[FFmpeg-user] Question about encoding DVCPRO50

[Carl Zwanzig]

On 6/22/2023 2:11 PM, Paul B Mahol wrote:
>> okay it seems like there is no way to encode a true 48.8 mb/s DV50 file

> But DV50 are >= 50 mb bitrate

Telecom, video, and data storage are usually counted and suffixed in base 
10; computer stuff is base 2. (So bit rates are given in base 10 - 128kbps 
is 128000 bits per second, not 131072.)

50.0 / 1.024 = 48.8

If either ffmpeg or mediainfo is displaying a bit rate of 50,000,000 as 
"48.8", it's wrong :).


The IEC tried to remove the ambiguity of kilo/mega/giga/etc being either 
10^3 or 2^10 with the "bi" substitution
megabyte  (MB) = 1000 * 1000
mebibyte (MiB) = 1024 * 1024
gigabyte (GiB) - 1000 ^ 3
gibibyte  (GB) = 1024 ^ 3
etc

AFAICT very few people use the new ones. Nor do people agree on the meaning 
of capitalizing either letter (MB vs Mb vs mb or bps vs b/s).

Later,

z!