FFmpeg 4.1.11
Since* 2.4
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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

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)

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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