[FFmpeg-user] Problem with astats and adrawgraph

Michael Koch astroelectronic at t-online.de
Mon Nov 25 13:39:43 EET 2019

Am 25.11.2019 um 12:04 schrieb Paul B Mahol:
> On 11/25/19, Michael Koch <astroelectronic at t-online.de> wrote:
>> Am 25.11.2019 um 00:08 schrieb Michael Koch:
>>> I just found the solution to this problem myself:
>>> astats=metadata=1:reset=1,adrawgraph=m1=lavfi.astats.1.RMS_level
>>> The underline character is missing in the documentation, where the
>>> option is called "RMS level dB". Same problem for most other options too.
>> This command line works as expected:
>> c://ffmpeg/ffmpeg -i P1000479.mov -lavfi
>> astats=metadata=1:reset=1,adrawgraph=m1=lavfi.astats.1.RMS_level:mode=line:slide=scroll:min=-90:max=0
>> -pix_fmt yuv420p -t 5 -y test.mp4
>> However when I try to do exactly the same thing two times and combine
>> the videos with vstack, then I get warnings "More than 1000 frames
>> duplicated" "More than 10000 frames duplicated" and FFmpeg becomes
>> extremely slow:
>> c://ffmpeg/ffmpeg -i P1000479.mov -lavfi
>> [0]astats=metadata=1:reset=1,adrawgraph=m1=lavfi.astats.1.RMS_level:mode=line:slide=scroll:min=-90:max=0[1];[0]astats=metadata=1:reset=1,adrawgraph=m1=lavfi.astats.1.RMS_level:mode=line:slide=scroll:min=-90:max=0[2];[1][2]vstack
>> -pix_fmt yuv420p -t 5 -y test.mp4
>> What's wrong with this command line?
> Can not reproduce.
> Please provide input files.


This is a one second segment of my video (and is produces the same 
warnings as above), made with
ffmpeg -i P1000479.mov -c:v copy -c:a copy -t 1 -y P479_1s.mov
It's normal that the content is mostly black (with a few stars) and 
audio is only background noise.


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