[FFmpeg-devel] [PATCH v14 4/5] libavformat: Remove MAX_PATH limit and use UTF-8 version of getenv()

[nil-admirari at mailo.com]

> I like the version check. I don't know about all the derivatives
> of AviSynth, but I assume you have checked that it's valid for
> the common ones (or at least the original non-Plus variant)?

Interface version was changed to 7 in 2020:
https://github.com/AviSynth/AviSynthPlus/commit/40900dc1c54c14ea9f188c7242b88d464d067a44
three years after utf8 was implemented. If I'm not mistaken, there is no way to check
for a particular revision.

> Two ideas came to my mind how this could be done better.
> What's actually needed here is not a string conversion, we need
> a valid and usable filename, and the function could be more
> something like "get_ansi_filename()".
>
> The first thing that this function could do is to convert the
> the filename to ANSI and right back to UTF-8, then compare the
> UTF-8 result with the original UTF-8 string. When both are equal,
> we know that the conversion is safe, otherwise we know that it
> won't work.
>
> Then, we can use the win32 API GetShortFileName(). Which returns
> file and directory names in 8.3 notation which (IIRC) contains
> only letters which are valid in the ANSI code page.
>
> 8.3 file names do not always exist (depending on system config), 
> but it's always worth trying.
>
> Should both of these procedures fail, we could at least output
> a useful message, explaining why it doesn't work.
>
> Let me know what you think.

Too much work for something that was fixed on AviSynth+ side two years ago.