Interleaving every frame or every 500 ms ??

Hi- I currently encode my movies in DivX Pro 5.0.2 with the AVISynth 2.06 + VirtualDub 1.4.10 method. How should I interleave the audio (it's the AC3 track extrated, then converted into WAV. Then, in VirtualDub, it's encoded in MP3 160 kbps & muxed). For my past 60 movies, I always used "Interleave audio every 500 ms". But I read almost everywhere that people interleave their audio every frame. Can someone explain me about this ? N.B. : the advantage of using 500 ms interleave is that it gives less overhead (i've calculated this...). Here's the Excel-based bitrate calculator i've written (in french) : A+

I don't know the reasons behind it, but on my system, interleaving audio every frame causes videos with MP3 audio to be choppy.

The standard (and recommended) setting for AC3 is "every two frames". You'll find this to be the default in GordianKnot. This always worked fine for me. bb

Well, regarding the fact that NanDub does not only store fracted multiples of AC3 frames as chunks, but even splits AC3 frames when splitting a movie, it really doesn't matter: Your files are messed up anyway, and without special code to take care of such bad files, no player could replay it properly. You should rewrite the whole file with AVI-Mux GUI. Since it's not nearly as complex as VDub/NDub, but merely a muxing tool, I had more time to take care of creating proper files :)

@alexnoe Nice tool which I had never seen yet. I just muxed and split a 2CD rip with AC3 using the deault interleave values you supply but playback is slightly jerky during pan & scans. Should we continue to use the interleave values we have been using in Vdub/Nandub with your utility? I couldn't find a readme or help file anywhere.

I can't reproduce this (to be more exact: I don't see any deterioration compared to NanDub output :) ). What CPU are you using? It might be possible that these shitty B-frame mess up the thing a bit. Does this effect also occur with "make rec lists" being switched off? Well, for replaying from CD, making "rec lists" was the initial idea why I made this tool...

just tested your prog the last hour and for me it works great. with nandub or vdub: interleave must be a multiple of 32ms to be smooth in slow panning scenes. :( with avimux: video is everytime smooth. :) tested on AMD+VIA+SoundBlasterLive, Intel+BX+SoundBlasterLive. (AC3 only, of course)

One AC3-Frame is btw 32ms long :) BTW

so does this mean that (lets say i use 75ms interleave) nandub just writes 75ms audio data every 75ms and your prog takes care of the frame size and use maybe 64ms audio the first interleave point and maybe 96ms for the next ? (sorry if this sounds completely stupid but i dont know anything about the avi file format :) )

It's a little bit more, but you mean the correct thing. However, my program only works on videoframe base, so that a value of 75ms would not be possible to set, unless you have a movie with a strange fps value ;) There's another issue with NanDub: If you use NanDub to split a file with AC3, then the AC3 stream will probably not begin with a AC3 frame, but with "the 2nd half" of a frame. AVI-Mux GUI will *not* process such streams. I haven't implemented handling of corrupted AC3/MP3 streams yet, and I won't be able to do that at the moment (semester has begun :rolleyes: )