2 pass encoding in VirtualDub question

[jrpeacey]

I set up VDub for 2 pass encoding. It got through the 1st pass, creating "firstpass.avi" then the program failed.
I have divx.log and mvinfo.bin in my root directory, and the program knows where to look for them. But if I restart VDub on the 2nd pass, how do I tell it where the results of the first pass are (firstpass.avi) or do I need to? What is the funtion of the AVI output file from the first pass?

Thanks,

[Acaila]

Did VDub fail at the end of the first pass, or at the beginning of the second pass? If it failed at the end of the first pass then your logfile will be corrupt and you'll have to redo the first pass. If VDub failed on the second pass you should be able to run a normal second pass again as decribed in the guides.

how do I tell it where the results of the first pass are (firstpass.avi)

In the codec settings page in VDub you have set the place where the first pass logfile should be saved. The second pass will use the file in that location, so if you didn't run any other encodes it should still be a valid location.
When maunally setting up the second pass you have to make sure you use all the same settings as you used for the first pass (this can sometimes be hard to remember if there is a long time between the first and second pass).

What is the funtion of the AVI output file from the first pass?

There is no real function. During the first pass the codec needs to output certain streams to calculate everything correctly, and this is what is left over when it's done. This avi file is just a dummy file and can be safely deleted when the first pass has finished, only the logfiles are relevant.
I still don't understand why DXN didn't make it so that avi file gets deleted automatically when the first pass has finished to avoid confusion...

[ftack]

Just a little question on the sideline regarding the AVI file created on the first pass. I see that people sometimes use different names for the AVI file of the first pass and that of the second pass. It is even in some guides. Is there a need for that? I simply provide the same AVI filename for the second pass so DivX happily overwrites it during the second pass and I do not need to worry about DivX Networks implementing a delete after the first encode.

[theReal]

how do I tell it where the results of the first pass are Regarding this question it seems to me like you haven't configured the codec at all?
You need to go to the codec property tab, select bitrate and all that stuff and also select "2-pass, first pass". Then you save this as a batch-job, go to the codec properties again and select "2-pass, second pass", also save it as a batch job, then select job control and start the batch jobs.

[Acaila]

@ftack:

That's exactly what I do too.

But if you're just starting out in the encoding business and don't know what's what yet, it can be confusing I think. I've seen enough newbies post questions like "Why does the avi file I created give a black screen when I try to play it back?" or "Why is my avi file only 5 MB when I used a bitrate of 1000?" or something of that nature.

Since it's a useless file anyway, why not have it deleted automatically right after the encode to avoid any kind of confusion? Can't be that hard.

[ftack]

| Since it's a useless file anyway, why not have it deleted
| automatically right after the encode to avoid any kind
| of confusion? Can't be that hard

It could be harder than we imagine. The codec is called from within any video editing application. What the codec does is compressing the video stream, but it is the video application, and not the codec, that controls opening and closing the AVI container file and writing the compressed video stream to it. So that may be the reason why DivX network is not supposed to implement deleting the avi file from a first pass.