[FFmpeg-user] Aspect Ratios: DAR, SAR and Frame Size
adishavit at gmail.com
Mon Jan 13 15:28:31 CET 2014
I have a video for which ffmpeg -i prints: Stream #0:0: Video: vp8,
yuv420p, 352x240, SAR 10:11 DAR 4:3, 15 fps, 15 tbr, 1k tbn, 1k tbc
As can be seen:
- The reported frame size is 352x240. This is an aspect ratio (AR) of
- SAR = 10:11
- DAR = 4:3
I have a few questions about these AR values:
1. Obviously, the frame size is the decoded size of the frame.
However, what do DAR and SAR mean in this context when they are both not
2. How many pixels are *actually* stored in each frame before any
stretching and/or padding occurs?
3. Does ffmpeg only stretch or does it also pad the frame to fit the
4. My usage does not care about the displayed video aspect-ratio, but I
would *really *like to avoid any padding and also reduce any unnecessary
processing (like stretching/scaling).
Is it possible to tell ffmpeg to do decode the frames/pixels while
keeping their internal AR and avoiding any padding and/or stretching?
Thank you and warm regards,
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