[FFmpeg-devel] [PATCH v3 3/3] avformat/mxfenc: prefer to use the existing metadata

[Marton Balint]

On Fri, 8 Jan 2021, Tobias Rapp wrote:

> On 08.01.2021 11:01, lance.lmwang at gmail.com wrote:
>> On Fri, Jan 08, 2021 at 09:09:34AM +0100, Tobias Rapp wrote:
>>> On 08.01.2021 07:32, lance.lmwang at gmail.com wrote:
>>>> From: Limin Wang <lance.lmwang at gmail.com>
>>>>
>>>> Please check metadata with below command:
>>>> ./ffmpeg -i ../fate-suite/mxf/Sony-00001.mxf -c:v copy -c:a copy out.mxf
>>>> ./ffmpeg -i out.mxf
>>>>
>>>>       company_name    : FFmpeg
>>>>       product_name    : OP1a Muxer
>>>>       product_version : 58.65.101o
>>>>       =>
>>>>       company_name    : SONY
>>>>       product_name    : eVTR
>>>>       product_version : 1.00
>>>>
>>>> So need to update fate-mxf fate test.
>>>>
>>>> Signed-off-by: Limin Wang <lance.lmwang at gmail.com>
>>>> ---
>>>> [...]
>>>
>>> In my opinion the MXF identification set should contain data about the
>>> application that wrote the current version of a file, not some previous 
> file
>>> version.
>> 
>> The example command shows what's change for the fate testing, if you want 
> to
>> update to use  your own product version, please use -metadata 
> product_version="xxxxx".
>
> It looks wrong that a MXF file that is muxed by FFmpeg pretends to be 
> written by a SONY application. I see that with "-codec copy" you can 
> avoid re-encoding of the video and audio streams, and thus might want to 
> indicate the A/V encoder software info somewhere separate from the 
> container format writer software. But this patch overrides both information.

We might remove company_name, product_name and product_version metadata in 
fftools/ffmpeg_opt.c similarly how creation_time is removed for automatic 
metadata copy.

Regards,
Marton