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 LAMEMP3 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:
Quote:AVI: Stream 0 (video) has a non-zero start position of 2 samples (+67ms). VirtualDub does not currently support a non-zero start time and the stream will be interpreted as starting from zero.
This happened with the first video too, though, so I think it's probably not important (but I could be wrong).
_ 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?)
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?
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.
Originally posted by Ander: 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?)
