15 hour rendering for PAL-NTSC conversion?

russellg wrote on 1/18/2005, 3:24 PM

I'm trying to build a dvd with DVD-AS, using 3 one-hour VOB files in PAL format. But I'm creating the dvd in NTSC format, so I assume it's doing the conversion during the Prepare stage. It's taking 15 hours to prepare the dvd, which seems ridiculously long. But it's only 9 and a half hours if I keep the project in PAL and don't do the conversion to NTSC (which also seems ridiculously long).

By contrast, I can do the same PAL-to-NTSC project in Cyberlink's Power Producer in about 5 hours, and the video looks great.

As a matter of fact, it looks better than the dvd produced by DVD-AS... Power Producer makes you select either a 1-hour, 2-hour, or 3-hour project, and says the video will be at 8Mbps, 4.6Mbps, or 3.1Mbps, respectively (to make it always fit in 4.7GB). So why is Power Producer able to produce 3 hours of video at 3.1Mbps, when DVD-AS requires me to "optimize" it down to 1.8Mbps to get it to fit into 4.7GB?

It seems that Power Producer has a really crappy user interface, but a great rendering engine, while DVD-AS has just the opposite. I want DVD-AS's great features, with reasonable rendering times, especially when converting from PAL to NTSC, which is unfortunately something that not many dvd-producing programs seem able to do at all.

Thanks for any help,
Russell

Comments

mbryant wrote on 1/19/2005, 12:55 AM

MPEG renders tend to be fairly slow, and I've found that rendering from PAL to NTSC makes it even slower. Depends on your PC speed etc, but 15 hours rendering for 3 hours of material does not surprise me. The encoder which DVD-A (and Vegas) use generally gives good quality, but it is not the fastest.

For a 3 hour video, if you use AC-3 audio, then a rate of around 3.1 or 3.2 should fit... 1.8 would be the rate if you had uncompressed (PCM) audio. Now, DVD-AS doesn't support AC-3, right? So, it sounds to me it is converting the audio to PCM, leaving less room for the video, which is why you are getting 1.8, which is why the quality will not be very good.

Does your Cyberlink software have AC-3 support? (or even MPEG audio). If so, I think that is the answer why it can use 3.1 Mbps.

Mark

russellg wrote on 1/19/2005, 11:47 AM

Thanks for the reply.

Cyberlink is using a "Dolby Digital Consumer Encoder" format for audio actually, and the other choice for an NTSC project is LPCM (it also supports MPEG-1 audio for PAL projects). So it sounds like you're right, the PCM (yes, that's what DVD-AS is using) is probably eating up a lot of my space.

But I guess the real issue is that it's taking 15 hours to render 3 hours of video. That's a full 3 times as long as Cyberlink, on the same machine, with the same source video. I mean, 5 hours with Cyberlink is long, but at least I can start it up before going to bed, and it'll be done in the morning. With DVD-AS, it still has another 7 or 8 hours to go!

Anyway, thanks for the reply...

Russell