On Tue, 08 Mar 2022 12:48:35 +0100 Anton Khirnov <an...@khirnov.net> wrote: > Quoting Niklas Haas (2022-03-04 16:03:06) > > From: Niklas Haas <g...@haasn.dev> > > > > I arbitrarily decided to use the syntax 'opt=@filename' to match e.g. > > `curl -Ffield=@filename`, and also because @ is not a valid hex > > character, nor does it conflict with any other common shell or ffmpeg > > syntax. > > > > This is arguably somewhat clunky because it does not round-trip with > > av_opt_get - you will get back a hex interpretation of the loaded file, > > rather than the filename it was loaded from. It also implies a (perhaps > > unnecessary) memcpy from mapped file memory into a allocated memory. > > This is unfortunately necessary because there's no way for us to know > > whether av_free or av_file_unmap is needed to clean up previous option > > values. > > > > The motivating use case was the introduction of several new binary > > options for vf_libplacebo, but other filters that currently rely on > > manual file-path loading could benefit from it as well. > > Sorry, I think having an arbitrary file loader in the options parser > will be an endless security nightmare. > > The alternative I had in mind was having ffmpeg.c itself do the file > loading. This will be require some modification of the options parsing > code in cmdutils.c and also extending the mechanisms we use to pass > options to filters. > > I can try to make a POC in a few days.
I think that is the better approach, too. I went for this approach because it was the easiest to implement, not because it makes the most sense. I do think that it's fine for ffmpeg.c to do this, but springing it upon unsuspecting API users *in general* is, well, in retrospect, not something I want to have my name attached to. I think that I would drop the second half of this commit (keeping only the introduction of `av_set_string_from_filepath`), and then make ffmpeg.c use it for cmdlist arguments starting with '@' as a separate commit. _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-devel To unsubscribe, visit link above, or email ffmpeg-devel-requ...@ffmpeg.org with subject "unsubscribe".
