Encoding Overhead

[Slarty]

I'm trying to encode a couple of SVCD's so that they fit on one DVD-R. I'm okay with using TMPGenc+ and I manage to get it to re-encode the SVCD mpeg at a bitrate that gives me a file size of approx 45% of a total DVD-R.

When I come to author the DVD (I'm using DVDit PE) and create the VIDEO-TS folders for burning with Nero, it says that the total disk space now needed is more than 4.7Gb! How come?? I realise that there is some overhead when creating the DVD (which is why I used 45% of the total DVD-R size in TMPGenc), but on checking one of the films, it's jumped in size from 2Gb (approx) to just under 3Gb !!

Help appreciated as re-encoding each time using 'guess' bitrates takes a couple of hours a go!!

[SLK001]

There is about 100-150 MBytes of navigational overhead on a DVD. You need to take this into account when you calculate bitrates and sizes.

[Sulik]

Some DVD authoring tools are converting the MPEG audio to uncompressed LPCM (adding 1Mbps overhead just for audio)

[Slarty]

Thanks.

It looks like both DVDit PE and Sonic DVD Producer are both converting the audio to LDPCM, hence the large increas ein file size. What DVD authoring software will not convert ??

[SLK001]

DVDit PE can import .AC3 audio. I don't remember it ever converting the audio (or re-encoding the video).

[housepig]

DVD Lab will not reencode your files.

[Slarty]

So am I missing something here. I've taken an SVCD mpeg, stripped the sound (DVD2AVI), ran both files through TMPGenc to create a PAL DVD with MP2 audio (ES stream - audio/video). When I then import these into DVD Producer it appears to be converting the MP2 to LDPCM (AIFF) hence why my DVD folders are getting big.

How do I tell DVD Producer to convert the audio to AC3 then instead of PCM? Or am I misunderstanding something in the 'how to convert' area?!

[Slarty]

OK - I think I've worked out whats happening here.

First of all, the audio was being converted when it was loaded into DVD Producer because it didn't recognise the .mp2 extension - it had to be .mpa (even the audio was encoded correctly MPEG 1 Layer II - you would have thought the programmers would have checked inside the file rather than just an extension!)

Secondly, even though the video is was encoded in TMPGenc at a DVD compliant 352x576, DVD Producer only appears to accept 720x576 - anything different and it transcodes the files on import to 720x576 at a CBR of 7Mbps

Anyone know of some better software than DVD Producer or a way to get around the Video problem of being transcoded??