XviD encoding problem

Hi guys,

I'd really appreciate your help with this...

I'm trying to copy our family videos from Video8 tape to XviD. Using our capture card, I saved the video to uncompressed AVI (YUY2). Then, using VirtualDub 1.8.0, XviD 1.2.1, and LAME MP3 v3.82, I did a successful two-pass encode, using XviD's default settings.

I've just tried encoding a 2nd video---but for some reason, XviD stops in its tracks (no pun intended) at the end of the 1st pass, right at 100%, and doesn't exit. (VirtualDub's Job Control thinks it's still running.)

Before my 2nd try, I ran VirtualDub's "Scan video stream for errors" tool to mask out bad frames, then tried the conversion again---same result. Does anyone have an idea why this may be happening?

I do get one error message when I open the AVI in VirtualDub:

This happened with the first video too, though, so I think it's probably not important (but I could be wrong).

BTW, I'm also using these filters in VirtualDub:

_ Smart Deinterlace (3rd-party)

_ Resize (native), to crop out the image's bottom 16 px. to remove a bar of noise (yes, the remaining image's dimensions are divisible by 16)

Should I be applying the filters to both passes, or is it okay to apply them only to pass 2? Or does it matter? (Are they just ignored on the 1st pass?)

Thanks for your help! -- Ander

 

I thought of one more thing that may be affecting this:

Unlike the first video, I'm setting an end-point in this one (to omit a bunch of blank space). Could this be causing the problem? In VirtualDub, I'm just setting the end-point at the last frame that has an image... Do I need to be setting it at a particular frame to keep the video compatible with XviD?

 

Hi again,

Okay, I've solved the problem, sort of:

I waited for XviD to crash at the end of the 1st pass, then exited it and VirtualDub manually. I deleted VirtualDub's job file, then re-ran VD and did the 2nd pass separately. Despite the crash, XviD seems to have saved the 1st-pass data properly, because the 2nd pass finished properly and the resulting video looks fine. It's still odd that it stopped like that, though.

Cheers, Ander

 

Unless you have a specific size need, there is no reason to use 2 pass. Use 1 pass with a low quantizer... try 2.

 

Really! So you get best image quality that way?

 

Well try using Avidemux instead of Vdub for your 2 pass encodes, maybe it won't hang.

Xvid 2 pass encoding is usually used to hit a predetermined size. The first pass figures out how to distribute quality based on meeting the size (like the common 700MB). If you are not concerned about exact size a one pass constant quantizer setting with a higher quality quantizer (a lower number) should produce a better result. It tends to be more wasteful of 'bits' (even parts that don't need it are using a high quality setting), hence a larger file size. Try a one pass, Quantizer set to 2 and see how it looks.

 

Thanks very much for the suggestion. Single-pass with "Target quantizer = 2" works great, and since I'm burning to DVD-R anyway, size doesn't matter. (Heh, that's a refreshing change of philosophy in several ways, ain't it?)

Cheers, ander