.d2v")

Also since you want to edit I highly suggest you convert the audio to a 16-bit 48k 2 channel (mono or stereo) PCM WAV audio file. That can be done with a variety of programs.

So let us say that you create the PCM WAV and call it test.wav

Here is how your script would look:

LoadPlugin("C:\DVDFiles\DGMPGDec\DGDecode.dll")
LoadPlugin("C:\COPY_DVD\decomb\decomb521.dll")
LoadPlugin("C:\Program Files\AutoGK\filters\RemoveGrainSSE3.dll")
video=MPEG2Source("C:\MYDVDFOLDER\test.d2v")
audio=WavSource("C:\MYDVDFOLDER\test.wav")
Audiodub(video,audio)

You are now ready to edit in VirtualDubMod.

Here is my guide ---> CLICK HERE

This guide covers the use of a "video noise filter" called Convolutioin3D but it is for an interlaced source. So you can ignore all of that stuff. The other part of the guide covers editing with VirtualDubMod and how to input the edits into your AviSynth script.

So a sample script might look like this:

LoadPlugin("C:\DVDFiles\DGMPGDec\DGDecode.dll")
LoadPlugin("C:\COPY_DVD\decomb\decomb521.dll")
LoadPlugin("C:\Program Files\AutoGK\filters\RemoveGrainSSE3.dll")
video=MPEG2Source("C:\MYDVDFOLDER\test.d2v")
audio=WavSource("C:\MYDVDFOLDER\test.wav")
Audiodub(video,audio)
Trim(195,42620)

Now assuming you want to convert to NTSC you would do this ...

LoadPlugin("C:\DVDFiles\DGMPGDec\DGDecode.dll")
LoadPlugin("C:\COPY_DVD\decomb\decomb521.dll")
LoadPlugin("C:\Program Files\AutoGK\filters\RemoveGrainSSE3.dll")
video=MPEG2Source("C:\MYDVDFOLDER\test.d2v")
audio=WavSource("C:\MYDVDFOLDER\test.wav")
Audiodub(video,audio)
Trim(195,42620)
LanczosResize(720,480)

That is assuming the source is 720x576 and is progressive.

Now simply encode a hybrid ... using the NTSC resolution of 720x480 but the PAL frame rate of 25fps. Then run the resulting MPEG-2 file through DGPulldown to make it fully NTSC compliant.

In the end you can convert the PCM WAV audio file back to another more compressed DVD friendly format like the AC-3 format.

- John "FulciLives" Coleman

[Guest34343]

His script is wrong.

He had:

mpeg2source()
mpasource()

It should be

vid=mpeg2source()
aud=mpasource()
audiodub(vid,aud)

His script was throwing away the video. Implicit last and all that.

[FulciLives]

@neuron2

This may be an "odd" time to bring this up but I've always had a question about AVI2DVF/DGIndex.

How come it seems that every PAL DVD always shows up as INTERLACED when in my experience most are PROGRESSIVE ... at least that is what my eyes tell me (at least with most of the PAL DVD releases I have seen).

I never could figure that out ...

- John "FulciLives" Coleman

[Guest34343]

Hi John!

That's a good question. I wish I knew the answer so I could give it to you.

I'm sure you know that the encoding method used by the MPEG2 encoder can be set as per-frame (progressive) or per-field (interlaced), and that there is nothing to force that it matches the actual content of the video. My guess is that the negative consequences of encoding progressive content as interlaced (small file size penalty) is less serious than the consequences of encoding interlaced content as progressive (big quality loss for the same bitrate). So the content authors just set their encoders for interlaced and don't think about it. Still, if you know you have progressive content, it doesn't take a rocket scientist to think of using progressive encoding. Maybe the authors are artsy types that don't know this technical stuff and just accept the default settings of their MPEG encoders.