🚀 go-pugleaf

1. To be able to use a higher bit rate you will need to use an authoring application that supports Dolby Digital (AC3) audio. Another possible option would be to use a dual layer DVD+R DL disc (and a burner that can burn DL media), write a DVD Folder from DVDit and burn with a recent version of Nero.

3. You could store copies of larger (higher bit rate) versions of the MPEG-2 files on separate data DVDs to be used later, e.g. with an AC3 capable authoring application.

Thank you for your helpful suggestions.

Unfortunately, I put all of my money into a DVD- Recorder. According to some sources, there should shortly be a higher capacity DVD-R, but not now. But if I were, would the Dolby Digital AC3 have the same quality as PCM?

I appreciate your second suggestion, which seems to be the path of least resistance. As I understand, I would save my files as usual with MPEG, save them on separate DVDs and then wait for the technology to improve.

I think what I should also do is to divide my current project into 2 halves, and save 4 chapters on one disc with 5 dummy buttons (you click on the button but there is no file there), and 5 chapters on another disc with 4 dummy buttons. I understand that there is a way to save projects on 2 DVDs besides this way, but I have not figured out that, and I am not sure it would be better than just doing this manually.

I would welcome any other suggestions.

      But if I were, would the Dolby Digital AC3 have the same quality as PCM?




For people with normal ears AC3 audio (stereo at 192 or 224Kb/s) will sound just as good uncompressed PCM. The only case where I would consider using PCM instead of AC3 would be one where the audio is more important than the video.

      there should shortly be a higher capacity DVD-R, but not now.




First samples of DVD-R DL (dual layer) media are available at the moment. Just like DVD+R DL, they need burners that specifically support them. If you got a single layer burner at the moment, it won't work with either of the writable dual layer media.

Thank you for your message. That reinforces what I should do in saving my work.

Another question: what problems await me if I simply change the Advanced MPEG Settings, audio settings from PCM to MPEG Layer 2, audio bitrate, 192, using the Adobe MPEG Encoder. That will result in substantially smaller audio files. Will I have sync or other problems?

Will DVDit! be able to handle the new audio files without any problem?

With DVDit there is no advantage to using MPEG-1 Layer II compressed audio: DVDit will convert it right back into uncompressed PCM for the DVD it makes. And you could run into sync problems as DVDit isn't always entirely comfortable with MPEG audio.

If you are on NTSC and you would use an authoring applications which does allow MPEG audio, another drawback is that NTSC set top DVD players are not required to support it. Some do and some don't. Even those that do, will only send the audio to the analog output.

Ruud, you saved me an awful lot of time and aggravation. Thank you.
Looks like if I want to fit the project on one DVD, I will have to reduce the video quality to a bit rate of about 4500 kpbs--is the quality going to be awful?

With a total of 102 minutes of video in your project the bit rate for video plus audio can be 5.8Mb/s. After subtracting 1.6 for the uncompressed PCM audio that leaves 4.2Mb/s (4200Kb/s) for the MPEG-2 video. Depending on how easy or difficult your material can be compressed this can be easily sufficient for a quite acceptable video quality when you use Variable Bit Rate (VBR) encoding.

Difficult to compress is e.g noise, lots of motion, fine moving detail (like leaves, or a rippling lake) and hand held camera shots.

Your suggestions have been very good. One last question: what is VBR encoding and does it involve anything different from what I am doing already with exporting to Adobe MPEG Encoder. Thank you.

When you tell the encoder to use VBR, it will try to use the available bits to the best effect.

E.g. say that you have calculated that to fit all video in a project on a DVD, the MPEG would have to be encoded with a bit rate of 4Mb/s. Using CBR (Constant Bit Rate) everything would be encoded 4Mb/s; easy to compress sections which could have been encoded with less than 4Mb/s, as well as hard to compress parts which can't be encoded with 4Mb/s. "Can't be encoded" meaning that the encoder has to resort to heavy-handed measures which result in ugly artifacts. (Similar to using heavy JPEG compression on a still.)

With VBR the encoder would use an average bit rate of 4Mb/s. For the easy to compress sections it will use less and for the harder parts more than 4Mb/s. As a result you will see far less artifacts. And because the bit rate averages out as 4Mb/s, the resulting MPEG-2 file is just as large as the one made with CBR encoding.

Using VBR for everything isn't the most practical or best solution though. Say the highest bit rate you want to use is 7Mb/s and your project easily fits with that bit rate, there is no advantage to using Variable Bit Rate encoding: The encoder can't actually vary anything. :p If there isn't at least 1Mb/s difference between the calculated bit rate to fit your project and the highest bit rate you want to use, I would suggest to stick with CBR.

Thank you for your excellent explanation.

um...why not just burn a Dual Layer DVD-R, they play fine in 99% of set top
players anyway, forget compressing, you dont have too

plus Blu-Ray (25GB) will be out soon, so use DVD+/-DL (8.9GB) while u still
can

~ Connor

<Lev_Volkov@adobeforums.com> wrote in message
news:3bba6b77.3@webx.la2eafNXanI...
> Thank you for your message. That reinforces what I should do in saving my
work.
>
> Another question: what problems await me if I simply change the Advanced
MPEG Settings, audio settings from PCM to MPEG Layer 2, audio bitrate, 192,
using the Adobe MPEG Encoder. That will result in substantially smaller
audio files. Will I have sync or other problems?
>
> Will DVDit! be able to handle the new audio files without any problem?