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

[Michael Niedermayer]

On Wed, Jun 03, 2015 at 04:28:48PM +0200, Christoph Gerstbauer wrote:
> >>yes, this happens because 50mbit/sec is not correct
> >>a max framesize of 208541 results in a bit rate of max
> >>49.999840 mbit/sec, IIUC thats what the spec means by 50mbit/sec
> >The spec actually says "Up to 50Mb/s" and "Up to 208541" that being the
> >highest value that comes out below the the 50Mb/s. So I tend to agree
> >with Michael.
> >
> 
> Hi, i have made a short excel calulation and I think that these
> settings/syntaxes should be the correct ones for PAL/NTSC D-10:
> Do you agree?
> 
> 
> 	
> 	
> 	
> 	
> 	
> 	
> 	minrate
> 
> 	
> 	framerate 	max coded 	bits/byte 	bufsize 	
> 	maxrate
> 
> 	
> 	
> 	framesize (Bytes) 	
> 	rc_init_occupancy 	video bitrate
> IMX50 	PAL 	25 	250000 	8 	2000000 	
> 	50000000
> 
> 	
> 	
> 		
> 	
> 	
> 	
> IMX40 	PAL 	25 	200000 	8 	1600000 	
> 	40000000
> 
> 	
> 	
> 		
> 	
> 	
> 	
> IMX30 	PAL 	25 	150000 	8 	1200000 	
> 	30000000
> 
> 	
> 	
> 		
> 	
> 	
> 	
> 
> 	
> 	
> 		
> 	
> 	
> 	
> 
> 	
> 	
> 		
> 	
> 	
> 	
> IMX50 	NTSC 	29,97003 	208541 	8 	1668328 	
> 	49999840,16
> 
> 	
> 	
> 		
> 	
> 	
>

> IMX40 	NTSC 	29,97003 	166833 	8 	1334664 	
> 	39999920,08

i seem to have missed this reply, my question is basicylly the same
as tims, where does the limit resulting in 39999920 come from ?
is there some specification that limits the VBV buffer size to a
lower value for "40mbit/sec" than "50mbit/sec" ?

[...]
-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

When you are offended at any man's fault, turn to yourself and study your
own failings. Then you will forget your anger. -- Epictetus
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