[FFmpeg-user] IMX50 NTSC framesize differs to the SMPTE 356M-2001 Standard - why?

[Christoph Gerstbauer]

>> Hello Tim,
>>
>> for IMX30 PAL/NTSC I have the same values like you.
>>
>> whats your buffers/init_occupancy for IMX50 NTSC?
>>
> Not sure I've ever had to do it, but a colleague uses an exact 50000000
> bit rate which gives a 1668334 buffer and frame size of 208541 if all
> figures are rounded to integers.
>
> These files have generally been accepted the other side of the Atlantic.
> As I've said before, the coder has got to reconcile a conflicting set of
> integer values when dealing with NTSC frame rates. It would be
> itneresting to diff frames made using the values above to those made
> using your values derived by working back from the exact integer frame
> size instead of forward from the bit rate.
So I dont have to set the "buffers/init_occupancy" an general or just in 
the NTSC case?
All what I have to set is the videobitrate itself?

Current syntax part:
-minrate 49999840 -maxrate 49999840 -b:v 49999840 -bufsize 1668328 
-rc_init_occupancy 1668328

Alternativ syntax:
-minrate 50000000 -maxrate 50000000 -b:v 50000000

So there is no need to set "bufsize" and "rc_init_occupancy"?

Best Regards
Christoph


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