VirtualDub -> Handbrake m4v, audio settings?

[milltone blabbit]

Hi all,

I've been trying to create opera vids from VOB to iPod video with burned-in subtitles. I can make titles in VirtualDub w/ VobSub, and I save the results with HuffyYUV compression and (I think) straight PCM audio.

However, upon converting w/ Handbrake I get audio problems - sometimes there is a rapid, rhythmic distortion (like a 30ms cycle) of the sound that to me sounds like the audio is being "stretched" badly.

Does anybody have recommended settings for either VDub or Handbrake for fool-proof audio?

[poisondeathray]

Are the problems caused by handbrake or vdub? ie. Is the export from vdub ok? or is the problem caused earlier in your workflow (e.g. maybe not properly decrypted vob)

[milltone blabbit]

Is the export from vdub ok?

Yes, the avi file from vdub plays fine. My mindset right now is that "there is something about it that Handbrake doesn't like" so I imagine it can be solved on the vdub end, but I dunno.

[poisondeathray]

You could try another front end GUI for export to ipod, eg. ripbot264, xvid4psp, megui. It might be an issue with handbrake or that particular build

I doubt the issue is with vdub's export format; you could try another format in vdub, like lagarith (I can't see the PCM audio being the cause of the issue)

You might test on a short 1min clip, to minimize testing time wasted on trial & error.

[milltone blabbit]

You might test on a short 1min clip, to minimize testing time wasted on trial & error.

This was good advice! I started working on a collection of short music videos and ran them through vdub. I quickly found a VOB that produced that effect (since it doesn't happen with ALL files, just some.)

I varied two audio settings in VirtualDub: "full processing" vs. "direct stream copying," and "interleave"

(audio stream in the VOB is stereo AAC, btw. I think my opera DVDs are PCM, so we'll see if this translates.)

full processing with interleaving: produced the effect I was talking about. Hearing it again I'd describe it as a constant "flutter"

full processing with no interleaving: produced a little audio glitch every second or so

direct stream with interleaving: unreadable? apparently it crashed handbrake.

direct stream, no interleaving: worked!

I had previously stuck with the interleaving on because, in my old experiments using Quicktime to convert I had lots of sync issues. However, the sample track with direct stream copy and no interleaving also had perfect sync throughout.

[milltone blabbit]

Well, I had hoped I had it fixed, but not quite. I had a little more work to do.

Writing files from vdub with "direct stream copy" and no interleaving of audio worked sometimes, but

1) Sometimes I got a weird bug in the final m4v, wherein the video would run to its conclusion (with the appropriate audio), but then the audio would start all over again and play to a black screen.

2) Sometimes HandbrakeCLI would be unable to read the file. (It would search for "title 1" and fail.)

The solution? Avimux. Apparently avimux could take the vdub file and interleave the AAC content correctly so that handbrake would read the file. So far the results look perfect.