Loss of quality if encoding when encoding not needed

[steptoe]

Just out of curiosity, if I have a DVD that will fit without any encoding using CCE, but I let CCE encode it anyway does it actually drop any quality for the final output

If you encode the DVD so that the result is now obviously going to be more than 100% of the original source, surely it won't drop quality as the bitrate shouldn't change as you are actually increasing the final size and not trying to reduce the bitrate to fit the source onto a single disk


If I misunderstand any chance of an explanation as why the final quality may suffer

[communist]

Just out of curiosity, if I have a DVD that will fit without any encoding using CCE, but I let CCE encode it anyway does it actually drop any quality for the final output
Yes quality will be lower although it might not be easily visible.

If you encode the DVD so that the result is now obviously going to be more than 100% of the original source, surely it won't drop quality as the bitrate shouldn't change as you are actually increasing the final size and not trying to reduce the bitrate to fit the source onto a single disk

"more than 100% of the original source" in terms of file size? Quality wont be better because the encoder does not care at what bitrate the original was encoded. It will take the decoded frames and will apply the same compression it applies always.
Since MPEG2 compression used on DVDs is lossy, reencoding will result in lower quality as the encoder will treat everything it 'sees' in those frames as being part of the picture - though some of it may have been introduced by the first compression step. By applying another compression step you will further introduce such compression artifacts and amplify existing ones - regardless of a higher (less artifacts) or unchanged / lower (more artifacts) bitrate.