codecview

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:

block

Display block partition structure using the luma plane.

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

qp

Display quantization parameters using the chroma planes.

mv_type, mvt

Set motion vectors type to visualize. Includes MVs from all frames unless specified by frame_type option.

Available flags for mv_type are:

‘fp’

forward predicted MVs

‘bp’

backward predicted MVs

frame_type, ft

Set frame type to visualize motion vectors of.

Available flags for frame_type are:

‘if’

intra-coded frames (I-frames)

‘pf’

predicted frames (P-frames)

‘bf’

bi-directionally predicted frames (B-frames)

Examples

• Visualize forward predicted MVs of all frames using ffplay:

  ffplay -flags2 +export_mvs input.mp4 -vf codecview=mv_type=fp
  

• Visualize multi-directionals MVs of P and B-Frames using ffplay:

  ffplay -flags2 +export_mvs input.mp4 -vf codecview=mv=pf+bf+bb