read_intervals 给定时间范围不匹配的 ffprobe 输出帧

Question

我已经在 here 阅读了 ffprobe 文档。

我不知道为什么我的第一帧时间是11.745秒，即使给出“-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

正如文件所说，

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.

更正 link 到记录此选项的部分 - https://www.ffmpeg.org/ffprobe.html#Main-options

read_intervals 给定时间范围不匹配的 ffprobe 输出帧

ffprobe output frame with read_intervals no match given time range

video

ffmpeg

webm

ffprobe