Den 07.01.2024 23:35, skrev Andrew Randrianasulu:
пн, 8 янв. 2024 г., 01:31 Andrea paz <[email protected]>:
I don't quite understand how ffmpeg considers the various aspect ratios. However from the site lurkertech you pointed to (and from which I had taken some definitions put in the manual) PAR and SAR are not the same thing: PAR is about pixel shape and size; SAR is about frame shape and size.
To change the manual I would like to be sure that ffmpeg really considers PAR=SAR.
lets wait until ffmpeg-users reply to just send email :)
The wikipedia article section "Confusion with display aspect ratio" points out: https://en.wikipedia.org/wiki/Pixel_aspect_ratio#Confusion_with_display_aspe... Pixel aspect ratio is often confused with different types of image aspect ratios; the ratio of the image width and height. Due to non-squareness of pixels in Standard-definition TV, there are two types of such aspect ratios: /storage aspect ratio/ (/SAR/) and /display aspect ratio <https://en.wikipedia.org/wiki/Display_aspect_ratio>/ (abbreviated /DAR/, also known as /image aspect ratio <https://en.wikipedia.org/wiki/Image_aspect_ratio>/ and /picture aspect ratio <https://en.wikipedia.org/wiki/Picture_aspect_ratio>/). Also, /pixel aspect ratio/ (/PAR/) is also known as /sample aspect ratio/ (abbreviated /SAR/) in some industrial standards (such as H.264 <https://en.wikipedia.org/wiki/Advanced_Video_Coding>^[2] <https://en.wikipedia.org/wiki/Pixel_aspect_ratio#cite_note-2> ) and output of programs (such as /ffmpeg <https://en.wikipedia.org/wiki/Ffmpeg>/^[3] <https://en.wikipedia.org/wiki/Pixel_aspect_ratio#cite_note-3> ). Note the reuse of the abbreviations /PAR/ and /SAR/. This article uses only the terms pixel aspect ratio, display aspect ratio and storage aspect ratio to avoid ambiguity. And in Note 3 "ffprobe shows PAR as SAR" <https://trac.ffmpeg.org/ticket/1776>. ffmpeg.org. Retrieved 2022-06-10. https://trac.ffmpeg.org/ticket/1776