Wishlist/question: Policy for BWF headers/metadata?

[pjotrek-b]

I know this is currently out of the main scope of MediaConch, but:

Would it be possible to query descriptive metadata fields or the existence of BWF chunks? For example:

1) BWF: Check if "qlty" or "bext" chunk is present.

2) Descriptive metadata: For any media format, query if a title is set.

[kieranjol]

I think this could be possible now that we can create rules based on Mediatrace. I'd like to know the answer to this as well, as I couldn't find any example of how to create a rule using Mediatrace. I tried using Broadcast extension or bext in 'field' but it never seemed to catch the existence of the bext chunk.

 bext ❌ fail
Value: Broadcast extension
Operator: exists
Xpath: mmt:MicroMediaTrace/mmt:d[@n='Broadcast extension']

[JeromeMartinez]

We can test the BWF headers with MediaTrace, but we definitely lack of an assistant for that (permitting easy settings of the test based on the trace of the analyzed file). We'll provide the right formula soon (and later we'll add an assistant for MediaTrace policy)

[kieranjol]

That would be brilliant, Jerome. I don't know how to create the trace policy at all.

On 7 Nov 2016 12:52 p.m., "Jérôme Martinez" notifications@github.com wrote:

We can test the BWF headers with MediaTrace, but we definitely lack of an assistant for that (permitting easy settings of the test based on the trace of the analyzed file). We'll provide the right formula soon (and later we'll add an assistant for MediaTrace policy)

— You are receiving this because you commented. Reply to this email directly, view it on GitHub https://github.com/MediaArea/MediaConch/issues/163#issuecomment-258827767, or mute the thread https://github.com/notifications/unsubscribe-auth/ABEyvj8giJBbAledmzEePTfK9rAO_TVFks5q7x8HgaJpZM4Kpaf5 .

[dericed]

Hi @kieranjol, I'd like to make one as an example. Can you detail a bit what tests you'd like to use.

[pjotrek-b]

I think it'd be perfectly fine for the time being to live without any GUI assistance for the BWF-header use-cases (and the likes).

Just to avoid mixing things up: Would that also enable testing descriptive metadata fields (as mentioned above in my original note)?

[pjotrek-b]

Sorry for the "small-finger-whole-hand" requests ;)

[pjotrek-b]

@dericed: BWF For audio preservation, I guess checking existence of the following RIFF-chunks would be useful: (Importance (and chance to exist in real-world) are in order of appearance)

• bext
• qlty
• levl

Unless MediaInfo already is able to parse BEXT chunk, I think going for values inside these chunks would be overkill. I guess.

[JeromeMartinez]

I think it'd be perfectly fine for the time being to live without any GUI assistance for the BWF-header use-cases (and the likes).

Just to be clear: info about an assistant is not part of the issue ticket, was just for information about our long term goal. Here Dave will provide a ready to use policy so you'll see how to use MediaTrace capability in MediaConch by editing the MediaTrace formula in the UI (without assistance, only text) or in the XML.

Would that also enable testing descriptive metadata fields (as mentioned above in my original note)?

Everything you can see in MediaTrace can be tested, BWF "Originator" or "Description" included (there is not "title" field in bext). So yes.

Unless MediaInfo already is able to parse BEXT chunk (...)

Just drag 'n drop a BWF file in MediaInfo, click on "Wave" chunk, then click on "Broadcast extension", and you'll see that bext chunk is already parsed ;-).

[kieranjol]

@dericed, Peter's examples look good. I'd also like to be able to check if pixel aspect ratio is explicitly declared in a container, as mediainfo reports 1:1 if there is no PAR info. So I guess a check for that info in a pasp atom in mov, or vprp chunk in avi? I've no pressing need for this, but it would be good to see an example so that I could experiment further.