Hello everybody! Does anyone knows if it is possible to insert permanent subtitles into an AVI without re-encoding again? If so, how can I do that? If not, how can I do it without loosing video quality and keeping almost the same file size. Thanks for your help.
Not possible. To do it without re-encoding means softsubs, which can easily be disabled or removed. To make it permanent means making the subs part of the video; so re-encoding is essential. To do it without losing quality you would need to use a lossless codec, this however would most likely mean a massive filesize increase. Assuming that your source is already compressed, then you have to waste bits preserving old artifacts whilst trying not to introduce new ones, plus subtitles are hard to compress.