[FFmpeg-user] Problem with astats and adrawgraph

Michael Koch astroelectronic at t-online.de
Tue Nov 26 18:48:57 EET 2019

Am 26.11.2019 um 17:32 schrieb Michael Koch:
> Am 26.11.2019 um 14:26 schrieb Paul B Mahol:
>>> I have a new example with testsrc2 and anoisesrc. There is no input 
>>> file
>>> required for reproducing.
>>> There are two graphs: The first one uses signalstats and drawgraph, and
>>> the second one uses astats and adrawgraph. The problem is that the two
>>> graphs don't advance with the same speed in X direction. Do you have an
>>> idea how to make them synchrone?The video width is the same in both
>>> cases, otherwise vstack wouldn't work.
>>> The speed of drawgraph is correct, 1 pixel per frame. The speed of
>>> adrawgraph is too fast.
>>> Other question: reset=1 in astats means that the calculation result is
>>> reset after each frame. But how does the filter know when a frame ends,
>>> if the input of this filter is only an audio signal?
>>> c://ffmpeg/ffmpeg -f lavfi -i testsrc2=size=hd1080:duration=10:rate=25
>>> -f lavfi -i anoisesrc=d=10:c=pink:r=48000 -lavfi
>>> [0]signalstats,drawgraph=m1=lavfi.signalstats.YAVG:mode=line:slide=scroll:min=0:max=255,settb=1/25[G1];[1]astats=metadata=1:reset=1,adrawgraph=m1=lavfi.astats.1.RMS_level:mode=line:slide=scroll:min=-90:max=0,settb=1/25[G2];[G1][G2]vstack,settb=1/25 
>>> -r 25 -y test.mp4
>> Use asetnsamples, to change size of audio frame to match you video FPS.
> At which place would you insert it? I did insert 
> asetnsamples=n=48000/25 before astats and now I get "Error while 
> filtering: Cannot allocate memory"

It works when I replace 48000/25 by 1920. Problem solved.


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