[FFmpeg-user] How to set 3 specific metadata flags (ITU601/displayoffset) in FFmpegs IMX50 MXF-OP1a encoding?

tim nicholson nichot20 at yahoo.com
Mon Mar 30 13:23:39 CEST 2015

On 30/03/15 09:44, tim nicholson wrote:
> On 30/03/15 08:33, Christoph Gerstbauer wrote:
>>>> Hello Tim!
>>>> thank you, it works for PAL and NTSC (720x512/720x480) but there is a
>>>> just little bug for NTSC when encoding to 720x486 in "stored dimension"!
>>> My patch only deals with the addition of the display y offset metadata,
>>> it should not touch exisiting metadata, are you saying that the figures
>>> for 'Stored dimensions' are different with and without my patch?
>> Hello Tim, you are right.
>> I tried it with a non-patched ffmpeg version, and I got the same result:
> So possibly a different bug, or possibly even invalid frame sizes for
> IMX @NTSC, I will check the specs.

720x486 is a very odd size. In particular 486 would need rounding up the
next full macroblock size hence the additional 10 lines stored.

Its the same for HD 1920x1080, if you look at the stored size its 1088.
This usually gets done automatically by the coder for AVCI. As these
padding lines are at the end and not the top the offset of 0 is correct.

So I don't think this is wrong at all.

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

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