ADigitalMan's Guide to MPEG2/AC3 Editing — Page 11

I have a question on this (I know, right?)...

I like to use DGPulldown on my video files (23.976 -> 23.976) to strip pulldown flags on progressive content.  Womble otherwise reads the source as 29.97 and when it re-encodes the end pieces at cuts, it does so as 29.97i instead of 23.976p.  It makes your output variable frame rate.  So it's better to work in 23.976 and then add the flags back afterward.

I don't remember what order I used to do this in, but I'm working on a project now and ran GOP fixer first.  It said the video file had no errors.  Then I removed the pulldown flags and started editing but had some problems in my editor.

I rechecked it with GOP fixer. This time it found 18,424 time coder errors.

Can anyone explain this to me?

What do you use instead?

I know I'm one of the few still using Womble... and after this project probably not much longer.

I found another bug that you all might want to know about.

If you only let Womble re-encode audio at edit points (as opposed to fully re-encoding), you can get weird volume fluctuations at edit points.

Here's why: Stream copied ac3 leaves the dialog normalization level untouched.  Re-encoded segments have the normalization re-set to -31db (regardless of what you tell Womble to use as the audio source reference).

In the case of what I'm working with I get:

Main movie audio (-27db)---Cross fade area (-31db)---Deleted Scene(-31db)

So the audio of the main movie suddenly spikes 4db before fading out.

I'm going to see about dropping Womble a line about this, but in the mean time either allow full re-encoding of audio (ugh), or use VOBDNorm to rewrite all normalization of your completed edit (less ugh, just labor intensive).

ONE MORE thing.  I know there are those that claim normalization is ONLY applied when dynamic range compression is turned on (aka midnight mode), but this is NOT true.

Correctly built Dolby decoders use it as a reference to keep changing sources, features, etc. at a steady level so you aren't constantly fussing with your volume control.  (For example on Digital TV shows to commercials, etc. should have the normalization set so that the commercials aren't louder (in theory anyway)).

PowerDVD even simulates this (even when set to full unaltered dynamic range).  Generic software media players may not (so this might go unnoticed until too late).

I think Jetrell Fo is right, an expansion of this guide (or  new guide) for Vegas might be helpful.  Every time I look at the program I chicken out and go back to Mpeg Video Wizard.

Edit:  Heard from Womble.  Nothing helpful and an unreasonable request for files for them to examine.  Probably won't be fixed.

My recommendation for Mpeg Video Wizard editors who want to avoid this problem (it only occurs when your sources are Dolby Digital with dialog normalization set to anything besides -31db(?)):

1) Uncheck "re-encode the whole audio if any part needs re-encoding" when ready to export the final streams.  After building the final DVD use VOBDNorm on each VOB file to set the normalization where you'd like it.  (Or you can leave the re-encode option checked and suffer the slight quality hit.)

2) Get Sony Vegas.

FWIW, I ran into snags converting framerates so I could edit video files properly in Vegas that properly matched up with the audio.  I haven't solved these.  I'm sure the solution is simple but time is time.  ;-)

This guide is awesome and has tons of great info. Unfortunately I'm still having problems (skimmed over the forums to see if this was covered anywhere, but I didn't see anything)

I've been attempting to use Womble with no success - actually, more like no sound for some reason. I've checked the usual dumb things (like speakers not being on) but the audio on everything else on my computer seems fine. Just Womble has no audio (or there will a brief burst of sound, then nothing, but rarely occurring at the same spot).

I also attempted Vegas Move Maker, since I was having problems and have used ACID Pro in the past, but it kept running the video too fast. Although, I guess I should post more about that elsewhere)

My apologies for being so helpless with this stuff. It's probably something easy that I'm just not seeing. I admit that I'm a total newbie at this (is that the right word... newbie... or "noob"). I just have ideas for edits, but I'm worried that I'll never get to see them realized.

Anyway, thanks in advance!

Nevermind. After much trial & error (and the VOB2MPEG tool) I've more or less sorted out my issues with Womble.

Chewtobacca said:

Doctor M said:  If you only let Womble re-encode audio at edit points (as opposed to fully re-encoding), you can get weird volume fluctuations at edit points.

Here's why: Stream copied ac3 leaves the dialog normalization level untouched.  Re-encoded segments have the normalization re-set to -31db (regardless of what you tell Womble to use as the audio source reference).

Is this the only reason why the received wisdom amongst Womble users was to check the re-encode the whole audio if any part needs re-encoding option?  I used to run into problems with players choking on DVDs made from files exported from Womble, so I always used to check this option, along with Gop size compliance for DVD recording and use CRC protection.

Although I haven't tested the update, I'm told that the dial. norm. bug has been fixed.  Incredibly, they just didn't know about it.

Um, yeah.

It's why I was occasionally forced to use the full re-encode setting.

All the way back to my first fan edits, I remember previewed edit points within Womble sounding different than exported clips.
To avoid re-encoding I'd do a lot of trial and error test clips until it sounded right.

Anyone else have a reason to use the full re-encode setting besides volume fluctuations?

Yikes that's an in depth guide! Nice job putting it together it must've taken you a while. Thanks for sharing!

As I re-learn and re-tool my process for HD, I will likely post a new guide for all of you.  Vegas 11 has become a good friend of mine lately.

--ADM

Vegas 11 does a good job editing .ts files.  I've had success with a tool for the Mac called Foxit Video Converter that will convert the .m2ts stream to .ts.  I think DVDFab will do this on the PC itself but I've been running off an expired (read: free) version that has the conversion features disabled.

The rub so far has been that FoxIt downsamples (nicely, but downsamples nonetheless) the DTS audio to AC3.

The nice part is that you can import the .ts file and it map the video stream and the audio stream locked together with the audio channels assigned appropriately.

I'm using Vegas 11 Platinum, not Pro, so my output audio ends up being 5.1 PCM.  Not generally problematic, but a space hog on BD-25s.

So the debits so far are:

1) Downsampled Audio
2) Recompressed video.

It all looks and sounds really good, but isn't the perfect-as-original stuff I've done with Womble and standard-def.  I'm going to play with some other formats, such as converting to AVI instead of .TS and extracting the .DTS streams to WAV.  Then, it's just a matter of getting the seventh and eighth channels to map an encode correctly back into the BR.  Not sure if Vegas 11 handles that yet.  Documentation on Vegas 11 is really bad for such a nice commercial product, so I'm learning as I go.

Still wish I could find a way to do this for a living.  Both editing and teaching how to edit.

Could you do an edit in just Sony Vegas? If I already have a digital copy of a movie do I need anything else or can I just do it all in the one program?