On Fri, 30 Mar 2018 02:39:13 +0200 Michael Niedermayer <mich...@niedermayer.cc> wrote:
> On Thu, Mar 29, 2018 at 10:12:50PM +0300, Timo Teras wrote: > > On Thu, 29 Mar 2018 20:29:44 +0200 > > Michael Niedermayer <mich...@niedermayer.cc> wrote: > > > > > On Wed, Mar 28, 2018 at 07:02:48PM +0300, Timo Teräs wrote: > > > > iTunes currently uses the 'cprt' atom to store the copyright > > > > notice and this patch fixes compatibility with majority of > > > > software that supports the 'ilst' atom. Other software and > > > > documentation using this: > > > > - AtomicParseley encodes and parses only 'cprt' > > > > - Most players recognize only 'cprt' > > > > - > > > > https://sno.phy.queensu.ca/~phil/exiftool/TagNames/QuickTime.html > > > > documents both tag types > > > > - http://mutagen.readthedocs.io/en/latest/api/mp4.html > > > > documents only 'cprt' > > > > > > > > ffmpeg mov reader properly parses the 'cprt' tag inside 'ilst' > > > > tag and functions correctly with streams produced with this > > > > commit. > > > > > > > > Since 'cprt' seems to be the current correct atom, it is used by > > > > default. "-movflags legacy_copyright" option is added to revert > > > > back to the old atom type in case that is needed. > > > > > > > > Signed-off-by: Timo Teräs <timo.te...@iki.fi> > > > > --- > > > > If the legacy option is not needed, I'm happy to resend patch > > > > just changing the atom types. > > > > > > why dont you store both ? > > > the old should do no harm or am i missing something ? > > > and it avoids the need for the user parameter (which few will > > > find if they run in a file that doesnt work) > > > > AFAIK, 'cprt' is the canonical tag and always has been for iTunes > > list. I tried to look where the current ffmpeg atom came from, but > > did not find anything conclusive. It might be copy paste error on > > ffmpeg from other container variants, and others who supports it in > > iTunes list is to support ffmpeg generated .movs. > > git log points to > bed4fc54c947b9e36d2103b400d438bfb4dd80dd > > This commit added both cpy and cprt, that makes your hypothesis not > fit very well That commit adds it to three places: - MOV mode which is basically in mov_write_udta_tag() using '\251cpy' which published in Apple docs - 3GP mode using 'cprt' which is in ISO standard - mov_write_ilst_tag() is iTunes which is non-documented The commit adds exactly one tag to each variant. To me my hyptothesis still looks correct. > did you ask the author, who added this ? Maybe he remembers where it > came from. > It would be better to understand where it came from before its changed @Baptiste: Any comment why \251cpy tag was used for iTunes list and not cprt? > If it was a typo or something like that, i agree that it should be > removed/replaced. I was assuming it come from some official > reference/software ... iTunes list format is unfortunately not documented. MOV and 3GP modes are standardized. Timo _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org http://ffmpeg.org/mailman/listinfo/ffmpeg-devel
