Loss of quality when re-encoding ?

[mjkc]

Hi

Just a simple question I hope

If I take two MPEG VCD files and join them, in TMPGEnc for example, will there be a drop in quality from the original VCD file in the new file.

Along the same lines if I use TMPGEnc to cut a portion of a VCD file out will the resultant file loose quality once TMPGEnc has finished splitting it ?

Thanks in advance

[noobee]

no drop in quality.

[mjkc]

Thanks for the prompt reply

Does that also mean that if you were to encode a file to VCD and then run it through the encoder again set to VCD there also would be no drop in quality ? Just Curious

[mats.hogberg]

When you're cutting or joining, there's no encoding involved, thus no drop in quality. If you however encode something (using MPEG) there will be some loss in quality, regardless of input format.
So, even if you encode using exactly the same settings as when the MPEG used as input was created, there will be quality loss.
If the encoder was really clever, it could discover that the input and output format will be exactly the same, and refuse to encode (resulting in no quality loss) but that's not the case for any encoder I've come across.

/Mats