Exception Error with subtract and histogram

[signal]

I originally posted a question in the usage forum for trying to find the best way to show the noise captured in a clip for demonstration purposes.

I created a dvd with colorbars (generated by avisynth colorbars) and then captured a Huffyuv clip with vdub.

But a problem has come up and thought this was probably the better place to discuss it.

When trying to use subtract or historgram I end up with the following error (using AVISynth 2.57)
CAVIStreamSynth: System exception - Access Violation at 0x0, reading from 0x0

The avisynth scripts used are:clip = avisource("d:\cb4sub.avi")
subtract(clip.trim(1,0),clip)
andavisource("d:\cb4sub.avi").histogram(mode="luma")

When using subtract, the error pretty much occurs right away.
With histogram, I did get one successful playback however subsequent playbacks the error either shows up right away or after a few seconds.

It was pointed out that possibly excessive seeking maybe crashing the Huffyuv codec.

[update] In trying a couple of other codecs (including lagarith) things seem better but still eventually get the exception error. It appears that the functions are still struggling with this clip no matter what codec I use.

Sample Clip: cb4sub.avi (47MB Huffyuv) (http://64.202.175.38/examples/cb4sub.avi)

Is there some other processing that needs to occur before feeding subtract or histogram or is there indeed something not quite right here?

[squid_80]

I downloaded the file and can't recreate any problem (using avisynth 2.5.7 31/12/06). But what I did notice is the file can't be decoded correctly by ordinary huffyuv, only ffdshow which would seem to indicate it was captured using ffdshow with adaptive huffman tables turned on. Have you tried updating ffdshow?

[signal]

Very weird, this is a fresh XP install and I don't have ffdshow installed.

It was captured with VDub 1.7.2, Huffy 2.1.1, and an Osprey 210 with their latest drivers. Options in VDub were at default.
Colorspace selected in the Osprey is YUY2.

Playback of the AVI in MPC works fine and don't see ffdshow showing up in graphedit.

It also happens with lagarith so wondering if Vdub or the colorspace selected is coming into play here. I'll try Vdub 1.6.19 and an alternate colorspace.

BTW - AVIsynth 2.56 pretty much croaks on this right away but from what your saying that's no surprise.

[squid_80]

Whoops, my mistake - slightly different versions of huffyuv detect interlaced encoded files differently and my version was misidentifying it. Disregard what I said about ffdshow, but I still can't get it to crash at all.

[signal]

I just tried it on a different system and same thing was happening.

With Vdub I did a direct stream copy with no audio and saved as "Old AVI Format" and it seems to work.

Tried the new file on the original system and seems to be ok.

Tried the original clip on a third system without audio hardware (yet) and it worked.

This was for both subtract and histogram.

I can reproduce the problem with the original clip on the first two systems so for some weird reason either the audio or avi format seemed to influence the problem on these two systems.

Thanks for checking on this though.

[neuron2]

No problems here with it:

VirtualDub 1.7.0
HUFYUV 2.1.1
Avisynth 2.5.7
Athlon 64 FX-55

[signal]

Yea, I'm not sure why it wouldn't work on two systems but did on a third but the "fix" I did in my last post seems to work fine.

Update: Got a tip to use audio=false on avisource and that works as well.

So something screwball with the audio on my systems was the reason.
Using Realtek HD with the R170 drivers on both.

Regardless, sorry to trouble you all and thanks for the help.

[squid_80]

I noticed the audio was 96000Hz but it didn't occur to me that it might be the problem.