ffprobe输出帧，其read_intervals没有匹配给定的时间范围

Question

I have read ffprobe document at here .

I don't know why my first time of the frame is 11.745 seconds, even given "-read_intervals 12%13". (12sec ~ 13sec )

$ ffprobe -i chrome.webm -show_frames -select_streams v:0 -read_intervals 12%13 -hide_banner -loglevel panic

[FRAME]
media_type=video
stream_index=0
key_frame=1
pkt_pts=11745
pkt_pts_time=11.745000
pkt_dts=11745
pkt_dts_time=11.745000
best_effort_timestamp=11745
best_effort_timestamp_time=11.745000
pkt_duration=33
pkt_duration_time=0.033000
pkt_pos=717643
pkt_size=5864
width=480
height=270
pix_fmt=yuv420p
sample_aspect_ratio=1:1
pict_type=I
coded_picture_number=0
display_picture_number=0
interlaced_frame=0
top_field_first=0
repeat_pict=0
[/FRAME]
...

Answer 1

As the document says,

Note that seeking is not accurate, thus the actual interval start point may be different from the specified position. Also, when an interval duration is specified, the absolute end time will be computed by adding the duration to the interval start point found by seeking the file, rather than to the specified start value.

Correct link to section documenting this option - https://www.ffmpeg.org/ffprobe.html#Main-options