Visualize information exported by some codecs.
Some codecs can export information through frames using side-data or other means. For example, some MPEG based codecs export motion vectors through the export_mvs flag in the codec flags2 option.
The filter accepts the following option:
- mv
-
Set motion vectors to visualize.
Available flags for mv are:
- pf
-
forward predicted MVs of P-frames
- bf
-
forward predicted MVs of B-frames
- bb
-
backward predicted MVs of B-frames
Examples
-
Visualizes multi-directionals MVs from P and B-Frames using ffplay:
ffplay -flags2 +export_mvs input.mpg -vf codecview=mv=pf+bf+bb