TMPGEnc Plus Conversion To DV - What's It Doing?

[Teshia]

Okay, here's a quick question. When you convert a video to DVD MPEG in TMPGEnc Plus, it goes through two stages. The first 50% of the conversion just shows a black screen, like no video is being encoded or something. Yet, when you look at the VirtualDub frameserver I've got running, it shows frames being served during this process. Also, the output file during this period never seems to go above zero bytes, so it doesn't appear to be building a file. Then at 50%, it starts to encoded the video from start to finish. During that time, the output file gets built. So my question is, what the heck is it doing during that first 50% of the encoding process?

[Baldrick]

It is called 2-pass VBR encoding.

2-pass VBR

In 2-pass VBR mode, the compressor will make two passes. In the first pass, it will compress the footage while trying to keep a constant quality, regardless of bitrate. It will then use the resulting bitrate (scaled to fit within the user-selected values) to do the final encoding. This results in the best relationship between compression and quality. It is, however, rather slow. If you use CBR at 8 Mb/s, you will end up with more or less the same quality, but the compression will not be as efficient. This means that the resulting file will be bigger, and you will not be able to fit as much video into one disc. If your movie has less than 1 hour, and you don't have any use for the extra space on the disc, you should use CBR to save on the encoding time.

from http://dvd-hq.info/Compression.html

[jimmalenko]

You will notice that if you load a file directly into TMPGEnc, it says "Analysing" in the middle of the black screen for the first 50%. It mustn't do this when frameserving I gather.

[bugster]

You will notice that if you load a file directly into TMPGEnc, it says "Analysing" in the middle of the black screen for the first 50%. It mustn't do this when frameserving I gather.

That depends on the exact version being used. Some older versions displayed nothing during the 1st pass. I can't remember exactly which version introduced the 'analysing' in the middle of the preview window though it has been there for quite a while.

[Teshia]

For the record, mine does not say "analysing" anywhere onscreen during the first 50% and I'm using Plus 2.55 - haven't felt a need to move into a newer version though, unless there have been vast improvements to their MPEG encoding process that I don't know about. Should I upgrade?