No sound when authoring vob file using tmpegenc

[Dwight Flynn]

I have a wedding dvd that I am trying to edit. I converted the vob fies to mpeg using tmpegenc xpress. The resulting mpeg video files plays fine but the audio does not play. When I use g-spot or avicodec to view the codec info they tell me that the mpeg 1 layer 2 audio is present, so I do not know why it is not playing. Help?

[Douglas Spotted Eagle]

What are you editing with? In Vegas for instance, there is no point in converting the vob, just drop it on the timeline. If the audio isn't AC3, it reads. Same with Ulead.
I don't know TMPEGEnc, I use other encoding tools, but this is pretty straight forward.
Does the audio play OK in a media player/DVD player from the hard drive? Is there a setting in TMPEGEnc that allows audio to be stripped?

[Emre Safak]

What does GSpot say when you render it? Maybe your codecs are messed up.

[David Ennis]

Dwight,

I just tried making an mpeg of a three minute segment from one of my VOBs using all the defaults in TMPGEnc Express and the audio was fine (as played with WinDVD).

The VOB had been created with TMPGEnc DVD Author.

[Dwight Flynn]

I dropped it into vegas with no luck (also no luck with windows media or windvd). G-spot reads MainConcept MPEG Splitter --> ffdshow Audio Decoder --> AC3Filter --> for audio. The original vobs play just fine, sound and all. I don't know what type of audio codec is in the vob and I am at a lost as to finding out what is happening. Help....?

[Dwight Flynn]

Spot, TMPEGEnc does have an option to create a separate audio file, and one for a combined file (which is what I chose). I am going to try this again, but this time keeping them separate (though I am not confident it will work). whether or not this works, I would like other options for pro (with ease of use) audio stripping tools.

[Emre Safak]

So you have an AC3 (Dolby Digital) stream, seeing as it is being routed to AC3Filter. Try downloading the newest ffdshow and configure the audio options (it's in the program's folder)

[Douglas Spotted Eagle]

G-spot reads MainConcept MPEG Splitter --> ffdshow Audio Decoder --> AC3Filter --> for audio.

This tells me that you have AC3, which is what I was speaking of in my first response.
BeSweet has an AC3 to wav converter, and there are others as well. BeSweet worked really nicely for me in the one time I've had to do this. I'm pretty staunch anti-AC3 conversion. Not only is it a violation of Dolby's terms of use, but it's also commonly used by pirates. I think everybody knows where I stand on piracy.

[Dwight Flynn]

Ok, spot maybe I need to start from the beginning (since this is not my greatest area of concentration). Is ac3 a codec or not, and if so, are you saying that it it is owned by dolby (I know this question seem simplistic but I really do need to know). And for future reference is there a comparable less legalistic codec I can ask for or use (even dare I say a free one), when I need to do audio video modifications.

Thanks

[Dwight Flynn]

Spot, BTW can you recommend a good book that I can use to get a solid grounding in audio codecs (one that takes into account that I am a beginner)?

Thanks

[Douglas Spotted Eagle]

Dolby owns AC3. (Audio Compression, 3rd Generation)
Only Dolby can license companies to utilize the codec. AC3 was NEVER designed to be edited. It's like MP3 to an extent, that carries metadata to talk to a playback device.Dolby specifically forbids the transcoding of AC3 files, but there are several tools that can decode and edit AC3.

The only time AC3 needs to be edited (IMO) is if:
1. You messed up and didn't keep a master of the clients finished project and you have to recover work from a final DVD. This is like using proxy streams to create a broadcast show. The quality is bad. Or, the client is trying to get someone to take media from a DVD authored by someone else who likely owns the copyright. (ie, the videographer or editor that edited their wedding together)
OR, you made a DVD, tossed the original media, and you only have the DVD to work from.

In any respect, this is NEVER a good workflow as you're dealing with lo-grade audio, and significantly reduced grade video. Then again, some folks just don't care that much about quality.

2. You're pirating DVDs for friends or internet distribution. Nothing more to say there.

Our Instant Surround book covers a lot of the AC3 and DTS ground, but it doesn't start shipping for another 3 weeks.
Tom Holman's book is decent on the subject, but it's DEFINITELY not a beginners book. Jay Rose barely sneezes at this subject in his 2 books. In other words, I dunno where to send you other than maybe looking at Dolby's site.

[Dwight Flynn]

Ok, but is there an alternative to ac3 that does not have all of these complications (again simplistic I know, but helpful).

Thanks

[Douglas Spotted Eagle]

There is DTS as an alternative, but again, it's a violation of their terms to decode for editing.

What is it you're wanting to use this for? DTS and AC3 are DELIVERY formats, not editing formats. WHen you encode to these formats, you are done with your project. Last step, no going back. In theory

[Dwight Flynn]

I am looking for a final delivery format, which if I have to do so (b/c as you pointed out snafu happens), I can go back and edit without breaking anyone's user terms. Also this helps because it gives me a range of better, more informed, choices with my created content.

Thanks

[Douglas Spotted Eagle]

there isn't one. Encoding to AC3 or DTS assumes you'll have the presence of mind to store the product in a raw, unencoded form somewhere, somehow. We make the client buy hard drives and we use those to store off product. You can deliver short projects in PCM audio with no problem. It is more robust than AC3, but takes more space.