[FFmpeg-devel] [PATCH v4 3/3] avformat/mxfenc: prefer to use the configured metadta

emcodem at ffastrans.com emcodem at ffastrans.com
Tue Jan 26 11:20:30 EET 2021


Am 2021-01-26 00:34, schrieb Marton Balint:

>> Uhm guys, it is very bad practice: if you just insert a different 
>> manufacturer name then you just cheat. SMPTE 377 has a clear statement 
>> about what goes to the identification, you cannot just write the infos 
>> from a different program there.
> 
> Libavformat is a library/SDK, not an application. For most
> identification fields SMPTE 377 talks about the application which
> created the file, which can be anything using libavformat libraries.
> Feel free to quote if you have a more exact specification.
> 
>> 
>> What you can do instead is to push both identifications, the old one 
>> and the one from the current program into the identification array, 
>> this way the processing chain can be reconstructed. Unforutnately i 
>> have never seen anyone doing this besides Opencube.
>> 
>> Also, note that broadcasters currently are using the identification 
>> string, looking for "ffmpeg" in order to sort out non compatible 
>> XDCAMHD
>> mxf: ffmpeg does not write some mandatory metadata fields as mentioned 
>> here: https://trac.ffmpeg.org/ticket/5097 this leads to sony devices 
>> not accepting the ffmpeg mxf container - which again leads to ffmpeg 
>> mxf wrapper for XDCAMHD not being accepted by our public broadcaster.
> 
> Maybe they should post patches instead of having workarounds? And I
> explained, libavformat MXF muxer will still be identifiable, but the
> proper field will be used for identifying the SDK used, not
> Company/Product but Toolkit/Platform.

Sorry, there seems to be some confusion in this thread, the first 
submission seemed to target the "automatic copy" of the existing 
metadata but the updated version removes this automatism. Please ignore 
my comment as it is totally ok to provide input options for 
company_name, product_name, product_version but not automatically 
reflect the ones from the input.


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