DVDR questions

[Digiface]

What's difference between re-encoding and downsampling? And how many passes are in original DVD? Is it 9? Is quality loss notable if video is re-encoded to example 5 pass?

[guns1inger]

Re-encoding and downsampling are two entirely different concepts.

Commercial DVDs are not encoded in the same way you and it encode. Mostly they are done with expensive hardware encoders, with a lot of hand tweaking of settings. For instance, every chapter point is identified to the frame before encoding, so the encoder knows to drop an I-frame at each chapter stop.

There is no visual difference between 3 passes and more passes in 99.99% of cases when using CCE. If you analyze the bitrate spread on a purely numeric basis you will find continued refinement of the data allocation up to around 5 passes, and only nominal change after than. None of this makes any real difference to the image itself.

Considering an encoder like ProCoder can produce equal (some say better) image quality in only two passes makes one question the need to do 9 pass encodes, other to say you can. I suspect that only those who drive red sports cars with a blond half their age sitting next to them really believe 9 passes are a must - and they need to take a little blue pill to do 9 passes anyway.