Ok to interleave 96/96ms after GK default interleaving?

[Backflip]

I'm wondering if this decreases the quality of the AC3, but figure it doesn't. At the moment I'm using Gordian Knot at default output/interleaving settings, but after reading in the forums about interleaving at 96/96ms I've since started rejoining the AVI's I have, using VirtualDubMod, and saving them out with a preload of 96ms and interleaving every 96 ms. Direct Stream.

I also, just use Gordian Knot to save out a 1.36GB file (no splitting) with default interlaving now, then load it back into VirtualDubMod and save out again with 96/96ms. Direct Stream.

I've noticed an improvement in playback motion; it's much smoother, with 96/96ms esp. when using XviD as decoder.

Thanks :)

[Matthew]

I'm wondering if this decreases the quality of the AC3

I have no idea about the best interleaving settings, but the original audio/video streams remain unaltered by the process. Hence the quality is not reduced.

Rejoining can potentially be an issue due to bad xdub splits though. Sometimes a few bytes will be missing or duplicated at the join point due to a botched split, leading to a corrupt frame.

[Backflip]

Phew, thanks for the confirmation about the AC3 :)

How do you check for a corrupt frame at the join? Can you see this corruption simply by watching the file using XviD as the decoder? I'm guessing MPlayer won't notice it, but I would certainly like to know the file is fine no matter what is used to decode it.

[Matthew]

Oops, I didn't make that clear. The video will be fine, it's the audio that may have a corrupt frame. As a practical matter it probably isn't a real problem (rips with a positive audio delay have junk data at the beginning, for example), but it could be an annoyance if you ever converted an avi to DVD (which is something I do rather a lot).

You can check easy enough by extracting the audio from the joined avi and running it through BeSplit/BeSpliced, for example, it'll report a stream error if it finds any corrupt frames.

[Backflip]

Thanks for the info :)

One last thing (think it might be the last). I think I might have been thrown a curve ball, maybe someone who interleaves at 96/96ms might be able to help me.

I finally got around to encoding Bride & Prejudice:

1. Encode DVD to 2x700MB/AC3 (448) using default interleaving. No splitting.
2. Open 1.37GB file in VirtualDubMod
3. Set Interleaving to Preload 96 and Interleave audio every 96ms (96/96ms)
4. Manually save out segments of around 700MB (cut at keyframes)

Now when I loaded this into GSpot (latest beta) the following for the first 700MB part:
Interleave: 96 ms (2.4 v.frames), preload=96

However, second 700MB part is:
Interleave: 95 ms (2.4 v.frames), preload=96

I find that quite confusing^. Why is it like that???

If I let VirtualDubMod do its autosplitting it gives the same result (as well as a 7MB 3 file).

I haven't tried 64/64ms, but I'll see if that's a better result now.

[Matthew]

I suspect that relates to the fact that when you split the avi, you end up with part of an AC3 frame at the end of the first avi and the rest of that frame at the beginning of the second avi. [Although like I said above, sometimes a few bytes are missing, and sometimes they are duplicated].

This partial frame at the beginning of the second avi may throw GSpot off. You could also try YAAI.

[Backflip]

I gave YAAI a go. Which part in YAAI's statistics should I be looking for which relate to interleaving?

My main goal, and purpose, of finding out why files are sometimes outputed with interleaving indicated to be different (in GSpot) to the 64/64 or 96/96 VirtualDubMod saved out as is so I can rule out something I've done wrong. From what I understand it's normal for GSpot to indicate some statistics incorrectly, or the stat's it is indicating are correct, but the way in which VirtualDubMod saved out had to be like that, and is ok.

Thanks for answering my previous questions Matthew :)