# [FFmpeg-user] Glossary: DAR, PAR, and SAR

Mark Filipak (ffmpeg) markfilipak at bog.us
Thu Oct 1 01:18:35 EEST 2020

```On 09/30/2020 06:08 PM, Jim DeLaHunt wrote:
> On 2020-09-30 13:09, Mark Filipak (ffmpeg) wrote:
>> I seek your comments regarding the following glossary entries (that have been reformatted to fit
>> email). Kindly take your time.
>>
>> -Mark.
>>
>> DAR (display aspect ratio [1]) [noun]: 1, … as a minimized, H:V, integer ratio (e.g.
>>   16:9, 4:3)…
>> (and similar wording for PAR and SAR):
>
>
> Is the term "minimized aspect ratio" already used in this domain? If not, then the related
> mathematics term "reduced fraction" may be a better inspiration than "minimized".

Excellent! I'll go for it.

>> SAR [noun]:…
>>   [2] A standardized set of picture sizes & aspects has been
>>       established:
>>                  display     DAR     picture     PAR    SAR = DAR/PAR
>>     16:9-2160: 3840 x 2160  16:9 : 3840 x 2160  16:9 :  1:1
>>      4:3-2160: 2880 x 2160   4:3 : 2880 x 2160   4:3 :  1:1
>>     16:9-1080: 1920 x 1080  16:9 : 1920 x 1080  16:9 :  1:1
>>      4:3-1080: 1440 x 1080   4:3 : 1440 x 1080   4:3 :  1:1
>>      16:9-576: 1024 x 576   16:9 :  720 x 576    5:4 : 64:45
>>       4:3-576:  768 x 576    4:3 :  720 x 576    5:4 : 16:15
>>      16:9-480:  853 x 480   16:9 :  720 x 480    3:2 : 32:27
>>       4:3-480:  640 x 480    4:3 :  720 x 480    3:2 :  8:9  [3]
>
>
> The formatting of the email garbles the table [2] enough that I can't be sure what I'm reading.
> Maybe insert printable delimiters into each line?

Hmmm... It's a table: rows and columns, like a spread sheet. Does making the column headers more
obvious work better?

display     DAR       picture     PAR      SAR = DAR/PAR
===========  ====     ===========  ====     =====
16:9-2160:  3840 x 2160  16:9  :  3840 x 2160  16:9  :   1:1
4:3-2160:  2880 x 2160   4:3  :  2880 x 2160   4:3  :   1:1
16:9-1080:  1920 x 1080  16:9  :  1920 x 1080  16:9  :   1:1
4:3-1080:  1440 x 1080   4:3  :  1440 x 1080   4:3  :   1:1
16:9-576:  1024 x 576   16:9  :   720 x 576    5:4  :  64:45
4:3-576:   768 x 576    4:3  :   720 x 576    5:4  :  16:15
16:9-480:   853 x 480   16:9  :   720 x 480    3:2  :  32:27
4:3-480:   640 x 480    4:3  :   720 x 480    3:2  :   8:9  [3]

Or is it the column centering that doesn't work?

--
What would you do if you woke up in a police state?
African-Americans wake up in a police state every day.
```