ffprobe get video volume of time interval

blumenwesen · 10-20-2023, 08:23 AM

Try using ffprobe to determine the average volume of a video section.
Judging by my search, it is possible only with amovie and not with volumedetect.

As an example using ffmpeg:

Code:

$ ffmpeg -hide_banner -ss 00:00:10.0 -to 00:00:15.0 -i "FILE.mp4" -af volumedetect -vn -f null - 2>&1 | awk '/mean_volume:/ {print $5}'
# output:
# -19.4

An error occurs when the start time "75%+#1" has been set:

Code:

$ ffprobe -v error -hide_banner -read_intervals 75%+#1 -show_entries frame=pkt_pts_time:frame_tags=lavfi.astats.Overall.RMS_level -of default=noprint_wrappers=1:nokey=1 \
-f lavfi -i amovie="FILE.mp4",asetnsamples=$(ffprobe -i "FILE.mp4" -v error -hide_banner -show_entries stream=sample_rate -of default=noprint_wrappers=1:nokey=1),astats=metadata=1:reset=1
# output:
# Could not seek to position 75000000: Invalid argument
# Could not read packets in interval id:0 start:75 end:+#1

Is there another more effective way to define the start and end time for the volume output, as a variable in time or in seconds?
thanks for help

blumenwesen · 10-21-2023, 04:45 PM

I've picked the scenes out now, but after the output the program does not end.
Can the script be adjusted so that it does not wait until the file has run through completely?

Code:

ffprobe -v error -hide_banner -show_entries frame=pkt_pts_time:frame_tags=lavfi.astats.Overall.RMS_level -of default=noprint_wrappers=1:nokey=1 \
-f lavfi amovie="FILE.mp4",astats=metadata=1:reset=1,aselect="between(t\,10\,10.1)"
# output
# -27.291128
# -26.758702
# -26.948367
# -26.799456
# ... after endless ſĦ  ��   ᕦ_…-·@    ��   ĦŊ waiting time ... exit

blumenwesen · 10-22-2023, 04:37 PM

Seems like I'm the only expert here, so I helped myself again.
Should have replaced 'aselect="between(t\,10\,10.1)"' with 'atrim=1000:1002'.