[FFmpeg-devel] [PATCH 2/2] avformat/mxfdec: do not use AnyType when resolving Descriptors and MultipleDescriptors

[Tomas Härdin]

fre 2024-02-16 klockan 22:18 +0100 skrev Marton Balint:
> Using AnyType should not be a problem for proper MXF files because
> UIDs are
> supposed to be unique themselves. Unfortunately that is not the case
> for some
> broken files, so let's check the type more strictly.

Here's what S377m-2004 says:

> StrongRef: “One-to-one” relationship between sets and implemented in
> MXF with UUIDs. Strong references
> are typed which means that the definition identifies the kind of set
> which is the target of the reference.


So non-unique UUIDs are fine so long as their type sets them apart.
Therefore we should not use AnyType unless there is a good reason to do
so. UMID lookup would be such a reason. Resolving SourceClips and
TimeCodeComponents are not. And since we don't do any UMID lookup we
could just as well ditch AnyType entirely.

> Fixes ticket #10865.
> 
> Signed-off-by: Marton Balint <cus at passwd.hu>
> ---
>  libavformat/mxfdec.c | 19 ++++++++-----------
>  1 file changed, 8 insertions(+), 11 deletions(-)
> 
> diff --git a/libavformat/mxfdec.c b/libavformat/mxfdec.c
> index 4e4e3e7a84..446bcf3276 100644
> --- a/libavformat/mxfdec.c
> +++ b/libavformat/mxfdec.c
> @@ -2258,16 +2258,14 @@ static MXFPackage*
> mxf_resolve_source_package(MXFContext *mxf, UID package_ul, U
>  
>  static MXFDescriptor* mxf_resolve_descriptor(MXFContext *mxf, UID
> *strong_ref, int track_id)
>  {
> -    MXFDescriptor *descriptor, *file_descriptor = NULL;
> -    int i;

Mixing functional and style changes make the patch annoying to read.
Anyway it looks fine

/Tomas