[FFmpeg-user] Questions about readout important metadata from DPX files ("logarthmic/linear") and recreate DPX with same metadata

[tim nicholson]

On 16/03/15 11:17, Christoph Gerstbauer wrote:
>> Imagemagick claims to support:-
>>
>> dpx:film.frame_rate
>> dpx:television.frame_rate
>>
>> Graphicsmagick:-
>>
>> dpx:mp.frame.rate
>>
> Thank you, Tim!
> 
> I found also two at graphics magick:
> 
> dpx:mp.frame.rate
> tv.temporal.sampling.rate

Yes, smpte S268 refers to field 66 as "Temporal sampling rate or frame
rate (Hz)".

Pity the two projects use different labels for the standard fields its
easy to miss which matches what as it stands....


> 
> It quite interessting: sometime the first (dpx:mp.frame.rate
> ), sometime the second (tv.temporal.sampling.rate
> ) has a useable value.
> 
> I made different tests.
> For example AFTER EFFECTS and ARRISCAN Filmscanner always writes into
> "tv.temporal.sampling.rate".
> AJA Capturing cards write into "dpx:mp.frame.rate" (e.g. 25), into
> "tv.temporal.sampling.rate" they write "4.60285e-041".
> 

Both are 32bit real values, but that is a bizzarre figure that I assume
must be digital detritus. I find AJA cards generally seem to "do their
own thing" when it comes to metadata, some of their .mov fields are way
different to everyone else's (like not setting the aspect ratio on HD
ingests)

> 
> Best Regards
> Christoph
> [...]

-- 
Tim.
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